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[Eco Mouse]

Hello,

This seems like the right place to ask about EV motorcycles and scooters. I've tried at other EV sites, and get ignored, or berated for not searching or being in over my head. But my main interest is motorcycles, dual sport in particular. I've got this crazy idea about building a legit EV Dual Sport with insane range.

Anyway, I'm a designer and inventor and I have a design studio and fabrication shop. So, I can conceivably handle any build, but would probably get stuck when it comes to electronics. But I plan to take baby steps into the world of EV, so I can actually enjoy the hobby and save the planet at the same time.

[Erasmo]

Welcome to the forums, I've you're looking for enthusiasts and tinkerers you've come to the right place.

When you say insane range, how many km are we talking about?

[BrianTRice@gmail.com]

I'm also interested, making a Zero DS aerodynamic and faster charging. But I'm more inclined to assemble/customize than build from scratch. I don't expect to raise battery capacity, say.

Where are you located?

[MrDude_1]

There tend to be two types of EV builders. The first type knows all the electronics but nothing about building an actual vehicle. They tend to have very clunky vehicles that work, but are ugly. The second type knows how to build a vehicle, but lacks the knowledge of how to get the electronics to work. The second type often uses off the shelf stuff that ends up being less than innovative, ill  fitting, or not up to expected performance. The only way to make an amazing machine is to be a little of both. You have to understand electronic half just as much as the physical bike part. Then your expectations can be realistic.

[ctrlburn]

I, for one, "gave up" on building my own and bought a Zero when I realized how insufficient my myskillset was. Your EV forum flak may be from those who have also made that realization subconsciously or consciously guiding to back to the reality they have found and not being overly gentle about it.

That said it is 'easy' for and engineer to design a sleek motorcycle and label a small area "30kWh battery" and expect insane range and nimbleness from the finished product.

Not disparaging - I've seen seriously well rounded engineers and fabricators just miss some serious aspect of realism in their design spanning disciplines. 

Loiter the forum, look at how many watts per mile we consume (I average 130), check out the density of batteries and don't be surprised when something becomes insurmountable. As the professionals in the field are at the edge of possible right now.

And share... not qualifications and dreams but results and details of real hurdles. We celebrate some of the coolest innovations once completed (cowlings, colors, lights, storage, chargers, fenders, brakes, etc) but are naturally critics of what hasn't been done yet.

[benswing]

Good luck with your project! As a point of reference you get about 7 miles of range per kilowatt hour so if you want "insane range" you will end up with a heavy bike. 

Look up the Brutus electric motorcycle, it had a range of 200 miles I think.


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[MostlyBonkers]

Welcome and congratulations on finding this place. You'll feel at home in no time. I'm more of a thinker than a doer, but I did buy a Zero recently.

Please don't hesitate to post and I may be able to point you in the right direction at least. It'll be interesting to hear about your plans and follow your projects. [emoji4]

[Eco Mouse]

Well, I've decided to get my hands dirty on a Grom clone. For the price, I can easily feel free to tear it apart and tinker. Figure out what works what doesn't.

Just FYI, I'm building a trellis style frame for an e-Dual Sport as my long term project.

Anyway, back to the eGrom... stock it comes with a 2000w hub motor, 72v. It currently has 20ah SLA batteries. I want to upgrade to LiFePO4 soft pouches, to fit unique shape. I'm really hoping for 100ah. I can get BMS and Controller all from same battery manufacturer made to my specs.

Anyway, my question pertains to what size motor and voltage should I be shooting for, if I want Maximum Range and efficiency.

With my current wheel size, my choices are:
3000w and 4000w
(I'd be willing to go larger if you guys feel 6000w or 8000w hub motor is something I'd need)

Also, I have a choice of voltages. Currently a 72v system. But I see options for 84v and 96v in these wheel sizes.

Oh, and bike currently weighs in around 450 lbs with me on it at the scales. And I have a full fab shop, so I can cut, grind, weld and composite any part for my bike.

[Erasmo]

Ah I was already wondering how on earth a Grom would be suitable for Dual Sport.

Do you have a spec list or website where you got the Egrom from for us to look at? Also, at what speed are you planning to travel?

[Eco Mouse]

The grom is for now, and for fun. Just learning the quirks of EV at this point. The dual sport project would be my magnum opus. Right now, I've got slated a 3 cylinder diesel for that, unless I can really get into battery power.

Anyway, the specs I gave above are really all that is available until the bike arrives. 2000w hub motor, at 72 v, and the batteries are 20ah sla.

But I'm not interested in what it comes with, I'm interested in all the optional EV upgrades that are available on the aftermarket, and import EV suppliers.

The stock wheel is 12 inches, but I'll probably elect to go with a 14 inch. That also bumps me into the 8000w hub motor territory. If that's important. But I like options.

I've had a lifepo4 pouch cell made for me before to a specific size by some battery manufacture called ping or something like that. I'd have to pull up old emails. Anyway, they came highly recommended, and I was impressed with your work and ability to work within my constraints. I've since passed of those batteries to my client, for their project. My only involvement was to procure them, I didn't engineer that part of the project.

Which brings me here... Questions about 72, 84 and 96 volts,  and wattage of hub motors.

As for top speed, I don't care. Quite frankly, going over 80 on 12 or 13 inch wheels isn't something I'm going to be doing. I figure this eGrom project can just be my daily commuter. I've got a Triumph Tiger if I want to go further and faster.

But my main concern is distance on a charge. Because, I've got nowhere to charge in my condo. So I would only be able to charge at the shop. Plus all the errands and running I do throughout the day. I'd prefer 300 miles, because that's what I can get on my tiger, and it's predictable when I'll need to fill up.

I feel that's a main hurdle with the general public's perception about EV in general. Can I go about my daily routine without having to worry about when I need to plug it in again.

So in  a nutshell, 300 miles, no faster than 60 around town. (Realistically, 45-50)

[BrianTRice@gmail.com]

So in  a nutshell, 300 miles, no faster than 60 around town. (Realistically, 45-50)

As a V-Strom owner, 300 miles of range is also my sweet spot, but e.g. Zero's models top out at roughly 200 miles maximum given the latest 13kWh battery pack with (2.8kWh still?) power tank. That implies a 24kWh pack with attendant weight and price to go 300 miles.

For what it's worth, as an actual Zero user, the 100 miles of 55mph range (using a windshield) is fine with me. One can carry fast chargers to restore the charge and keep going. Even with one Elcon charger, I can do 250 miles in one day. I'm hoping to cover 400 miles per day with a charging upgrade soon.

Well, hopefully by the time your first project is done, your dream will be feasible to plan for. Good luck!

[Eco Mouse]

Well I heard AC motors are much more efficient. Are Zeros using AC motors? Also what's the deal with that huge rear sprocket? Why are there no major EV motorcycle manufacturer using a hub motor? seems to me they are losing a bit of efficiency going through a drive train. Even more so for the guys using a traditional gear box.

Can I pair up graphene super capacitors with batteries?

[BrianTRice@gmail.com]

Well I heard AC motors are much more efficient. Are Zeros using AC motors? Also what's the deal with that huge rear sprocket?

Zero uses a brushless AC motor with a Sevcon Gen4 controller that produces a rotating field using 3 phases of windings. It's very efficient for the design they care about: simple to operate and maintain, cheap to produce, and reliable. The controller can determine speed and torque very easily; it feels like magic and I prefer it on dirt.

Really, the only thing I'd evaluate is how much dual sport needs would shape your outlook. Personally, I'm tweaking the controller programming so a reverse mode is available to winch the bike out of an awkward downhill situation, and making do with the Zero platform as-is. This means a compromise on adventures but I just want to have a good time across the countryside and planning trip legs between RV parks (which have the best rural charge rates) already constrains that enough that I don't feel like pushing the design hard. Oh, I might make a lower guard for the belt.

Why are there no major EV motorcycle manufacturer using a hub motor? seems to me they are losing a bit of efficiency going through a drive train. Even more so for the guys using a traditional gear box.

There's a whole thread that dove into the hub motor topic and I do not care to get into it.

For a dual sport concern, chains are more resilient off-road than belts, but a hub motor means you don't have to transmit the torque across the swingarm. On the other hand, hub motors mean you transmit current and control signals across the swingarm. That does seem risky to me; I'd rather have to replace a belt or re-link a chain in the field than see high-current conductors fail from abrasion. Chains and belts are efficient enough.

Can I pair up graphene super capacitors with batteries?

Graphene supercapacitors are barely applied/purchasable in the real world yet; that would be its own research project to assemble them into a bank to use SAFELY. Plus, they'd only help if you could actually get power faster than the C-rate on Lithium ion batteries (full charge in ~1 hour).

[Eco Mouse]

Ok, I still need to understand the different motor wattage and what they will give me.

If I went with an 8kw motor, that could theoretically give me a higher top speed? But will it still drain my battery packs faster if was running within 50% of the motors peak capacity? Let's say that it was capable of 100mph, but I run typically 50 and under. It's that only drawing half of what is asking for and therefore more efficient to over build?

And what's the deal with 72v, 84v, and 96v options?

[BrianTRice@gmail.com]

I don't know what you're talking about, re: "eGrom". I can't find anything online.