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General Category => Pics and Vids => Topic started by: chdfarl on November 06, 2014, 10:04:43 AM
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https://www.youtube.com/watch?v=Q7rDlCHKaOI (https://www.youtube.com/watch?v=Q7rDlCHKaOI)
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So which bike did you like the most, chdfarl? The Zero or the Brammo?
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Without a doubt the Brammo topped the Zero in my opinion. The Empulse is a bit of a pig on the scales but it's not felt on the seat. But since I mentioned the seat the Brammos was far less comfy.
I was disappointed that neither would wheelie and it left me wondering where all that torque was hiding. That might be that I left it in Eco mode but the salesman said that it wasn't that far off of the sport mode. That said the Empulse feels like a motorcycle with stronger acceleration and braking, though in my assessment the brake fork and wheel sizes are overdone and a big part of the weight issue. The things got liter bike components on a bike with the HP of a 500. That is where my criticism of the bike ends its beautiful and fun.
The Zero S on the other hand looks very confused to me. It seems too tied to its roots as a dirt bike but trying to be a commuter while looking like an overweight motard. Now though I felt that the acceleration was quite Burgmanesque (I refer to the Suzuki Burgman a large displacement scooter) the mid-range speed, brakes and overall ride was close to the Brammo.
No doubt the Zero lovers are up in arms at this moment petitioning to boot me but in the end if I were to buy an electric motorcycle today it wouldn't be the Zero S or the Brammo Empulse it would be the FX but only since the Engage was shelved.
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My zero will throw anyone into the back of the seat if they are not gripping the tank tightly every time you use max throttle.
Not sure what my settings are on the size 6 controller yet. Haven't ridden a stock S or SR yet to compare, if I did I would definitely use sport mode to get the top acceleration. Then switch to eco with 100% torque, 0% regen, 100% brake regen to compare it to.
When my regen is at 0% on the app the bike feels weak but still a little better than my ninja 250. With it at 60% it was enough to make my friend get light headed, something he says only happens with really fast bikes he has ridden. He has not tried it at 100% yet.
How was shifting on the Brammo?
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I like the Zero, not because I think it is a better motorcycle than the Brammo Empulse, but because I use it for running errands, carrying stuff and just getting around, not for sport. If I did, I would not be happy with the Zero's suspension, brakes and high speed handling, compared with the Empulse. But all I want is basic transportation that requires minimal servicing, can be charged from my home's 120V outlet, is easy to operate, quiet and doesn't have a clutch or transmission to mess with. Also, my Zero dealer is located only about 8 miles (a 15-minute motorcycle, or a 50-minute bus ride plus over an hour of walking) away.
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My zero will throw anyone into the back of the seat if they are not gripping the tank tightly every time you use max throttle.
Not sure what my settings are on the size 6 controller yet. Haven't ridden a stock S or SR yet to compare, if I did I would definitely use sport mode to get the top acceleration. Then switch to eco with 100% torque, 0% regen, 100% brake regen to compare it to.
When my regen is at 0% on the app the bike feels weak but still a little better than my ninja 250. With it at 60% it was enough to make my friend get light headed, something he says only happens with really fast bikes he has ridden. He has not tried it at 100% yet.
How was shifting on the Brammo?
What bike do you own??
My little FXr is everything but slow, I doubt a sr could even keep up 0 to 70; if I can keep the wheel down
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My zero will throw anyone into the back of the seat if they are not gripping the tank tightly every time you use max throttle.
How was shifting on the Brammo?
That sounds like an offer to ride it! ;)
Shifting the Brammo or any other bike is not an issue to me. I see it as part of the driving experience and the clutch is completely unnecessary. At first I was scared not to use it since power shifting can be hard on transmissions of ice bikes and it was a demo bike but with an electric there's no stress. So in my video half way through I stopped using the clutch even for downshifts. Heres one thing the direct drive fans overlook, What happens if your motor burns up and locks the back tire. There is no free wheeling then, so have a nice trip.
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I own Electric Cowboys 2013 S ZF11.4 Race bike; then one he took up pikes peak.
It has a ventilated motor with full ceramic bearings.
Size 6 controller with custom programming, it was de-tuned a little from race settings but is faster than a 2014 SR
Linderman Adjusted suspension (DS)
Gearing reduced for higher speed.
Yamaha dirtbike master cylinder for really crips braking
I don't have a setup where I can get the 0-60 time as I wear my camera inside my helmet which would require me to look down in my tank area where the koso display is instead of looking forward lol
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I like the Zero, not because I think it is a better motorcycle than the Brammo Empulse, but because I use it for running errands, carrying stuff and just getting around, not for sport. If I did, I would not be happy with the Zero's suspension, brakes and high speed handling, compared with the Empulse. But all I want is basic transportation that requires minimal servicing, can be charged from my home's 120V outlet, is easy to operate, quiet and doesn't have a clutch or transmission to mess with. Also, my Zero dealer is located only about 8 miles (a 15-minute motorcycle, or a 50-minute bus ride plus over an hour of walking) away.
Well you could do that stuff with the Brammo. They sell a storage box and doesn't the charge cord plug into the wall like the Zero. You could ride the Empulse without shifting it either.
Im happy people buy both bikes since they are both electric and American. I don't understand why some people (not you Richard230) feel that they should pick a team. Personally I don't like the looks of the Zeros even the FX and the S and one could assume the DS feels very scooter like to me and I like to play on my bikes so they aren't for me but no doubt they are a good simple commuter.
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I own Electric Cowboys 2013 S ZF11.4 Race bike; then one he took up pikes peak.
It has a ventilated motor with full ceramic bearings.
Size 6 controller with custom programming, it was de-tuned a little from race settings but is faster than a 2014 SR
Linderman Adjusted suspension (DS)
Gearing reduced for higher speed.
Yamaha dirtbike master cylinder for really crips braking
I don't have a setup where I can get the 0-60 time as I wear my camera inside my helmet which would require me to look down in my tank area where the koso display is instead of looking forward lol
ahhh how I love hotroded zeros. They get sooooo fast
Just curious what is top speed?
And have you ever tried?
30 tooth front and 98 rear? Or do you have 25 98?
30 and 98 was pretty fast for me. Not quick but Wow
Sorry to side track the thread
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Side track? that's not side tracking we're discussing the Zero and I love seeing and discussing hot-rodded vehicles, period! And those are good questions.
Now ill derail the topic but not really. Is the lack of real punch on those stock bikes due to the linear settings On the Sevcon or something else. Seriously my 71 CB 450 feels like it pulls harder.
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If I don't use the zero app there is no top speed. That is it isn't limited by the app.
I can't admit to how fast I may or may not have had the bike ;) I want to take it to a quarter mile track though but I need to prep for winter first. I can always reprogram and strip it down later for that test.
It has a 25 98 gearing right now. It is de-tuned enough not to spin the rear tire when you take off on the line but I have seen the bike do it before it was sent to me.
As for chdfarl's question are you comparing it in sport mode? Was it a SR or S ? The SR is going to throw more amps down range. That said if I recall the amps are capped bellow the max of the size 6 controller. On my bike it isn't capped if I recall.
I will know more when I get my IXXAT in the mail and open up the settings.
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I can't admit to how fast I may or may not have had the bike ;) I want to take it to a quarter mile track though but I need to prep for winter first. I can always reprogram and strip it down later for that test.
Why cant you admit it, your secrets safe with us ;)
It has a 25 98 gearing right now. It is de-tuned enough not to spin the rear tire when you take off on the line but I have seen the bike do it before it was sent to me.
Sounds like fun!
As for chdfarl's question are you comparing it in sport mode? Was it a SR or S ? The SR is going to throw more amps down range. That said if I recall the amps are capped bellow the max of the size 6 controller. On my bike it isn't capped if I recall.
My question was in general towards both the Zero S and Brammo since I rode them both and they were a bit disappointing in that respect. I had expected that if you cranked on the throttle that the front end would at least lighten. The Empulse wasn't bad it did pull way harder than the Zero and I never put the Empulse in sport mode (too busy messing with the camera) but the Zero was in sport buy time the camera was on. The Brammo salesman said that the sport mode wasn't that different though only the regen was different. Now it my understanding that they both use a sevcon and was wondering if it is the throttle mapping taming the torque delivery but your post seems to address that. Id love to compare the SR but couldn't find one even after traveling over 1000 miles to Florida to ride those two bikes.
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Torque curves, as well as torque values can be adjusted in the sevcon controllers. From what I have been told stock bikes are intentionally detunned. Your best bet at feeling the full potential would be to find someone who has set theirs up for racing and has spent the time modifying the sevcon programming.
Then if you decided to go the route of upgrading your programming you would have to get a copy of their's and upload it onto yours via DVT software used to interface with the sevcon controllers.
But realize you might experience overheating issues if you do not ventilate the motor for example. I am not aware of anyone who has upgraded the programming on a SR yet but I do know Electric Cowboy won several events with it stock. You can bet when he starts racing again after setting some records with the stock 2015 he will modify the programming if he can.
I won't admit on a public form to anything my state might be able to use against me in a court of law ;) On another note the speed is off on the speedo by +3 and the miles driven are off as well. If I go ~27 miles it reads 29 miles. I suspect this is because of the gearing.
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To answer your question, yes the throttle is mapped so you don't get as much torque off the line so people don't spin their tires or do a wheelie.
Also, try out a Zero SR. They are awesome. Good punch off the line (still mapped down a bit for safety), but once you hit 30mph the acceleration really rips!
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To answer your question, yes the throttle is mapped so you don't get as much torque off the line so people don't spin their tires or do a wheelie.
Also, try out a Zero SR. They are awesome. Good punch off the line (still mapped down a bit for safety), but once you hit 30mph the acceleration really rips!
Id love to but the East Coast is devoid of electric sales. I plan to check out the International Motorcycle Show in NYC and might check out the Zero dealer in Brooklyn but its in Dec. and the city so riding would be compromised a bit. :'(
Its no wonder motorcyclist are slow to adapt if the companies are detuning there bikes even in sport mode. I know that would squeeze the batteries like a tube of toothpaste (watch my Brammo video) but that wouldn't bother me if the bike was ripping. Id rather play hard for a half hour than putt around for a couple hours. That's only my opinion though and for my money id buy the FX but id still sooner put the battery and motor on my KX chassis.
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Is Cowboy the guy that raced pikes peak and did he race in emoto. I didn't see any or many Zeros mentioned.
http://en.wikipedia.org/wiki/Brandon_Nozaki_Miller (http://en.wikipedia.org/wiki/Brandon_Nozaki_Miller)
The year he was there several Zero's were racing if I recall. There is a video somewhere showing him pealing some tire off the line ;)
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OH I saw a Zero promo video of him talking on their website.
Ive only seen this Zero at the 2013 Daytona finale but that was likely that Johnson guy.
Where is that video id like to see it!
I plan to go to one of the races next year at least if they go to NJ. Id love to race but don't have the money to buy or build a proper eracer and entry fees and travel!
This is the only Brandon Miller Zero video that ive found.
https://www.youtube.com/watch?v=XQ1EnbK5oxU (https://www.youtube.com/watch?v=XQ1EnbK5oxU)
Opps found that one after posting the last.
https://www.youtube.com/watch?v=dKIoPU6708I (https://www.youtube.com/watch?v=dKIoPU6708I)
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Its no wonder motorcyclist are slow to adapt if the companies are detuning there bikes even in sport mode. I know that would squeeze the batteries like a tube of toothpaste (watch my Brammo video) but that wouldn't bother me if the bike was ripping.
It's not just to get more range that they don't allow full thrust instantaneously. There's a wheelspin issue, especially since they don't equip even the SR with wide, sticky tires, which could be a liability issue, especially in wet conditions.
There's a belt-snapping issue; I'm pretty convinced that if the belt can stand 106 ft-lbs of torque, it can stand it at any time, but there is the possibility of high jerk loading causing the belt to have issues (jerk is the mathematical derivative of acceleration; look it up).
But I think the most important issue is just rider familiarity, especially for a new electric rider. The amount of torque the SR (or Burton's bike) gives you is pretty astonishing, and it would be more so if they delivered it instantaneously. People just aren't used to the hammer dropping that fast, and could easily wheelie the bike out from under themselves or just lose control completely, so again it's a liability issue.
I've thought many times that I need to get my bike up to Harlan to have him get rid of any startup slack; I've been riding my SR long enough to respect its immediate power delivery, and it would be nice to see what it can do totally unleashed, a la Burton's bike. Haven't done it yet but I will someday.
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Well as a motorcyclist that spent the time learning to ride and to be safe in the face of such dangers as clutch slip and "whisky throttle" I find that to be a weak rationalization. So they are selling a product to entry level motorcyclists so that they'll never learn proper throttle modulation. I was less disappointed when it seemed like there was no potential to wheelie. Now due to the fact that entry level riders cant handle it you've got to buy a $900 DVT system and likely a chain and sprocket to unleash your $15000 bike that is marketed to have such performance.
I know a lot of you might find my opinion too harsh or narrow minded but I am confident a large number of motorcyclist would say the same and that's not ignorance its experience.
The Empulses 180 rear could handle 66ft-lbs even a 160 or even a good 150 would be sufficient. Now the SR if it actually puts out 106ft-lbs it could use the 180. Like I said don't blame motorcyclist if they don't line up to buy detuned 500-650 twin equivalent bikes. Or don't market torque that's locked in a box.
Have those bikes ever been dynoed by any independent party.
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Don't get me wrong, I'm not trying to defend anything Zero's done. I'm trying to understand it myself. In my mind, there ought to be SOME mode where the motor can put out FULL POWER, by which I mean as much as is safe, without damaging the battery pack (too fast of a discharge rate), the controller or the motor. I was very disappointed to find out that even in "Sport" mode there were arbitrary limits placed on the performance of the bike.
That said, if you've never ridden an SR, you really should quit talking about it being no better than a middleweight ICE bike. Honestly, you're sounding kinda silly to those of us who have ridden one. The actual numbers for the 2014 SR are 106 ft-lbs of torque, 407 pounds weight (without extras like the power tank). A Suzuki Hayabusa puts out 100 ft-lbs and weighs around 500 pounds dry. Even de-tuned, the SR will do 0-60 in an honest 3.3 seconds; that's just 0.1 seconds slower than a Mclaren F1. It's a QUICK machine, though its top speed isn't exceptional. If you're looking to put up top speed numbers way in excess of the ton, this isn't your bike. If you're looking for a ridiculously cheap-to-run and fun general-purpose machine that can embarrass Ferrari drivers, it's hard to do better than a Zero SR.
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Don't call me silly if you cant read my post correctly. I've specifically said that I haven't ridden the SR nor did I criticize it in any way. I said 106ft-lbs is ridiculous amounts of torque and that id love to try one.
I'm not singling out Zero either. My experience with both the Zero S (see I said S not SR) and Brammo Empulse (no not the R) in regards to what I've mentioned were similar so they likely both use a similar approach so no one has to wave any flags. Furthermore I am a huge fan of electric propulsion over gas even as a mechanic and long time Ice motorcyclist. That is actually why my feelings are strong on this subject. Id like to see motorcycle enthusiasts that aren't newbs see everything the bikes can do without the bar being set for new riders.
One last thing Im not looking to fight with anyone over someone else's product or my opinions on it so lets leave as I've stated my point and you yours.
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I don't even think were disagreeing about anything significant.
But I did NOT misinterpret what you said, nor put words in your mouth. Twice, you compared electric bikes to "500-650 twin equivalent bikes". Even to stress a point, you need to stop doing that. These are bikes that ask no quarter and offer none. I don't primarily see them (even the SR) as performance bikes...I think of my SR as the king of commuter machines that just happens to accelerate harder than almost anything with four wheels. But I've seen many comparisons in the mainstream press of the SR to a middleweight bike just because of its horsepower number; that's just plain ignorant of all the issues involved, and we in our community should not be encouraging it. A Honda Hawk this is NOT.
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Perhaps that's the way you see it but they are motorcycles by all definitions and I can certainly compare them based on my experiences and its a fair comparison that even the companies or at least Brammo has mentioned. My only issue was the "detuning".
You are misquoting and misinterpreting me and that is pretty significant! The two bikes that I rode (Zero S and Brammo Empulse) performed in the physical world (under my own ass that has ridden on countless motorcycles) like 250cc ICE bikes and I am confident that they have the potential to feel even greater with a loss of the "new rider" limitations. I'm happy that you like your bike and no doubt id like the SR too but Im not discussing it so you don't have to get all defensive of it. They are likely great city commuters as is typically stated but I'm not discussing that either. And lastly who are you to say what "we in our community" should or shouldn't say!
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You are misquoting and misinterpreting me and that is pretty significant!
Yeah, no, I'm not. You actually posted those EXACT words...it's a direct quote, which is why I used the "quotation marks", There's no possibility of misquoting or misinterpreting when I copied and pasted YOUR OWN WORDS.
I'm happy that you like your bike and no doubt id like the SR too but Im not discussing it so you don't have to get all defensive of it.
I'm not defensive in the least, and I have no problem with you comparing numbers between any bikes. Knock yourself out! That's what this forum is FOR. Let's knock the walls down. Yes, I love my bike. And every mile I ridde, I know that compared to any vehicle around me, 1) I'm spending much less money in the long run, 2) I've got much more performance at my fingertips, and 3) I can smoke you, period, end of sentence. If you ride a Hayabusa, I got you. If you drive a Ferrari, I got you. if you drive a....well, I got you, with no exceptions I'm going to run across, unless you drive a 4WD Tesla or a Mclaren F1 or better. There's not much ground left, let alone ground claimed by vehicles costing less than $100,000.
Look...buy the vehicle you want, based on how well it meets your needs/wants. Just don't deceive yourself about those needs/wants, or how well some vehicle meets them.
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I've thought many times that I need to get my bike up to Harlan to have him get rid of any startup slack; I've been riding my SR long enough to respect its immediate power delivery, and it would be nice to see what it can do totally unleashed, a la Burton's bike. Haven't done it yet but I will someday.
My bike has some slack put back in it from where EC had it set. He said he was either going full throttle or braking so the slack isn't needed.
The SR would be a great beginner bike. We are all forgetting about the zero app and the ability to set the bike up for 0% torque. I ride into work with this setting and it is great for commuting and wont kill you if you abuse the throttle even by mistake. A new rider could slowly turn this up over time to get use to a "bigger" bike.
As for the DVT costing $900 your better off taking it to a dealer and getting it tuned. Unless you plan on making experimental circuits for your bike then you likely wouldn't need it. Or get a group of people who will "share" the DVT and set down some rules for who gets to use it when. Anything you do with DVT could temporarily brick your bike so you would have to make sure to have a backup of your current settings.
Found the wheel spin video of Brandon going up pikes peak on my bike. It is quiet but you can hear it if you listen closely
https://www.facebook.com/video.php?v=643182679045035&set=vb.100000599251363&type=2&theater# (https://www.facebook.com/video.php?v=643182679045035&set=vb.100000599251363&type=2&theater#) Press the HD button ;)
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@Doug S you misquoted me by saying that I in any way referred to the SR other than Id like to ride one. I stand by my comparisons of the bikes I've ridden and am done with this debate! By the way I don't like the hayabusa either :-X
The SR would be a great beginner bike. We are all forgetting about the zero app and the ability to set the bike up for 0% torque. I ride into work with this setting and it is great for commuting and wont kill you if you abuse the throttle even by mistake. A new rider could slowly turn this up over time to get use to a "bigger" bike.
Thanks Burton I didn't have the luxury of playing with the app so I did not know that it was that customizable. And so you guys know even though I do like wheelies that's not what I was looking for only throttle response that reflects throttle input and the bikes that I rode were lacking that in my opinion and experience.
As for the DVT costing $900 your better off taking it to a dealer and getting it tuned. Unless you plan on making experimental circuits for your bike then you likely wouldn't need it. Or get a group of people who will "share" the DVT and set down some rules for who gets to use it when. Anything you do with DVT could temporarily brick your bike so you would have to make sure to have a backup of your current settings.
If I were to buy one then I couldn't or wouldn't be carting it to the dealer since the nearest Zero dealer is in NH and they really didn't seem up on the technology and the nearest Brammo sales is in PA. I would likely try to learn the programing side of it anyway since that's what I do with my ICE bikes and once you learn you know.
Found the wheel spin video of Brandon going up pikes peak on my bike. It is quiet but you can hear it if you listen closely
https://www.facebook.com/video.php?v=643182679045035&set=vb.100000599251363&type=2&theater# (https://www.facebook.com/video.php?v=643182679045035&set=vb.100000599251363&type=2&theater#) Press the HD button ;)
Cool, see wheel spin isn't that scary if you know what your doing! ;D
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Im not convinced they are detuned. AC motors just aren't cable of very high outputs at very low rpm, in the same way that brushed DC motors are.
Also remember that Power is Torque x RPM. At very low RPM you might have 106lb fts of torque but not very much power.
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Im not convinced they are detuned. AC motors just aren't cable of very high outputs at very low rpm, in the same way that brushed DC motors are.
Also remember that Power is Torque x RPM. At very low RPM you might have 106lb fts of torque but not very much power.
I'm an EE, but electric motors really aren't my thing and I struggle to get my head around all the ins and outs of the various configurations...not to mention the nomenclature, which seems confusing and sometimes inaccurate. But my (admittedly incomplete) understanding is that an "AC" motor is intended to run on a fixed line frequency (60Hz here in the States, 50Hz in Japan, etc.) and at a fixed voltage (115VAC or whatever). This is the motor in your refrigerator, your washing machine, etc. It MAY use permanent magnets, but field coils are generally cheaper so are more common in this kind of motor. This motor doesn't like running on any other voltage (high or low voltages may burn it out) or any other frequency (ditto). You're right about THIS motor having very little torque at low RPM; until it winds up to full speed, it's just not operating very efficiently. There are clever controllers available which can get variable speeds out of this type of motor, but no amount of smart electronics can compensate for the motor's inherent lack of torque at low RPM.
A coil of wire with a current passing through it becomes an electromagnet. If you place it near a permanent magnet, it will attract or repel the magnet, depending on which direction the current is flowing, which determines the orientation of the magnetic field it creates. This works at any frequency, from DC (which is 0 Hz) all the way up to the frequency at which the coil of wire doesn't have enough time to build up any field, due to an electrical property referred to as its inductance. If you glue a few permanent magnets to a shaft, then place some coils around them, you can drive the coils in the right sequence to attract and repel the magnets in an alternating fashion, driving the shaft that they're attached to. To me, this configuration is a "brushless DC" motor, although I'm told that's not quite the correct terminology; it's "brushless" in the sense that brushes are not needed to energize field coils on the rotor because there ARE no field coils (permanent magnets instead); it's a "DC" motor because it works just fine all the way down to 0 RPM. This is the configuration that Zero uses, and in addition to providing full torque at zero speed, it's easy to cool the coils because they're on the outside of the motor rather than the inside.
Sorry for the rather long-winded explanation, but I find that trying to explain things to someone else usually helps my own understanding. Hopefully I didn't screw up too much in my story.
Oh, and you're right about the relationship between torque and power. In common units, horsepower equals torque (in ft-lbs) times RPM divided by 5250, if memory serves. When talking about vehicle performance, you're almost invariably going to be torque-limited at low speeds and power-limited at high speeds, with some transition speed where the torque and power limits are equal.
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Just to add to the conversation, power (as mentioned) is what does work (and moves you along). So torque without rpm isn't going to move you. You need torque and rpm to produce power which results in movement, acceleration and then velocity. You don't need to spin up an electric motor to 10K rpm with the clutch out, then slip the clutch to prevent stalling, as you do with an IC motorcycle, but at low speed it still takes a while to get moving quickly on an EV.
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I should have used the term PMAC but I have heard that and brushless DC used interchangeably.
If you ride an old Zero X with an Agni brushed motor the kick from zero mph is quite impressive even with the relatively low power output compared to the Motenergy and z force motors. Brushed motors will always be more responsive. I believe due to the time it takes to energise the field coils in a PMAC/BLDC motor.
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I have to say I agree the old zero x still have quite a kick for how small they are but the stock 13 fx bike throttle response power delivery is a million miles ahead even with one battery. A hotroded fx turns into a complete monster mine was tuned to edge out a Ducati monster 0 to 70 so decently quick for a dirt bike/now motard
I have raced a few 600 street bikes and I can get out ahead
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I should have used the term PMAC but I have heard that and brushless DC used interchangeably.
A great example of why the nomenclature drives me crazy.
Brushed motors will always be more responsive. I believe due to the time it takes to energise the field coils in a PMAC/BLDC motor.
I don't think that's correct. The coils on a brushed DC motor have to be "commutated" (the current periodically reversed through them) as well. They just accomplish it with brushes rather than smart electronics. In truth, transistors are far faster than any mechanical contact could ever be, and don't exhibit sparking or wear, and have lower losses to boot.
I'm sure there are other differences that account for the different feel you've experienced...probably just the way the motor is designed. Even after they've settled on a configuration (PMAC, say) they still have a lot of design decisions left -- wire gauge, number of turns per coil, number of north/south poles (magnets on the rotor, number of coils), etc. All of those decisions give the designer considerable flexibility to design a high-torque-at-low-rpm motor vs. a high-power-at-high-speed motor, optimize efficiency at some set of conditions, whatever they're looking for. Even if you're not designing from scratch, so many motors are available on the open market you can have pretty much whatever you wish. I'm sure the designers of the bikes we ride have made and changed many decisions about how their motors should perform over the years.
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Don't get me wrong, I'm not trying to defend anything Zero's done. I'm trying to understand it myself. In my mind, there ought to be SOME mode where the motor can put out FULL POWER, by which I mean as much as is safe, without damaging the battery pack (too fast of a discharge rate), the controller or the motor. I was very disappointed to find out that even in "Sport" mode there were arbitrary limits placed on the performance of the bike.
I can say with a great deal of confidence that Sport mode gives you all the power/torque possible that the battery/motor/contrller can provide when you go wide open throttle at any point on a Zero.
If you have time, read through this article (and the lengthy comment)
http://evmc2.wordpress.com/2014/07/07/motor-starting-torque-stall-torque-and-motor-types/ (http://evmc2.wordpress.com/2014/07/07/motor-starting-torque-stall-torque-and-motor-types/)
-ryan
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I think I said it on page one but has anyone had their bike on a dyno that has rear wheel numbers and a graph. Any discussion cant be substantiated without that and so its only calculation and or subjective speculation.
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Chdfarl, I seem to recall that a couple of the monthly motorcycle magazines performed dyno tests on the 2013 "S" last year and got almost exactly the torque and power that Zero claimed. I think that most of the dyno action happened after 1000 rpm.
I did find this dyno comparison graph in my computer files. I am not quite sure why I gave it the title as it seems to compare 2012 and earlier models. Also I have no recollection where the graph originated. ???
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Thanks Richard230 what magazines did you see dyno graphs in. That one that you posted doesn't look like any chassis dyno chart I've even seen though.
I only found this
https://www.youtube.com/watch?v=7xKqb36JGmI (https://www.youtube.com/watch?v=7xKqb36JGmI)
http://www.cycleworld.com/wp-content/uploads/2012/05/Zero-S-HP-TQ-dyno-chart.jpg (http://www.cycleworld.com/wp-content/uploads/2012/05/Zero-S-HP-TQ-dyno-chart.jpg)
http://www.motorcycle.com/gallery/gallery.php/d/325660-2/2012-zero-ds-vs-2010-zero-s.jpg?g2_GALLERYSID=TMP_SESSION_ID_DI_NOISSES_PMT (http://www.motorcycle.com/gallery/gallery.php/d/325660-2/2012-zero-ds-vs-2010-zero-s.jpg?g2_GALLERYSID=TMP_SESSION_ID_DI_NOISSES_PMT)
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It's not just to get more range that they don't allow full thrust instantaneously. There's a wheelspin issue, especially since they don't equip even the SR with wide, sticky tires, which could be a liability issue, especially in wet conditions.
There's a belt-snapping issue; I'm pretty convinced that if the belt can stand 106 ft-lbs of torque, it can stand it at any time, but there is the possibility of high jerk loading causing the belt to have issues (jerk is the mathematical derivative of acceleration; look it up).
Thanks for the links above, I just want to say more than a few people have missed the point of that thread. As a builder I'm concerned with the various trade-offs of the types of motors you can run, and it seemed to my butt that all of the AC/brushless motors have less of a feel of a jolt right off the line than the PMDC motors I've run. It's pretty clear that every motor type and design has slightly different "stall torque" characteristics. That's basic motor design and physics, as I learned. And it's backed up by the graphs.
Softer stall torque in a PMAC motor I'd say even applies to the Energica EGO I rode. Peg the throttle off the line, and it feels soft (and no, I couldn't pull the front end up or spin the tire even though I tried, but it gets 0-60 in under 3 sec.). Once it spins up, it's all hell breaking loose. The Zero SR I rode is what got my attention on this issue, because it was so quick 0-60, but my PMDC would lift the front end where the Zero SR won't.
Regarding the quote above, I can't imagine wheelspin being an issue under any normal riding conditions for a bike like this. Nor is belt-snapping. The only bikes I've ever ridden that spin the wheel as opposed to lifting the front end are heavy pigs - Harleys, Leadwings, etc. Anything that has a decent power to weight ratio will lift the front long, long before it spins the tires. My bike, very similar to the Harley Livewire in all performance specs, and not far off the SR in everything but range, would never spin the tire, though the front end comes up all the time. It's running a very narrow, '70s style width on a 1971 stock lace wheel.
As far as belt-snapping due to off-the-line power application, it ain't gonna happen.
And to be clear, I'm talking about torque from start - that is, 0 RPM to the 500 RPM range. The torque a motor has to start itself spinning, which is not the same as other measurements of torque and power.
I think it's pretty clear (to me, anyway) that first, the characteristics of the Zero motor being what they are, and second, the throttle mapping they've decided on, gives the SR a slightly soft start. That's good for 95% of riders.
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Regarding the quote above, I can't imagine wheelspin being an issue under any normal riding conditions for a bike like this.
As far as belt-snapping due to off-the-line power application, it ain't gonna happen.
I think it's pretty clear (to me, anyway) that first, the characteristics of the Zero motor being what they are, and second, the throttle mapping they've decided on, gives the SR a slightly soft start. That's good for 95% of riders.
I think just about everything you say is spot-on, Ted. I would point out the clip that Burton linked to, which shows Electric Cowboy spinning his rear wheel starting his Pike's Peak run to show that it IS possible for a lean, high-performance bike to do so, but I agree that it's rare without front-wheel braking or dropping the clutch on a spun-up ICE motor. Modern tires are just too good.
I'd also agree that belt snapping isn't much of an issue. If it can withstand 106 ft-lbs of torque, it should be able to withstand it under any circumstances. Belt lifetime could be an issue, but if you break belts early because you're hot-rodding every start, that's on you, not the equipment.
But I disagree with Biff entirely; I respect his belief, but a couple of guys (Burton and DoctorBass, IIRC) have actually seen the code that's loaded into the controller, and it's clear that torque is intentionally limited at very low (near zero) RPM. One of them (I think the good doctor) even posted the code listing, but I can't find it right now. And my experience in over 8000 miles on my SR makes me believe it's true -- the bike is quick off the line, but the torque definitely builds from zero speed up to 20 or 30 mph. One of the other guys also drag-raced an SR against a Brammo, and he said the same thing -- the Brammo kept pace until about that speed, then the SR walked away.
I'm quite certain that Zero has limited the torque output at very low speeds, and I'm just trying to understand why. Okay, belt snapping may not be a major factor, wheelspin may not be big either (except when traction is low due to rain or poor surfaces), so what is the reason? Is it pure overly cautious liability concern? I'm beginning to think it must be.
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The difference of if the front end lifts or traction breaking is typically a riding position issue rather than anything else. Simply put leaned forward or leaned over expect slippage where as if your sitting up and back while riding straight then the time is 12o'clock (term for a straight up and down wheelie).
That's all great info stuff that I never considered until riding those two bikes since everyone touts the 100% from 0 claims. There is one flaw in this theory of the lag being a stall torque issue. That is even when accelerating out of a corner at low or high speed the lag was still there. In contrast there are quite a few petrol bikes out there with less torque that lift the wheel in 3rd or 4th gear at up to 90 mph and watch the throttle while exiting a corner if you like your paint and life. Now Ill pause here to say that personally I feel that those practices are foolish and excessive but the point is that 66 ft-lbs on a 400 lb bike isn't limited to lifting from a stop. If you've never ridden a modern sportbike (no not the Hayabusa!) even a 600cc or even a standard bike like an FZ then you might not understand what I mean (that statement is not pointed at any individual!).
By the way that guy is riding the crap out of his clutch https://www.youtube.com/watch?v=R02BcaMw8oo (https://www.youtube.com/watch?v=R02BcaMw8oo) and that guy is totally fumbling the start https://www.youtube.com/watch?v=0ljqeIEUhLo (https://www.youtube.com/watch?v=0ljqeIEUhLo) .
If your happy with the throttle response that's great but don't boast crazy torque if its bottled or limited (this statement is in reference to the Zero S and Brammo Empulse that I rode exclusively!) By the way my street ride is my first bike a 1971 CB 450 (not a fast bike) and I plan on replacing it with a 72V 450A 25HP electric bike with whatever torque is on it for the street. Im content with that but you wont hear me saying that its out pacing even a moped (no im not comparing any production electric motorcycle to a moped!) if its not.
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Thanks Richard230 what magazines did you see dyno graphs in. That one that you posted doesn't look like any chassis dyno chart I've even seen though.
I only found this
https://www.youtube.com/watch?v=7xKqb36JGmI (https://www.youtube.com/watch?v=7xKqb36JGmI)
http://www.cycleworld.com/wp-content/uploads/2012/05/Zero-S-HP-TQ-dyno-chart.jpg (http://www.cycleworld.com/wp-content/uploads/2012/05/Zero-S-HP-TQ-dyno-chart.jpg)
http://www.motorcycle.com/gallery/gallery.php/d/325660-2/2012-zero-ds-vs-2010-zero-s.jpg?g2_GALLERYSID=TMP_SESSION_ID_DI_NOISSES_PMT (http://www.motorcycle.com/gallery/gallery.php/d/325660-2/2012-zero-ds-vs-2010-zero-s.jpg?g2_GALLERYSID=TMP_SESSION_ID_DI_NOISSES_PMT)
I found it. :) Motorcycle Consumer News performed a complete instrumented road test of the ZF 11.4 SR with power tank (14.2 kWh), including a dyno run, in their September 2014 issue. The dyno chart starts at 1000 rpm and the motor drops dead at 6K rpm. Torque starts at about 106 lb. ft. at 1K rpm and then bumps up slightly to 109 lb. ft at 3.400 rpm, when it starts dropping quickly to about 60 lb. ft. at 5,600 rpm and hits zero at 6K. Power grows from 20 hp at 1K rpm to 72.8 hp at 3,800 rpm. Power slowly drops off to about 62 hp at 5,600 rpm and drops like a rock to 6K rpm.
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CRAP! cant see it online! Sounds cool though but why not until 1000RPM is that the bike or the dyno not picking it up
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CRAP! cant see it online! Sounds cool though but why not until 1000RPM is that the bike or the dyno not picking it up
I have no idea, but it must have something to do with the type of dyno. It might be a rolling inertial drum type and perhaps those devices must be revolving before they can provide any power and torque results. ???
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"Sounds cool though but why not until 1000RPM is that the bike or the dyno not picking it up"
Not sure, but I would hazard a guess that some dyno's are probably not set up / calibrated to record anything under the idle speed of an ICE engine perhaps?
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CRAP! cant see it online! Sounds cool though but why not until 1000RPM is that the bike or the dyno not picking it up
Agreed, I'd love to see that graph. Can you digitize it for us, Richard? Just take a digital pic and post it, that'd make me happy. If the magazine won't do it, someone should pick up the slack for them.
I imagine Justin's right, their dyno's just set up to start the run at 1000 RPM. That's not a bad number to start with for an ICE bike but it's a lousy starting point for an electric. It skips the most interesting region entirely. Too bad they didn't invest a little time/energy into setting up a better test...but I'd still love to see it!
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http://www.motorcycleconsumernews-digitalmagazine.com/mcnews/september_2014d?pg=20#pg20 (http://www.motorcycleconsumernews-digitalmagazine.com/mcnews/september_2014d?pg=20#pg20)
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There is one flaw in this theory of the lag being a stall torque issue. That is even when accelerating out of a corner at low or high speed the lag was still there.
Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
I didn't really realize that myself until I was losing my balance at almost 0 mph, falling backwards, and twisting the throttle as I fell. I instinctively grabbed for the clutch, which of course wasn't there.
...the clip that Burton linked to, which shows Electric Cowboy spinning his rear wheel starting his Pike's Peak run ...
Not to be pedantic, but I consider chirping the rear on a start to be quite a bit different than "wheel spin" for whatever that's worth.
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http://www.motorcycleconsumernews-digitalmagazine.com/mcnews/september_2014d?pg=20#pg20 (http://www.motorcycleconsumernews-digitalmagazine.com/mcnews/september_2014d?pg=20#pg20)
Thanks for digging that up, Justin! The article is just as good a read as it is nice to see actual dyno test results.
I love the articles that clearly come from skeptical minds. These days, in the end they always wind up converted, yet offer up a few standard caveats: 1) They're expensive (very valid argument), 2) range limitations (valid argument, but not very weighty these days), 3) recharging times (ditto), 4) sub-standard hardware (ditto again), and 5) they're too quiet to be safe (come on! -- studies buried that old trope years ago). But at the very, very end, their skepticism lifts fractionally and it becomes clear....they want one.
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Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
I wasn't saying that stall torque was a theory in and of it self but rather a theory as to the Zeros acceleration "lag" and the mapping was confirmed on page 1 but stall torque was brought up so that's why I commented there.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
If you read back that was discussed one page 1 too where I argued that catering to new riders could alienate experience riders that would like to see the full potential of the bikes (Zero S and Brammo Empulse some how the SR became the subject) other motorcycle companies have TC traction control that could be turned off.
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Yes, as I said, just clarifying.
About the clutch, I'm not sure that that point was actually made - in fact I've not seen it discussed anywhere, regarding the clutch giving you an emergency disengage in a "clutch" situation (oh, gawd, sorry). ::)
Unfortunately it's something most riders don't learn until they experience it. Also it's something that more experienced riders will struggle more with than newbies, since it's all muscle memory. Riding my dirt bike, (converted RM125) it's practically something I have to talk to myself out loud, since so much of that is slow-speed stuff. I also have a hard time riding scooters, where the front brake is on the left hand. I'm always grabbing for the clutch, (which I don't need because it's an automatic) and grabbing a handful of front brake instead.
Kind of still on topic, I guess, in a remote way. Moving on... :D
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I feel the topic is all encompassing.
Ive been trying to design an emergency drive disconnect for direct drives like the Zeros but don't know the shaft size yet.
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To answer your question, yes the throttle is mapped so you don't get as much torque off the line so people don't spin their tires or do a wheelie.
Also, try out a Zero SR. They are awesome. Good punch off the line (still mapped down a bit for safety), but once you hit 30mph the acceleration really rips!
Id love to but the East Coast is devoid of electric sales. I plan to check out the International Motorcycle Show in NYC and might check out the Zero dealer in Brooklyn but its in Dec. and the city so riding would be compromised a bit. :'(
Its no wonder motorcyclist are slow to adapt if the companies are detuning there bikes even in sport mode. I know that would squeeze the batteries like a tube of toothpaste (watch my Brammo video) but that wouldn't bother me if the bike was ripping. Id rather play hard for a half hour than putt around for a couple hours. That's only my opinion though and for my money id buy the FX but id still sooner put the battery and motor on my KX chassis.
http://www.zeromotorcycles.com/locator/ (http://www.zeromotorcycles.com/locator/)
Carbon- (Brooklyn) and the one in Albany dropped off the Zero Dealer Locator.
I was able to call C- on the phone as recently as last month, but the situation may have changed recently.
I'm still trying to hunt down what happened and what my options are. It seems like it can't be a permanent situation that the largest metro area of the country has no dealer.
The nearest dealer on the locator now appears to be Cherry Hill, NJ, just outside of Philadelphia.
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Not to be pedantic, but I consider chirping the rear on a start to be quite a bit different than "wheel spin" for whatever that's worth.
I can't agree with you there. Once a tire's broken loose, it's a lot harder to regain traction. The drag racers work very hard to not chirp their tires on launch because the know if they do, they're just a razor's edge away from going up in smoke.
But I'm not saying EC "spun his tire". I'm saying it's very possible, and as someone else said, it's probably more of a matter of weight distribution, wheelbase, etc. than it is any lack of power/torque. Electrics are just as capable of spinning their rear tire as ICE bikes are.
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Carbon- (Brooklyn) and the one in Albany dropped off the Zero Dealer Locator.
I was able to call C- on the phone as recently as last month, but the situation may have changed recently.
I'm still trying to hunt down what happened and what my options are. It seems like it can't be a permanent situation that the largest metro area of the country has no dealer.
The nearest dealer on the locator now appears to be Cherry Hill, NJ, just outside of Philadelphia.
Dynomutt that info is greatly appreciated. Benswing was nice enough to PM me that fact the other day but that end of NJ is very far to go from the Boston area in the winter. Great Bay Motorcycles is closer to me in NH only 21/2 hrs that's where I rode the FX (awesome bike) but there S was an older version. It looked like a 2012 but I hardly looked at it since time was short and the FX was cooler.
I can't agree with you there. Once a tire's broken loose, it's a lot harder to regain traction. The drag racers work very hard to not chirp their tires on launch because the know if they do, they're just a razor's edge away from going up in smoke.
That's not quite accurate once you lose traction with wheel spin its as simple as decreasing the throttle ( usually ) and grip comes back ( check out some super moto/motard drift videos ). That is why in drag racing you try not to spin since they can usually balance the bike while spinning the tire but they aren't hooking up so they don't go fast or far until they back off and that's the skill in launching and throttle modulation and that's why in my opinion TC is cheating. :-[
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@teddillard I was talking to a friend who has ridden a lot of bikes a mechanic and they were interested in riding the zero and noticed it had no clutch either. I informed them all they had to do was roll off the throttle :/
To me it wasn't difficult to transition to this while still riding my ICE bike where I keep my controls covered. In my mind they just are different and operate differently.
As for adding a fake clutch you could slave your kill switch to a clutch lever and go that route. I plan on using my clutch lever for dynamic regeneration though. Or go with two clutch levers and cover the kill switch one? ;) Or maybe have the regen lever trip the kill switch when it bottoms out (this would be some neat engineering to accomplish)
I have had two emergency stop scenarios with my zero so far. Both times without thinking I simply rolled off the throttle and engaged the front brake at the same time ... I think. I keep my front brake covered at all times so it happened really fast. I haven't tried to activate the brake light while the throttle was so open I couldn't not still have it open when applying the brakes yet. What is programmed to happen in this case?
I can think of two times in my 46k miles on my ICE bike where when emergency stopping my motor rev'ed pretty high because I simply clutched in / braked really fast and didn't drop the throttle down.
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@Burton the emergency disconnect would be for a situation where say the motor somehow locked up while riding with a seized bearing or meltdowm. Shutting off the killswitch wont free the rear wheel and if it locks then the bike would slide. I remember it happening at the TTXGP one year there was a crash on youtube.
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Little confused. The brake light comes on even if you are doing a massive rolling burnout and holding the front bake slowly releasing so thoes wild drift/sliding launches
Personally after having talked to a friend more and more about variable progressive braking I'll pass; seems like it will cause problems in the long term to the bike (from what I have been told)
I think best option is just tune the regen better like on my other retuned bike.
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@Burton the emergency disconnect would be for a situation where say the motor somehow locked up while riding with a seized bearing or meltdowm. Shutting off the killswitch wont free the rear wheel and if it locks then the bike would slide. I remember it happening at the TTXGP one year there was a crash on youtube.
If I had a massive seize and had to walk the bike home after I'd just slip the belt off the rear or worst case snip it.... If you truly did have a lockup I think the bike would be the least of your issues, if be happy if I could walk away from a lock up rear crash at speed prolly care less about the bike at that point
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If I had a massive seize and had to walk the bike home after I'd just slip the belt off the rear or worst case snip it.... If you truly did have a lockup I think the bike would be the least of your issues, if be happy if I could walk away from a lock up rear crash at speed prolly care less about the bike at that point
That's the whole point if the motor seized then you pull this disconnect and you don't lock up long enough to crash. Its a split second reaction but if you cant manage that then you probably shouldn't ride a motorcycle ( not directed at you personally but if you fit the description its not an insult only an honest point that motorcyclist should be prepared for disaster )
Same thing with the motard slide. On exit they typically use throttled wheel spin to turn the bike. How this applies to street riding is if you accidentally loose traction with an over zealous twist then you can SLOWLY back off until you feel traction at the tire.
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Personally after having talked to a friend more and more about variable progressive braking I'll pass; seems like it will cause problems in the long term to the bike (from what I have been told)
What is this variable progressive braking you speak of?
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@Burton the emergency disconnect would be for a situation where say the motor somehow locked up while riding with a seized bearing or meltdowm. Shutting off the killswitch wont free the rear wheel and if it locks then the bike would slide. I remember it happening at the TTXGP one year there was a crash on youtube.
Can you find the TTXGP crash and show specifically where it was a bearing failure of the motor? I am sure there must have been a huge write up about this somewhere. That stated I am not racing my bike but it does have ceramic bearings in the motor.
If this was really a problem I am sure it wouldn't be hard to engineer a guillotine device to cut the belt. A CO2 cartridge driven device could do this easily I would imagine. Just be sure not accidentally hit the firing device while casually riding lol
I think it might be a very long time before you get a clutch like device on these motors given the amount of torque they push out. Are there any electric bikes with operable clutches where they perform better or identical to Zero bikes for example?
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Carbon- (Brooklyn) and the one in Albany dropped off the Zero Dealer Locator.
I was able to call C- on the phone as recently as last month, but the situation may have changed recently.
I'm still trying to hunt down what happened and what my options are. It seems like it can't be a permanent situation that the largest metro area of the country has no dealer.
The nearest dealer on the locator now appears to be Cherry Hill, NJ, just outside of Philadelphia.
Dynomutt that info is greatly appreciated. Benswing was nice enough to PM me that fact the other day but that end of NJ is very far to go from the Boston area in the winter. Great Bay Motorcycles is closer to me in NH only 21/2 hrs that's where I rode the FX (awesome bike) but there S was an older version. It looked like a 2012 but I hardly looked at it since time was short and the FX was cooler.
So, I discovered just today that apparently the space that C- formerly occupied is now in use by a company called "MotorGrrl" (http://www.motorgrrl.com/ (http://www.motorgrrl.com/)) that operated a cooperative mechanical workspace. The person who answered the phone says that they have taken over the operation of the space and that the principals of C- are no longer involved in any way.
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Can you find the TTXGP crash and show specifically where it was a bearing failure of the motor? I am sure there must have been a huge write up about this somewhere. That stated I am not racing my bike but it does have ceramic bearings in the motor.
If this was really a problem I am sure it wouldn't be hard to engineer a guillotine device to cut the belt. A CO2 cartridge driven device could do this easily I would imagine. Just be sure not accidentally hit the firing device while casually riding lol
I think it might be a very long time before you get a clutch like device on these motors given the amount of torque they push out. Are there any electric bikes with operable clutches where they perform better or identical to Zero bikes for example?
I'm going to list a few things here to address this rather than a lengthy confusing paragraph.
I AM NOT SAYING NOR DID I EVER SAY TO USE A CLUTCH ON ANY ELECTRIC MOTORCYCLE! WHAT I SAID WAS DISCONNECT!
If you doubt that the bearing or motor could lock up then may it never happen to you but I wont feel bad for you either. Racing or not machines ( even electric ones ) break and the point is to save your ass not mine.
The Ducati Panigale has 100 ft-lbs of torque as do other sportbikes these days so its clutch could handle even the Zero SR ( Oh no I spoke its name :o )
http://www.ducati.com/bikes/superbike/1299_panigale/tech_spec.do (http://www.ducati.com/bikes/superbike/1299_panigale/tech_spec.do)
I was the guy that said that the clutch was of little use even on the Brammo
I don't remember where I saw the video and couldn't find it yet. It was like the second year at the TT ( who knows it could've been a vivid dream )
Even if it never happened do you really feel that such a mechanism threatens or impairs your machine.
You could cut the belt if you like but a disconnect would do it without cutting the belt.
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So, I discovered just today that apparently the space that C- formerly occupied is now in use by a company called "MotorGrrl" (http://www.motorgrrl.com/ (http://www.motorgrrl.com/)) that operated a cooperative mechanical workspace. The person who answered the phone says that they have taken over the operation of the space and that the principals of C- are no longer involved in any way.
I heard the guy was building his own electric bicycles or something like that. It is disappointing that there isn't any electric motorcycle sales in New York City.
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I AM NOT SAYING NOR DID I EVER SAY TO USE A CLUTCH ON ANY ELECTRIC MOTORCYCLE! WHAT I SAID WAS DISCONNECT!
Do you have an example of a mechanical disconnect which is not a clutch based device that could be retrofitted onto electric bikes?
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No and I wouldn't post my design yet but its quite simple yet rugged but wouldn't fit in the small space on the Zero at the sprocket but a belt tensioner with a quick release would.
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Over sized belt, with adjustable tensioner which could be spring loaded to a quick release seems like it would work ... Wonder what size belt would be needed and if they are easy to find. It would also introduce another point of failure though so it would indeed have to be pretty rugged.
Would you constantly cover said control or only keep it in fingers reach?
I can think of several ways of making such a device but I likely wouldn't have to time to do it any time soon given all the other projects I am working on.
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But I disagree with Biff entirely; I respect his belief, but a couple of guys (Burton and DoctorBass, IIRC) have actually seen the code that's loaded into the controller, and it's clear that torque is intentionally limited at very low (near zero) RPM. One of them (I think the good doctor) even posted the code listing, but I can't find it right now. And my experience in over 8000 miles on my SR makes me believe it's true -- the bike is quick off the line, but the torque definitely builds from zero speed up to 20 or 30 mph. One of the other guys also drag-raced an SR against a Brammo, and he said the same thing -- the Brammo kept pace until about that speed, then the SR walked away.
I'm quite certain that Zero has limited the torque output at very low speeds, and I'm just trying to understand why. Okay, belt snapping may not be a major factor, wheelspin may not be big either (except when traction is low due to rain or poor surfaces), so what is the reason? Is it pure overly cautious liability concern? I'm beginning to think it must be.
That is one common misconception that I would really like to clear up. There is no firmware based modification that anyone has done to any brushless Zero motorcycle that has increased the torque of the motor, because the configurations that come with the stock vehicle are already set to get as much performance as possible.
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@teddillard I was talking to a friend who has ridden a lot of bikes a mechanic and they were interested in riding the zero and noticed it had no clutch either. I informed them all they had to do was roll off the throttle :/
To me it wasn't difficult to transition to this while still riding my ICE bike where I keep my controls covered. In my mind they just are different and operate differently.
As for adding a fake clutch you could slave your kill switch to a clutch lever and go that route. I plan on using my clutch lever for dynamic regeneration though. Or go with two clutch levers and cover the kill switch one? ;) Or maybe have the regen lever trip the kill switch when it bottoms out (this would be some neat engineering to accomplish)
I have had two emergency stop scenarios with my zero so far. Both times without thinking I simply rolled off the throttle and engaged the front brake at the same time ... I think. I keep my front brake covered at all times so it happened really fast. I haven't tried to activate the brake light while the throttle was so open I couldn't not still have it open when applying the brakes yet. What is programmed to happen in this case?
I can think of two times in my 46k miles on my ICE bike where when emergency stopping my motor rev'ed pretty high because I simply clutched in / braked really fast and didn't drop the throttle down.
You missed the bit about losing my balance. I was falling backwards, and as a result twisting the throttle on. The more I did that, the more the bike walked away, and the more it twisted on. It was a ridiculous slow-speed hilarious thing, except for it kind of hurt. ::) Ultimately your brain kicks in and you just let go of the bike and try to get out of it's way.
It's not an unusual thing to happen at all with dirt riding, especially if you like hill climbs, and it can be how it goes if you're dumping in some slow-speed turns. One guy I knew of had it happen pulling out of a parking lot, turning and leaning, and hitting sand, for example. If you ride long enough (40+ years in my case) you find lots of cool ways to fall over. :D Back in my misspent youth I'd do about half your 46k miles in a summer.
With a gas bike you try to grab the clutch, but sometimes that's not even possible. With an electric, you'd go for the kill switch I suppose, but that's not a reflex that is so ingrained.
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Speaking of bearings failing: Terry was on his way to my home a couple of years ago and while he was crossing the Golden Gate Bridge, the bearings on his 2012 Zero motor decided to throw in the towel at around 20K miles of hard use. My recollection is that the motor didn't lock up, but instead it made some nasty noises and slowly ground to a halt. I don't think the incident resulted in any disruption of traffic on the Bridge, but he did have to have the bike towed to the Zero factory where they replaced the motor and sent him on his way.
I have had a couple of friends over the years have their rear wheel bearings disintegrate. While the bearings made a mess inside the wheel hub, I don't recall anyone complaining about the rear wheel locking up.
So I don't think that the idea that motor bearings might fail and toss you off your bike is something to worry too much about. What you should be worried about is the cost and hassle of replacing the motor if you are out of warranty. :o
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So I don't think that the idea that motor bearings might fail and toss you off your bike is something to worry too much about.
My old boss used to talk about chasing a mouse with a red Ferrari. I think that quote's appropriate here.
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@Ted how'd you get to ride the Ego anyway? ??? That might seem off subject but the tread is concerning test rides.
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Hey, it's your thread... 8)
I've been in touch with the folks at Energica (CRP) for several years now, and was invited to do a test ride/review when they did the big tour this summer. I reviewed it for my site, The Electric Chronicles (more from a builder's standpoint), and also InsideEVs (a more standard review), which I write for now.
links:
http://evmc2.wordpress.com/2014/07/29/the-energica-ego-ride-bike-review/ (http://evmc2.wordpress.com/2014/07/29/the-energica-ego-ride-bike-review/) (my site)
http://insideevs.com/energica-ego-bear-mountain-ride-review/ (http://insideevs.com/energica-ego-bear-mountain-ride-review/) (InsideEVs)
...and the video:
https://www.youtube.com/watch?v=osANHXyhtb8 (https://www.youtube.com/watch?v=osANHXyhtb8)
(Sorry, can't seem to figure out how to embed it here.)
That's Ben(swing) Rich in front of me at the start of the video, by the way. :D
More interesting to me, personally, was the chance to have a lengthy talk with Livia Cevolini. There are no interviews with her online (that I could find) in english, to the point that I wondered if she spoke english well. (She does :D) I did these interviews, but also talked with her for about an hour before that. It was a really remarkable chance to learn a whole lot about the process of designing a machine like this, and bringing a bike to market. Kinda puts the "I'd do it this way..." and "why didn't they..." chatter into perspective.
http://evmc2.wordpress.com/2014/07/29/the-livia-cevolini-interviews-energica-crp-ego-racing-the-market-all-that/ (http://evmc2.wordpress.com/2014/07/29/the-livia-cevolini-interviews-energica-crp-ego-racing-the-market-all-that/)
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Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
Please stop proliferating this rumour, It is not true. Zero does not limit off the line torque. You can hold the rear brake, go full throttle and measure RMS current into the motor and you will see that it is the maximum that the controller will deliver.
Also feel free to install accurate accelerometers on the motorcycle (or accurate wheel speed sensors) to measure acceleration, you will see that it is constant from 0 to around 40mph (at which point wind starts to cause decreased acceleration, and as speed increases the constant power section of the power curve limits acceleration).
Thanks,
-ryan
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Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
Please stop proliferating this rumour, It is not true. Zero does not limit off the line torque. You can hold the rear brake, go full throttle and measure RMS current into the motor and you will see that it is the maximum that the controller will deliver.
Also feel free to install accurate accelerometers on the motorcycle (or accurate wheel speed sensors) to measure acceleration, you will see that it is constant from 0 to around 40mph (at which point wind starts to cause decreased acceleration, and as speed increases the constant power section of the power curve limits acceleration).
Thanks,
-ryan
How do they regulate the power then?
The fx is "limited" 0 to 30
My other which is much less limited sure seems like it has 2x the power from 0 to 30
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Zero does not limit off the line torque.
Seriously then what is it! That S that I rode didn't feel like it had half of the 68 ft-lbs that is advertised. That's not criticism or skepticism. It would be nice if someone who really knows would explain it. My asses accelerometer is very accurate and it read nowhere near 60.
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My experience on all 2012-14 zeros is that the acceleration increases noticeably at 30mph.
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I wouldn't argue that but its 0-30 or even a firm twist after that if the torque was " instant " you wouldn't simply notice it, it would scare the shit out of you. That's not what at least the bikes that I rode ( Brammo Empulse and Zero S ) were like. Though they were quite smooth they had not 60ft-lbs of kick when I cracked the throttle there was lag that you could see 4:40 on the Zero video that's hard twist on the throttle and at 1:20 and 6:10 on the Brammo video. They went but not the way you'd expect. On any other bike with that kind of torque it would be a hard launch the kind that lifts the front wheel but they felt like small ICE bikes to me. Now that's not saying that they suck but it is hard to see where the " instant " torque is. If it was set to be limited, even though I feel that would suck then it would at least explain what felt like a lag. Look at Cortezdtv's video to see what it would look like. Even though his bike is an FX and 100lbs lighter than an S a 400lb bike with that kind of torque would be a handful but it wasn't. The Brammo did accelerate harder and is 60lbs heavier but still felt lacking to me.
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You can believe Biff, he knows what he's writing. The torque is not limited in low rpms, it's set to controller maximum from zero. Look at the red graph in the first picture.(http://tapatalk.imageshack.com/v2/14/11/17/a3313b93d08101925e6d428647fa0af8.jpg)
What you feel as acceleration is simple said torque x rpm - resistances. The more horsepower the more acceleration, simple. Again red graph (http://tapatalk.imageshack.com/v2/14/11/17/8327088631cde7f50a58e2fb7f7976a2.jpg)
I had the same feeling as you guys when riding first electric bikes but it's new situation. Blue graph is with gearbox, it shows low gear with less torque makes more power in low rpms and better of the line speed. For example 30nm x 6000rpm > 90nm x 500rpm. That's need to be understood..
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You can believe Biff, he knows what he's writing.
I don't believe anybody who "knows what he's talking about" but doesn't cite any sources or even say WHY he believes what he believes. Just one more voice in the wilderness until that time.
What you feel as acceleration is simple said torque x rpm - resistances. The more horsepower the more acceleration, simple.
Uh, no. Torque is the rotational analog of force (twisting instead of pushing in a straight line), and no less of a scientist than Sir Isaac Newton tells us that force equals mass times acceleration. Horsepower does NOT cause acceleration, torque does; it's just that simple. Horsepower is the ability to supply energy at a high rate of speed, which is only necessary when losses are high, as at high speed. Numerically, horsepower is equal to torque (in ft-lbs) times rpm divided by 5250. In the real world, there are always losses (what you call "resistances"), which is why torque and horsepower are a bit lower when measured at the rear wheel than when measured at the engine....but in any vehicle, losses are pretty small. In a drivetrain as simple as ours is, losses are near to being negligible.
In the real world, a vehicle is limited in its acceleration at low speed only by the amount of torque it produces at the rear wheel, and at high speeds by horsepower. The transition speed, the speed at which horsepower becomes the limiting factor instead of torque, depends on a lot of things, but on my SR it seems to be somewhere in the 60-80 mph range. Even at speeds near or somewhat above the transition, the instant power delivery and lack of a need to shift down three times makes our bikes good performers even at freeway speeds.
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You can believe Biff, he knows what he's writing.
I don't believe anybody who "knows what he's talking about" but doesn't cite any sources or even say WHY he believes what he believes. Just one more voice in the wilderness until that time.
What you feel as acceleration is simple said torque x rpm - resistances. The more horsepower the more acceleration, simple.
Uh, no. Torque is the rotational analog of force (twisting instead of pushing in a straight line), and no less of a scientist than Sir Isaac Newton tells us that force equals mass times acceleration. Horsepower does NOT cause acceleration, torque does; it's just that simple. Horsepower is the ability to supply energy at a high rate of speed, which is only necessary when losses are high, as at high speed. Numerically, horsepower is equal to torque (in ft-lbs) times rpm divided by 5250. In the real world, there are always losses (what you call "resistances"), which is why torque and horsepower are a bit lower when measured at the rear wheel than when measured at the engine....but in any vehicle, losses are pretty small. In a drivetrain as simple as ours is, losses are near to being negligible.
In the real world, a vehicle is limited in its acceleration at low speed only by the amount of torque it produces at the rear wheel, and at high speeds by horsepower. The transition speed, the speed at which horsepower becomes the limiting factor instead of torque, depends on a lot of things, but on my SR it seems to be somewhere in the 60-80 mph range. Even at speeds near or somewhat above the transition, the instant power delivery and lack of a need to shift down three times makes our bikes good performers even at freeway speeds.
Well said!
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Believe what you like but the same vehicle with more horsepower will accelerate faster. Even if the motor has only 10% of the torque, because at same wheel speed you will have more wheel torque if geared for same top speed.
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Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
Please stop proliferating this rumour, It is not true. ...
I'm not "proliferating" anything, and certainly not what you call a rumor. I think it's fairly clear if you read my comment that I have nothing but a suspicion and suggestions. I'd certainly like someone with credentials and evidence to get on and put it to rest, and I'm certain there are more than a few who read this who could.
The only dog I have in this fight is the fact that different types of motors have different stall torque characteristics, period. Does the Energica motor have lower stall torque than a similar (100kw or so) PMDC motor? Yes. Is that why I couldn't wheelie it? No clue. I have no idea if it was mapped or not, and I really don't care.
Believe what you like but the same vehicle with more horsepower will accelerate faster. Even if the motor has only 10% of the torque, because at same wheel speed you will have more wheel torque if geared for same top speed.
As far as horsepower goes, you need to have a really basic understanding. Horsepower = (Torque x RPMs) / 5252. End of discussion. http://danielmiessler.com/study/horsepower/ (http://danielmiessler.com/study/horsepower/) So explain to me how you can have a vehicle with 10% of the torque and more horsepower.
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Believe what you like but the same vehicle with more horsepower will accelerate faster. Even if the motor has only 10% of the torque, because at same wheel speed you will have more wheel torque if geared for same top speed.
As far as horsepower goes, you need to have a really basic understanding. Horsepower = (Torque x RPMs) / 5252. End of discussion. http://danielmiessler.com/study/horsepower/ (http://danielmiessler.com/study/horsepower/) So explain to me how you can have a vehicle with 10% of the torque and more horsepower.
Nothing simpler than this, if it delivers the 10% torque at the 15x rpm than the other motor.
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Nothing simpler than this, if it delivers the 10% torque at the 15x rpm than the other motor.
So, most AC motors run in, say, the 6000 RPM range. You know of a motor that runs at 90,000RPM? If so, I'd love to know about it. :D
Nevermind, I probably can't afford it. :P
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Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
Please stop proliferating this rumour, It is not true. Zero does not limit off the line torque. You can hold the rear brake, go full throttle and measure RMS current into the motor and you will see that it is the maximum that the controller will deliver.
Also feel free to install accurate accelerometers on the motorcycle (or accurate wheel speed sensors) to measure acceleration, you will see that it is constant from 0 to around 40mph (at which point wind starts to cause decreased acceleration, and as speed increases the constant power section of the power curve limits acceleration).
Thanks,
-ryan
How do they regulate the power then?
The fx is "limited" 0 to 30
My other which is much less limited sure seems like it has 2x the power from 0 to 30
you can read my lengthy comment here to find out my theory as to why people think the torque is limited at slow speed.
http://evmc2.wordpress.com/2014/07/07/motor-starting-torque-stall-torque-and-motor-types/ (http://evmc2.wordpress.com/2014/07/07/motor-starting-torque-stall-torque-and-motor-types/)
I have instrumented bikes and verified the torque delivery, it is very linear from low speed up past 60mph. And as you said you feel like your FX (I believe it has a size6 controller now) has 2x the power of the stock FX, that is right in-line with my theory that what scares people, or gets the front wheel off the ground easier feels much more powerful than it actually is. Once you get used to it, I bet your acceleration will feel more tame.
To answer your question "how do they limit power" . Power is the product of torque and speed (Watts = RPM * Torque * pi/30) where Torque is in Newton Meters. The motor controller (stock FX) delivers 420 phase amps maximum, since phase amps is directly proportional to torque (ignoring any iron saturation and other minor non-linear effects) that means the motor torque is limited by the motor controller. At 0RPM there is 0hp (because speed is 0) as speed increases power increases proportionally until the the motor controller can no-longer put 420A into the motor (BEMF from the motor approaches the Votlage of the battery).
-ryan
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Zero does not limit off the line torque.
Seriously then what is it! That S that I rode didn't feel like it had half of the 68 ft-lbs that is advertised. That's not criticism or skepticism. It would be nice if someone who really knows would explain it. My asses accelerometer is very accurate and it read nowhere near 60.
This brings up a good point, and I allude to it a bit my comment on Ted's page but not specifically. What your butt-dyno is telling you is acceleration, which is motor torque * gear ratio / tire size / vehicle mass. If you don't know the gear ratio, you have know way of feeling the motor torque, People often look a the motor torque and think wow that should really accelerate hard, but actually motor torque has nothing to do with acceleration, it is all about wheel torque. It is funny but even many magazine articles and TV Shows (Top Gear In particular) talk about how torque from a motor or engine is important, when in fact it has very little to do with actual performance. A Torquey motor would actually best describe a motor that has a nice wide flat torque area, so that you can actually remain in its "peak torque" range for a wide range of vehicle speed without having to change gears, or perhaps more commonly a motor that has high torque at low RPM, so you don't have to rev the engine that much from idle before you can release the clutch and get moving really well.
As the graph that tyskmoped posted, a gearbox on a small engine can produce more wheel torque than the single gear of the Zero does, and assuming both vehicles are about the same weight the small gas engine should accelerate harder. The big difference is that the gas engine torque drops off and you need to shift gears as speed increases, the Zero motor doesn't, so the Zero will accelerate faster than the gas bike when you are in that speed range. In fact I believe that the acceleration is more than you expect which makes it feel like it is actually accelerating faster than it was at lower RPM which is simply not the case. This leads to the feeling that I admit everybody gets, that the Zero's accelerate harder at 30-60mph than they do from 0-30mph, when in fact the acceleration is very linear from 0-60.
One thing that has been brought up in this thread is that why no motorcycle dyno plots from electric motorcycles start at 0 RPM. It has been my experience that dyno's control loops and torque estimation are tuned for 15mph and higher. Below that the eddy current braking and roller speed are changing too quickly for the system to accurately calculate the actual wheel force, probably because nobody really cares about power below 10mph on a gas bike since you are typically slipping the clutch at those speeds if you are trying to get the fastest acceleration anyways.
Another thing that this thread has brought up is weather torque vs hp is more important to acceleration. As I mentioned above neither of those things on their own gives you any information about acceleration, you need some information about wheel speed , and possibly gear ratio to with it (and the assumption vehicles have similar weight and wheel size). What matters for acceleration is wheel force. That is either motor torque * gear ratio / wheel size, or motor power / rpm *gear ratio / Wheel size. Having a motor torque curve vs speed for both vehicles, or a motor power vs speed for both vehicles makes an easy comparison, but unless you have such a curve, there really isn't any way to compare 2 vehicles.
-ryan
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Believe what you like but the same vehicle with more horsepower will accelerate faster. Even if the motor has only 10% of the torque, because at same wheel speed you will have more wheel torque if geared for same top speed.
Um, again, no. I'm not trying to argue with you, or make you feel bad, I'm just correcting you. You persist in denying what any Physics 101 class in any college could teach you has been known and accepted for literally 500 years now: Force = mass times acceleration, F = ma. Isaac Newton formulated the law and everyone from high school Physics teachers to every engineer around to NASA understands and agrees that it's true. It's not power that accelerates an object such as a vehicle, it's force, or its rotational analog, torque. High power only becomes necessary as energy is drained from the system at a high rate of speed (such as aerodynamic drag becoming very large at high vehicle speeds), and has to be replaced. That's why power is so important to racing vehicles, which need to attain the highest speeds possible, but torque is far more useful at lower (street-legal) speeds.
Hit up wikipedia or Google and learn some facts. Reality is a pretty nice place to live.
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This brings up a good point, and I allude to it a bit my comment on Ted's page but not specifically. What your butt-dyno is telling you is acceleration, which is motor torque * gear ratio / tire size / vehicle mass. If you don't know the gear ratio, you have know way of feeling the motor torque, People often look a the motor torque and think wow that should really accelerate hard, but actually motor torque has nothing to do with acceleration, it is all about wheel torque. It is funny but even many magazine articles and TV Shows (Top Gear In particular) talk about how torque from a motor or engine is important, when in fact it has very little to do with actual performance. A Torquey motor would actually best describe a motor that has a nice wide flat torque area, so that you can actually remain in its "peak torque" range for a wide range of vehicle speed without having to change gears, or perhaps more commonly a motor that has high torque at low RPM, so you don't have to rev the engine that much from idle before you can release the clutch and get moving really well.
First I should say that I've been a mechanic, racer and motorcyclist for between 10-20 years respectively so I know how to calculate torque, HP and that rear wheel numbers are quite different than engine/motor numbers.
One thing that we've discussed was if the "claimed numbers" were motor or rear wheel. I feel that Richards post put that to rest since the SRs tested ( chassis dynoed/rear wheel ) numbers were not only consistent with but over the claimed numbers. I feel comfortable saying that if that is the case with the SR then its likely the same with the other Zeros. So in that case the Zero S that I rode would be putting down around 60ft-lbs with a 400lb machine. That is quite close if not on the money with a modern 600cc sportbike. Now since the torque is measured at the rear wheel then gearing is no longer a factor since all parameters are set ie.. each bike has its final ratio and any gear position locked in and they are both on par ( close enough ). A similar foce pushing a similar weight should have a similar outcome, no? I know that the gas engine is spinning at 6-8k rpm but that's its power band where the electrics is said to be 0-6000k rpm.
I've read you comment on Teds page twice now and it really doesn't answer any question for me. The things that im discussing aren't quite as subjective as how it feels to me. Its does the wheel lift or tire break loose. Cortezdtvs bike does without doubt but sadly I never rode it :'( and we know that the amps is related to the torque but even the Fx that I rode lifted at 20mph.
Wow its time that I stop! Reading and writing these long drawn out posts that seem to go nowhere is exhausting :-X
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I refer to it as pushing down rather than "lifting" like you do on a fx
Chd where are you from?
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I've read you comment on Teds page twice now and it really doesn't answer any question for me. The things that im discussing aren't quite as subjective as how it feels to me. Its does the wheel lift or tire break loose.
Exactly how I feel about the comment as well. Very true, but missing the point. There's a lot of keyboard smarts here, and not a whole bunch of real-world experience. There's also some basic understanding that's AWOL. Forgive me for being frank. Just callin' it as I see it.
And ditto on the exhaustion. Gonna get off the forum again and go back to the shop now... ;D ..hopefully it's a little warmer than 20º by now. :o
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Believe what you like but the same vehicle with more horsepower will accelerate faster. Even if the motor has only 10% of the torque, because at same wheel speed you will have more wheel torque if geared for same top speed.
Um, again, no. I'm not trying to argue with you, or make you feel bad, I'm just correcting you. You persist in denying what any Physics 101 class in any college could teach you has been known and accepted for literally 500 years now: Force = mass times acceleration, F = ma. Isaac Newton formulated the law and everyone from high school Physics teachers to every engineer around to NASA understands and agrees that it's true. It's not power that accelerates an object such as a vehicle, it's force, or its rotational analog, torque. High power only becomes necessary as energy is drained from the system at a high rate of speed (such as aerodynamic drag becoming very large at high vehicle speeds), and has to be replaced. That's why power is so important to racing vehicles, which need to attain the highest speeds possible, but torque is far more useful at lower (street-legal) speeds.
Hit up wikipedia or Google and learn some facts. Reality is a pretty nice place to live.
Maybe I did write something wrong in my first post as English is not my home language. I know the physics, it is very kind of you to teach me, thank you. For me it seems as you want to read something I did not try to say.
I try again. Motor torque alone isn't the only/main indicator for acceleration. It depends on the curve how it is delivered and at which speeds. To make it more clear what I mean, here an example. Which bike accelerates faster? Zero Fx 2.8 with 94nm torque and 27hp or an 250 KTM with 35nm/40hp?
I did share two diagrams with you, both are from dynos I did myself. The first (red) shows the torque curve of a Fx 5.7. In my world it shows that the torque is not limited, it's constantly at maximum till other things than the setup let it decrease.
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I refer to it as pushing down rather than "lifting" like you do on a fx
Chd where are you from?
I don't quite understand what your saying there. When I say lifting im referring to the front wheel not with my arms and yanking. The FX was throttle alone but I could see how you'd be pushing down or leaning over the front of your bike and still popping a wheelie :).
I live in a place called New Bedford Ma. ( from Moby Dick ) between Rhode Island and Cape Cod.
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To me if you try to wheelie in an aggressive riding position (leaning. Forward elbows up) from 0 mph. The fx won't really pick it up until 20 30 I mean yes if you give a little tug up or lean back a little it will come up, but it doesn't have enough to pull you up if you were leaning as far forward as you can
Mine is like push down as hard as you can from 0mph and half to 1/4 throttle. Climb on the front of the bike feet hugged around the front controller area. And ride that wheelie to 70, first time I tried drag it I wheeleid the whole street far from what the fx can do all in a power wheelie
First few times I tried to "drag" some big 650 enduros I just weelied toying with them then I relized I need 600 street bikes and up to stoplight to stoplight; depending on the rider than can be pretty even, put a professional on one and I'm sure I'd probably get left racing is all in the rider
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Mine is like push down as hard as you can from 0mph and half to 1/4 throttle. Climb on the front of the bike feet hugged around the front controller area. And ride that wheelie to 70, first time I tried drag it I wheeleid the whole street far from what the fx can do all in a power
How did you realize this improvement?
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Mine is like push down as hard as you can from 0mph and half to 1/4 throttle. Climb on the front of the bike feet hugged around the front controller area. And ride that wheelie to 70, first time I tried drag it I wheeleid the whole street far from what the fx can do all in a power
How did you realize this improvement?
Not sure I understand?
What do you mean how do I know it's faster?
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How did you make it faster?
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Spent way to much money and time 8)
I upgraded the motor and controller for basically what's in the SR with a "limited tune" because unlike the sr I only have 2 batts compared to its "4."
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Stall torque and it's effect on 0 RPM performance is not a theory, just to be clear. Given that, you're talking about two different things - acceleration from 0 RPM, and acceleration from well onto the torque/power band to a higher RPM. Seems like it'd be hard to measure, but if it's the case, it would certainly suggest throttle mapping, which it sounds like we've confirmed is what Zero is doing.
My suspicion is that they're concerned with riders who are unaccustomed to riding without a clutch. Most experienced riders will use the clutch to feather power off the line, even during hard acceleration on the power band, and in some cases use it for low-speed control of power. You don't have that kind of option with an electric motor.
Please stop proliferating this rumour, It is not true. ...
I'm not "proliferating" anything, and certainly not what you call a rumor. I think it's fairly clear if you read my comment that I have nothing but a suspicion and suggestions. I'd certainly like someone with credentials and evidence to get on and put it to rest, and I'm certain there are more than a few who read this who could.
The only dog I have in this fight is the fact that different types of motors have different stall torque characteristics, period. Does the Energica motor have lower stall torque than a similar (100kw or so) PMDC motor? Yes. Is that why I couldn't wheelie it? No clue. I have no idea if it was mapped or not, and I really don't care.
Believe what you like but the same vehicle with more horsepower will accelerate faster. Even if the motor has only 10% of the torque, because at same wheel speed you will have more wheel torque if geared for same top speed.
As far as horsepower goes, you need to have a really basic understanding. Horsepower = (Torque x RPMs) / 5252. End of discussion. http://danielmiessler.com/study/horsepower/ (http://danielmiessler.com/study/horsepower/) So explain to me how you can have a vehicle with 10% of the torque and more horsepower.
Ted- You are mistaken. Biff is trying to set you straight. Biff knows this better than any other human on earth I have awareness of, you would be wise to listen rather than continue spreading falsehood.
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Please be specific. What precisely am I mistaken about?
I ask because it seems we have about 3 discussions going on here. Correction - 4. One about the characteristics of motors, one about riders perceptions of performance, and one about Zero's tuning of their controllers, and finally about what makes acceleration.
As far as I understand it, different motor designs have different stall torque characteristics, by their design. Is that correct? (...and that's the only point I'm trying to make, as I've said. Since I've talked about it with motor designers and thought they confirmed this, I'd love to know what I got wrong. Sincerely.)
I think I have a firm grip on perceived performance vs. actual numbers, since I've been building motors and bikes for a few decades now.
I don't particularly care whether Zero is mapping their response or not. As I've said a few times now, my comments were simply guesses and discussion. If someone reads those comments as perpetuating rumors, that's an issue with their reading comprehension.
On what makes a machine accelerate, I really don't think I'm mistaken about basic physics, am I?
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So I've been scratching my head about this, and the comments above, and went back and re-read Biff's comments as well as his comments on my blog post. Here's the point that was interesting:
3) Many DC motor controllers have the current sensor on the input to the controller, on the battery side. When the motor is stalled or spinning slowly the battery current will be very low even though the motor current (torque) is really high, once the motor is spinning more quickly and the power increases, the battery side current also increases bringing the current into the range that the sensor is more accurate and the controller will then have a better time controlling the motor current based on the battery current. Also Many DC controllers are speed control, so when you change the throttle position it tries to give everything it has to get you to the new commanded speed, so they give you a big punch initially until you get closer to the desired speed.
So that's what I missed, but that begs the question, are you saying that this behavior of a DC controller is completely responsible for the different response of the two types of motors, or are there measurable differences (as I've been told there are)?
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Can you find the TTXGP crash and show specifically where it was a bearing failure of the motor? I am sure there must have been a huge write up about this somewhere. That stated I am not racing my bike but it does have ceramic bearings in the motor.
I didn't find the video but it is one of the missing you tube videos on one of the articles. I knew it wasn't a dream! ;D
http://plugbike.com/2009/10/26/2010-ttxgp-rules-published/ (http://plugbike.com/2009/10/26/2010-ttxgp-rules-published/)
http://electricmotorcycleforum.com/boards/index.php?topic=420.0 (http://electricmotorcycleforum.com/boards/index.php?topic=420.0)
http://green.autoblog.com/2009/06/10/ttxgp-complete-wrap-up-of-first-day-of-qualifying-w-video/ (http://green.autoblog.com/2009/06/10/ttxgp-complete-wrap-up-of-first-day-of-qualifying-w-video/)
http://www.motorcyclenews.com/sport/tt-road-races/2009/june/jun1009-ttxgp-story-behind-first-crash/ (http://www.motorcyclenews.com/sport/tt-road-races/2009/june/jun1009-ttxgp-story-behind-first-crash/)
Ironically the eRocket bike had a six speed gear box but no clutch so an emergency disconnect was mandated by the TTXGP.