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[teddillard]

"Impressive" as I expected ZEV to use a larger than Zero battery to deliver Zero level ranges. ...

If they're using LiFePO4, then they would be using a larger battery, not to pick nits.  NCM is both more power- and energy-dense. 

[dhzehrbach]

Lots of questions.  In turn

ERASMO -as you suggested- I note, I am the designer of the bike, the head engineer and the President of ZEV.

You asked --The next model will be a 10 kwh battery pack like the ZEV LRC scooter that now runs 140 miles at 55 mph.  84 volt nominal, 15 kw continuous.  We will see if there is any request for an in the tank storage space range extender, ala ZERO power tank.  Easily done.

There is a motor laying in the shop for 20 kw higher rpm running.  We know from testing in coast down and in towed drag measurements, that the bike can run 100 mph on 20 kw or 118 on 24 kw.  Maybe in 2017 and then make the parts available as retrofit for anyone.  I just cannot get to this for awhile.  This whole motorcycle project has taken several years.  Just not enough hours in the day. 

Beyond the 20 kw, there is a large faired cruiser type bike carrying 25 kwh of battery that runs over 300 miles on a charge.  About $20,000-$22.  Before committing on that bike we will see where this current model design leads us.

Mr. Wilson ---as you say, the ZERO charger is 1.3 kw, the standard ZEV is over 2.  We could use the larger chargers, but the feedback from customers is they hate the price of the large chargers.  Its cheaper to put extra battery in the bike.  $3,000 of charger buys double the battery pack.

 If I made the 15 kw, 84 volt nominal bike with the extra in tank battery for range, then added the fast charger, it would be cheaper to build the 300 mile range 25 kwh bike. 

Survey of car owner show that over 90% never buy the extra charger.  They just use the small one in the car and let it set 8-9 hrs.  Bike use seems to follow this pattern.  Its rare that anyone asks me for a bigger charger.  They do ask for a bike design with more total range.   But we are already seeing at the 140 miles of the LRC motor scooter that there is a new trend.  Not charging.  We are seeing that people buy bikes with the intent that they can drive 30 miles a day commute, and only charge every 4th or 5th day.  Not good for the battery, and not what I intended, but it’s what they do.

We do have adapters available to go to 220 plugs and the charger has a 110/220 toggle switch on it standard for a faster charge than what we list.

The controller is inboard from where a pannier would hang on the rear.  No interference.
Pack voltage on this first model bike is only 72 volts nominal.   

CNTRBURN---Hub motors need not turn rpm, as even on the 84 mph LRC scooter with a 13 inch wheel, its never over 1400 rpm.  On the taller 18 inch wheel, its really loafing.  So the span of rpm between 0 and max is so little the torque is very linear. 
We are a bit odd in that we heat the motors in a hot box to 300 degrees F, and then put them on the dyno.  They run there at max power as we watch the temperatures come down while running full power.  When the temps stabilize, we hold another 3 minutes of full power.  Then we check the torque and rpm, etc.  So the torque is sustainable. 

The hub motor has some advantage in that it is not buried in the chassis like the ZERO motor so it gets good cooling air.  Since it is turning, it is its own cooling fan.  The entire wheel becomes  heat sink/cooling fin. 


TEDDILLARD – You are not even remotely in the realm of weight or logic.  No hub motor on any of the bikes we make weigh remotely what you guessed.  You must be thinking about big truck motors.   To compare you would have to put a chain or belt type drive wheel on the scale, toss on the chain or belt, add the chain or belt sprocket.  The guts out of the hub motor, is 9.4 kg leaving an outer wheel and rim of similar weight to say a ZERO.  You will need to deduct back out of the 9.4 the chain or belt and sprocket drive to create an equal comparison.   My guess would be about 5-9 lbs difference.

You have to consider also -Racers often load the axles of the bikes to deliberately make them heavy.  When I drag raced my ZX, I used slabs of lead on the front fork legs at the axle to make sure the front stayed down and when coupled with the limit straps on the front, did not hook and eat me.  Some guys fill the hollow front axle with lead.  Similarly, and to address your claim, road racers run bikes with large hollow axles, so in traction challenging tracks, the “tune” is to fill that monster big hole in the axles with lead and sometimes to fasten slabs of lead on the rear swingarm.  Usually the lead is worth about 3-5 lbs of load at the axle depending on the bike.  When lead loaded, there is probably no weight difference vs the hub motor.


People are quick to talk about unsprung weight, but do not stop to think:
a)   What does the chain, sprocket drive weigh?
b)   What is the weight of the center of the chain drive wheel that the hub motor does not have?
c)   For comparison, what is the weight of the ring and pinion and rear shaft drive parts in a BMW motorcycle?

We are building a 20 kw version of the hub motor with a spoked wheel and rim for a SuperMotard Racebike prototype.  Pounding though the dirt and then onto the asphalt and back again will certainly show any issues.

[teddillard]

How about you just tell us what the complete motor/tire/wheel assembly weight is?  Then it's a simple comparison, once you throw in half a belt's weight to a Zero assembly for good measure.  I'm guessing your motor accounts for about a 30lb difference, based on the power claimed.

I've worked with a 10kW/20kW (peak) hub motor strung on a Ninja wheel.  That assembly was easily in the range of 60-80lbs. "Not even remotely in the realm of weight of logic" indeed.   

People who "are quick to talk about unsprung weight" being insignificant are ignoring one thing - the entire body of suspension engineering work in the automotive and motorcycle industry.  As I've said many times before, if you argue that it's not important or significant to your riding style or demands, fair enough.  You prefer the feel?  Fine.  The tradeoff of available space makes it worth the hit on the handling?  Be my guest. 

If you're arguing that it doesn't have a negative impact on handling, or it enhances the handling in some magical way, you're simply misunderstanding, or misrepresenting physics.   (Loading lead on racing suspension?  Please. Be serious.) For those who want to learn more about unsprung weight, here's a good place to start: http://www.formula1-dictionary.net/unsprung_weight.html

[Erasmo]

Do you have something against hub engines? More unsprung weight shouldn't be a problem if the engineering behind it is solid. Both my Honda and BMW are shaft driven and those final drives aren't lightweight. But I guess now I know why insideeevs doesn't mention this new bike.

Lots of questions.  In turn

ERASMO -as you suggested- I note, I am the designer of the bike, the head engineer and the President of ZEV.

You asked --The next model will be a 10 kwh battery pack like the ZEV LRC scooter that now runs 140 miles at 55 mph.  84 volt nominal, 15 kw continuous.  We will see if there is any request for an in the tank storage space range extender, ala ZERO power tank.  Easily done.

There is a motor laying in the shop for 20 kw higher rpm running.  We know from testing in coast down and in towed drag measurements, that the bike can run 100 mph on 20 kw or 118 on 24 kw.  Maybe in 2017 and then make the parts available as retrofit for anyone.  I just cannot get to this for awhile.  This whole motorcycle project has taken several years.  Just not enough hours in the day. 

Beyond the 20 kw, there is a large faired cruiser type bike carrying 25 kwh of battery that runs over 300 miles on a charge.  About $20,000-$22.  Before committing on that bike we will see where this current model design leads us.

Thanks, that intersting. It's good to see affordable faired bikes finally entering the market.

[teddillard]

Since when is factual information "having something against" something? (...and it's "motor", not "engine"   )  Believe what you want, but if you want facts, as I said, follow the link.

I don't, and have done a considerable amount of research on them, if you'll read my blog.  I think they're great on skateboards, scooters, trucks, and, like I said, if you're willing to take the hits that they impose, great on motorcycles.  I've ridden them, worked on them, and have several friends who built hub-motor based bikes.  I've had long conversations with both Mark at Enertrac about his 10kW motors and the dual-hub 20kW motors, as well as Jon from Catavolt who raced them very successfully in Australia, but ultimately found them to be not competitive at today's levels of performance. 

Nowhere do I say I have anything against them.  That's actually why I object to the term "phobia".  It suggests an irrational fear.  If you want to refer to a bunch of research, a solid understanding of motorcycle handling and fact-checking irrational, I don't know what to say.

Here's the summary: https://evmc2.wordpress.com/2014/07/08/understanding-unsprung-weight-hub-motors/

What I do have an issue with is when people misunderstand or misrepresent the physics of unsprung weight to try to spin hub motors into something they're not. They are not, in any modern sense, a viable option for any performance-handling focused bike, and this bike doesn't compare in performance to a Zero SR past 2013.

They have significant drawbacks, too, which I don't really care to go into.  I've done it all on the blog, as I worked out solutions for myself. 

As far as your fairly off-topic snipe InsideEVs doesn't have a story about this bike because I'm the guy who generally writes about bikes and scooters, and over the last 6 or so years I've had correspondence with ZEV, it's pretty hard to get to the truth of the specs and claims.  I was considering writing up this bike, in fact, but after visiting the site, there are so many stretched facts, omitted details and straight out untrue claims I don't have time to fact-check even just the ones on the bike and their top-end scooter.  I'm not going to validate a product by writing a story on it without knowing as much as I can about it.  Beyond that, we generally write about stuff that interests us on the site, because we do it out of passion, and frankly, this bike doesn't particularly interest me.  I'll forward your interest to the editor and maybe someone else will be interested enough to write it up.

I've pointedly tried to avoid commenting on ZEV as a company, to try to keep the discussion based on the features of the bike, and the facts about hub motors. 

You brought it up, sorry.   

I will admit, however, I don't particularly like scooters, electric or otherwise.  ...except silly ones.   

[Richard230]

I tend to agree with Ted about the impact of unsprung wheel weight on motorcycle handling.  I think it probably isn't that much of an issue on smooth roads, but can be a real problem when hitting pot-holed, bumpy and poorly maintained roads such as we have all over California. It is really tough for the suspension to deal with the inertia of a bouncing heavy wheel such as one containing a hub motor.  Still, I can appreciate the simplicity of the design and the fact that it allows more room for additional batteries in the bike's chassis.

However, another concern for me (and one that I don't believe has been brought up yet) is how do you cool the motor? All of the hub motors that I have seen (such as the one used in the Vectrix) are completely sealed to protect them from the elements and can get very hot very quickly when asked to push the bike uphill or to high speeds for more than a few minutes.  Unless there is some way to remotely cool the motor, such as via water cooling, the hub motor is going to quickly overheat and cut its power output - likely at a time when the rider might just need that power to prevent becoming a car's hood ornament. 

[teddillard]

They claim the motor is oil cooled.  I was unable to determine which motors are oil cooled, how they're oil cooled (whether just by having oil passages in the motor, passively, which is what it sounded like to me when he described it to me a few years ago, or if there's a pump and a radiator, as most motors are that are "oil cooled") what the cooling options are (most motor manufacturers offer a few options on liquid cooling and air cooling) and how that figures into the load ratings.  Maybe Mr. ZEV can answer.   

[dhzehrbach]

Let me see if I can address these in turn.

Mr. Dillard
Since you stated "be serious" in the reference to lead loading of axles.    Please search articles on MotoGP.  You can start with Cycle World's November 2015 issue, "Feeling the Edge", page 67.  "The usual fixes(like lead-filled axles---worked for Honda but not for Yamaha."    I would admit that it is probably hard for you to find information such at that as most race bike tuners and engineers like myself do not publish their trade.

See also the forum that a quick search turns up on page 1, http://www.psychobike.com/forums/archive/index.php/t-37028.html

 
RICHARD 230
The Vectrix motor is not a hub motor.  Its a small high rpm motor mounted in the side of the swingarm, not in the wheel.  The motor shaft sticks through the swingarm and into a planetary gearbox.  You are correct, that motor, sealed up and under a cover with air flow does get quite hot.

At the 13-20 kw level, there is no need for cooling by any pumped flow means.  The oil cooling is passive.  On a 15 kw motor --After running sustained 80 mph on local mountain roads for 13 miles, then up an 8% grade, 5 miles long, at full throttle, with two 80 lb sandbags and a 168 lb rider, on a 92 F degree day, the motor reached 132 degrees F on the hottest point inside the motor.  It showed 123 F on the motor side plates.   The advantage is that the motor is turning in the breeze, and not relying on passing air entirely.  It gets both.  We are also using the entire wheel and spokes and the rim as a heat shedding surface.  That is a lot of surface area spinning at over 1200 rpm and finned.  The surface area without the fins on the ZERO motor is about 30% less than the surface of the ZEV motor without counting the total area including the wheel and rim being used to dump the heat.  That spinning and resulting high velocity air scrubs off the heat over the large surface area. 

That is a lot more effective than a motor such as the ZERO, which while heavily finned, sets passively buried in the chassis with no cooling air ducts to it, and the fins turned sideways to the forward motion.  Further, fins on a motor are not very effective if the heat does not get to the finned area.  The ZEV motor is finned on the inside also for that reason.

GENERAL
Within the confines of street bike spirited riding, even at high lean angles, but without dragging the slider pucks on the knees of my leathers, the hub motor weight is of no consequence.  People worry to much about the weight.  If it was all about ounces, then no bike would add a second iron disk and caliper on the front for more braking.  They would ponder the weight shift of the change to inverted front forks.  They would run smaller tires to cut tire weight. 

The motor in the rear wheel weighs 9.4 kg.  You need to deduct the weight of the chain drive sprocket or belt sprocket and the chain/belt on a non hub to have a comparison.  Both types have an axle.  That weight would be in common.  We can assume that the weight of the wheels themselves without the motor would be similar.

[teddillard]

Why don't you have the weight of the assembly?  Seems like that'd be data you'd have at your fingertips, considering the suspension had to be designed around it.  (As far as your link, drag racing doesn't, last I checked, involve much in the way of bumps and twisties. When it does, things are going badly.   ) I'll stick to the advice of my MotoGP tuner friends, thanks.

This is what I mean.  WAY too much effort to get simple facts.

Back to what unsprung weight is all about if anyone still cares, it's important, too, to understand how incremental weight turns into significant weight with the addition of a few Gs.  If you have one pound of unsprung weight, hit a bump, and get 2Gs, you now are suspending and damping 2lbs.  Now, imagine the ZEV is a miracle motor and weighs 20lbs (the legendary ETEK is about 25lbs and is 7.5kW, if memory serves), you hit a bump, get 2G, now you're looking at 40lbs of inertia slapping your bike around.  This is why stuff like inverted forks (which are stronger, as well as having less unsprung weight, to answer that question), trailing calipers, stuff like that is so important. Ounces DO matter. A pound here and a pound there, pretty soon you have a nice little tank-slapper going.

OK, I'm done.  I've done this before, not going down this road again with the guy.  Ciao.

[dhzehrbach]

Ted Dillard

The 9.4 kg is the weight of the motor assembly as you asked.  The wheel it fits in is 7.8 kg.

I see you ignored the MotorGP article on lead filling axles and choose to seize upon a claim that drag racing does not count in your book --regardless of speeds or track conditions.  Ever been down the strip at 150+ Ted?  Think the straight on a drag strip is different than the straight on the highway or on a road course? Think there no bumps and dips on drag strips?   Ever been on the Ohio Mile, or other such runs?

Actually, you argue against yourself with the no twisties comment.  The more a bike heels over, the less suspension in the bike.  When upright the suspension works fully.  At the extreme, when the bike is really heeled over, the force vector is into the side of the wheel and little if any suspension movement occurs.  So on really bumpy tracks, its common to see race engineers run higher sidewalls in the tires so that becomes the suspension.  The chassis also has to be made to flex.  There was a time when chassis flex was the huge enemy, and chassis got more stiff --right to the point when bikes started handling badly, worse than ever, and flex was re engineered back into the chassis a few years  back. 

 Your argument is incorrect in that 1 lb weight does not jump to a 2 lb weight with 2 g.  You assume it accelerates with the weight of a feather, but weighs like an anvil when in motion.  So back to the lead weights in the axle - higher weights resist g force by their inertia and do not just jump like you imagine.  Further, any such action is further dampened by the tire sidewalls.  Still further, such action is complicated by the rim width to tire width ratio mitigated by the sidewall height. 

A common mistake is for people to assume that the reason engineers work on the weight of wheel assemblies is all about unsprung weight.  The main factors are to reduce rotational enertia so the bike will accelerate and stop quicker, and total vehicle weight, as in how it effects power to weight.

While trying to make a point on the unsprung weight issue, do you have a clue what rear wheels on motorcycles really weigh?  What does the rear wheel full assembly of a Honda SV1300 weigh, Harley anything, Hayabusa etc.   We are not designing a MotoGP bike here Ted.  This is about street bikes where bikes do not go into tank slappers because their rear wheel weighs more than that on race bike. 

For the ultimate in what is very high unsprung weight, do you know what the entire motor and rear wheel assembly in a Suzuki 650 Burgman weighs?  Now its not just the scooter drive train in a small diameter wheel, the twin cylinder engine is on that swingarm also.  Yet big scooters like the Burgman or the Honda SilverWing have no issues running well over 110 mph and faster, faster than the bulk of the electric motorcycles that have been made--and doing it on 13 and 14 inch tires.

I am in this business to make vehicles, not just motorcycles, and not just to bench race.  We make good solid value motorcycles/scooters/trikes that have sold worldwide for now coming on 10 years.    There are clearly a lot of owners who do not get on the forums and complain that the unsprung weight is so terrible as Ted Dillard claimed. Never one. The absolute absence of such comment should be proof enough.  After 10 years, you seem to claim that we must be blind to the issue and that all of those ZEV owners must be suffering catastrophic handling issues.  Sorry Ted, its just not the case. 

[teddillard]

Last try.  I did not ask for the weight of the motor assembly.  I clearly asked for the wheel, motor and tire assembly, thus eliminating any doubt as to the additional parts and pieces you feel will add up to what?  Almost the weight of the hub motor?  Preposterous. 

...and I did not ignore your MotoGP comment.  Did you not read my response?  This is ridiculous, good luck selling your "motorcycle".



(update:  I just had a conversation with a friend who's got to remain unnamed, but suffice to say he's one of the foremost authorities on motorcycles in general and MotoGP in specific.  It's absolute "bunk" in his words, that tuners will add lead for unsprung weight for handling.  They will, occasionally, add weight to meet minimum requirements, but that will be near the CG of the bike, which is not, by the way, as low as possible - in fact, good handling demands a higher CG than what might be intuitive.  Any handling work is always - always - about lowering the unsprung weight. 

Though I don't have weight on a Zero SR rear wheel assy, best guess is not more than 20lbs complete.  A good forged wheel the same size is 10lbs, you have your brake rotor, your cush drive and your axle etc, plus the pulley.  I figure that all weighs no more than 5lbs, but to be conservative I'll give it 10, until someone weighs a wheel for me.  That doesn't include the tire.  So your rear hub motor with wheel is a claimed weight of just short of 40lbs, 37 something, almost 20lbs heavier than the Zero.  ...though, frankly, I find it hard to believe that motor can take that kind of continuous power rating - but that's me being particularly skeptical.

Was that so hard?    )

[dhzehrbach]

As I said Ted, the motor is 9.4 kg, the wheel is 7.8.  17.2 kg total including the axle and nuts and hardware.

Tires weigh all sorts of different weights so lets stick to the hard parts.

The race ready ZX10R Galespeed front wheel is 10.45 lbs. and rear 18 lbs even for forged aluminum for the bike.  Most bikes are not as light as the ZX10.  These are naked wheel weights, no disks, etc., no sprockets., fasteners.

Now add the axle and nuts for the ZX wheel and the ZEV wheel in full, motor and wheel is 8.62 kg heavier than the ZX10R

Thanks for the best wishes on the sales.  The bike was first launched outside of the USA.  It is doing quite well, better than expected or planned.

[Burton]

dhzehrbach do you have plans to release a bigger scooter?

And by bigger I mean bigger wheels? I was talking with vetter about your scooter a year ago or so and he mentioned the tires were too small for stability with a streamliner (he speaking from experience with his little helix vs his previous bikes which had 16" tires)

He said he would have considered it had it had 16" tires on it because most of the work would be done to get the rider low.

[dhzehrbach]

Hi Burton,

The plans now are only with the 13 inch wheels and tires.  The CG is real low now, and no stability issues.  Probably the main difference between Craigs Helx and the LRC is about 12-15 inches more wheelbase.  That is a huge stabilizing factor that overwhelms tire diameter influence.  With the 15 kw LRC I can run 83-84 mph.  With a 20 kw bike that I am playing with I run 93-94 on the GPS.  The only straight I can get that is flat here in the mountains is a long bridge over a gorge where side winds are always present.  No problem though. 

The LRC is a bit of a streamliner as it stands.  That is why it gets the 140 miles on a 10 kw battery while the ZERO cannot do that at 55 mph on a 16 kw battery.  We have looked at adding some panels to go run in Craigs Ohio run of 140 miles total and putting in a 80 mile booster pack under the seat.  The total height of the LRC is lower than the new motorcycle which effects the drag also.

I invite you to come drive the LRC and see for yourself. 

[Burton]

You could easily make the scooter more streamline and give it a tail etc to compete ... you could even smooth out the front with some simple foam if you wanted to go the extra mile

I should be able to compete in the next Ohio challenge as by then my vetter fairing will be on the bike. I plan to run with the gas bikes when I do.

What is the range at 70mph+ (most vetter challenges are 70-80mph highway) and have you done any streamlining test beyond the final design ?