(College project) Any advice on electric motorcycle conversions? I have to build one but have no idea where to start

[Syze00]

This is a class project for college and we have the frame of a Kawasaki chopper style (not a street bike) thats going to be painted and styled in a steampunk fashion once its done but I have to purchase a motor and control system for this.  My professor pitched the idea of the Netgain Hyper 9 IS (IS for integrated system) but that thing is a chunky boi.  I think its overkill but it has everything we could need. 

 

The main goals of the project is to build an electric street legal motorcycle that can hit 100 mph with the motor turning a sprocket to the gear like a standard motorcycle so I think hub motor wheels are out.  This will also be going to motor shows to support the school.  From my basic research into electric motors I have PMSM, SyRM, AFIPM, Brushed (which will probably get too hot) Induction and SRM.

 

I'm not even sure what I'm going to use to power this thing with.  Do I buy a pallet of LiPo or Li iOn batteries made for those hover boards and wire them up in series and parallel?  I have never owned or even been on a motorcycle before so I honestly don't know what is and isn't possible. We can throw some saddle bags on it to store batteries but I hate the fact I know nothing about this stuff.  I mean it will be pretty cool to learn it but I was hoping to see if anyone has any opinions on this. 

Thanks in advance for any advice.

[Dutch_Master]

Does it need to hit that 100mph mark instantly or eventually?   That's quite important for the power you need. To learn a bit more on electric vehicles, search YT for the Jerryrigeverything channel, he has a whole series of converting a 1990's Humvee from petrol (gas) to electric.

 

One bit of advise: keep the centre of gravity of the bike as low as you can. Batteries are heavy and so are electric motors. But said motors are considerably smaller then their combustion type equivalents for the same HP rating.

 

For everything else, there's Google. This is an educational project after all, we're not gonna hand you a ready-2-build plan, aren't we?

[Syze00]

1 minute ago, Dutch_Master said:

Does it need to hit that 100mph mark instantly or eventually?   That's quite important for the power you need. To learn a bit more on electric vehicles, search YT for the Jerryrigeverything channel, he has a whole series of converting a 1990's Humvee from petrol (gas) to electric.

 

One bit of advise: keep the centre of gravity of the bike as low as you can. Batteries are heavy and so are electric motors. But said motors are considerably smaller then their combustion type equivalents for the same HP rating.

 

For everything else, there's Google. This is an educational project after all, we're not gonna hand you a ready-2-build plan, aren't we?

Even with a plan thats 100%, the thing still needs to be built!  I don't expect it to go 100 instantly.  I think that would be a tad too dangerous.  I'm thinking that avg speed puttering around will be 50 mph but it needs to have the capability to hit 100 mph.  Also  It can't just hit it once then die on you with the batteries dead.  I just realized that I honestly don't even know what battery chemistry I'm gonna need.... 

[Yoinkerman]

This sounds very out of reach for your college class.  Are electric motorcycles even legal in your jurisdiction?

[Needfuldoer]

I assume you've already stumbled across Benjamin Nelson's DIY electric motorcycle content?

 

https://www.instructables.com/Build-Your-Own-ELECTRIC-MOTORCYCLE/

https://300mpg.org/projects/evcycle/

 

If you wanted to cheat the powertrain side, you could source everything you need (battery, motor, controls, charger, etc) from a totaled Zero motorcycle. Rich Rebuilds used a Zero drivetrain to electrify a hot rod. Packaging the Zero monolith battery might be a challenge in your frame, though.

 

 

[Sauron]

9 hours ago, Syze00 said:

I just realized that I honestly don't even know what battery chemistry I'm gonna need.... 

Li-ion has the best charge density but you can probably get away with something more crude for a university project, even if it only lasts a few dozen km it should be enough for demonstration purposes. I'd establish a weight limit for your battery first so you can design the rest of the motorcycle.

 

100mph is really fast, seems like a bit too much for a student project. Even testing it would be dangerous at those speeds on a diy build (as well as illegal on most roads). If I were you I'd start off shooting for something that can go 30mph/50kph, the speed limit in most urban areas. Once that works and seems safe enough you can take a look at making it more powerful.

[Syze00]

5 hours ago, Sauron said:

Li-ion has the best charge density but you can probably get away with something more crude for a university project, even if it only lasts a few dozen km it should be enough for demonstration purposes. I'd establish a weight limit for your battery first so you can design the rest of the motorcycle.

 

100mph is really fast, seems like a bit too much for a student project. Even testing it would be dangerous at those speeds on a diy build (as well as illegal on most roads). If I were you I'd start off shooting for something that can go 30mph/50kph, the speed limit in most urban areas. Once that works and seems safe enough you can take a look at making it more powerful.

I get that 100 mph is a high mark to hit, but I think thats why my professor set it.  TBH, he's using his own money to build this project.  He sold one of his cars and told us we have X amount of money to spend and gave us a goal.  I think its doable but god I wish I had more information on electric motor tech, battery chemistry and even knowing how to ride a motorcycle.  I'm really up the brown creek on this one.  I don't think his idea of slapping that Netgain 9 is going to work since that thing is too big, but maybe I'm wrong.  I just look at the pictures and see how big and heavy it is but I suppose it might be similar in weight if I consider how much the motor used to weigh and the fact we might not need a transmission.  The head of the mech dept has a passion for this stuff and thats why he's willing to spend his own money on certain projects.  One because it will help the school and 2, he can ride a super fast motorcycle at the end of the day.  We have the tools to pretty much manufacture anything.  We have carbon fiber printers, huge bridgeport style mills that are brand new, motorcycle lifts and soon a car lift. Thanks @Needfuldoer for the suggestions.  I will be watching that series and see about looking for a crashed zero if I can find one.

@Yoinkerman  We have to make it DOT compliant which has a few lighting laws, signal laws but a motorcycle is fairly easy to get done esp if you are a University and in Texas.  Just think, cars need tons of safety devices like seat belts, airbags, crumple zones but a motorcycle you just need some armor, a helmet and maybe a prayer or two.

[LogicalDrm]

-> Moved to Hobby Electronics

 

Sorry, but just adding electricity to something without it doesn't qualify as "tech".

[Triumph_Tech]

This is by no means impossible, but it seems strange.

1. Professor is personally bank rolling a potentially huge cost project.

2. Must reach 100 mph? Lets say you get a working prototype. Do you have access to a dyno? No one in their right mind would test ride such a thing with out MANY successful tests on static runs.

3. Must meet DOT standards? Motorcycles have many requirements for DOT certification and yes electric motorcycles have their own category and regulations.

4. It sounds like there is little experience in mechanical and electrical engineering.

 

That being all said there are 4 major parts to this. Chassis, battery, power train, and control. Your biggest enemy for an electric motorcycle is battery heat, and power train efficiency. Batteries require more than just hooking them up in series and off you go. You need a battery management system that monitors the charge and discharge of the batteries (extremely over simplification of a BMS). The batteries get super hot and so can the motor. Newest bikes that are coming out are starting to be liquid cooled as technology is improving in the field.

 

Unless you just rip apart and frankenstein a pre-existing electric motorcycle you have a lot that needs to be figured out.

[t0rbz]

Check out damien maguire on youtube. Nissan leaf ev motors are relatively cheap from wreckers, and he has open source designs that can handle the drivetrain side of things. batteries, your only real option for that kind of speed is lipo or lifepo4 cells and associated BMS, Ebikes also might get you there, companies like ASI (accelerated systems inc) have controllers in the few to many kw range. Guessing you need 15-25kw to hit that speed target with all the weight you will have. There are also many closed source projects that you can just buy to work with specific drivetrains as well like thunderstruck-ev.