Picture of Easy DIY Electric Motorcycle Conversion
We started with a Honda Rebel junker and a dream - to make a practical, zero emissions vehicle for commuting in San Francisco. After consulting with some plans available online which required chopping the frame significantly, We decided to figure it out for ourselves. Armed with a basic metal shop, we methodically convert the Honda rebel 250 into a clean quiet bike in about a week. It is registered and insured in CA as a modified 250. (if the power system were 24V or less, no registration is required).

The old rebel rolling chassis provided us with many of the needed parts - wheels, tires, brakes, etc... which was a real bonus - but it also supplied us with many rusty, broken, stripped or missing parts. In fact, most of our difficulties were because of the old parts, not because of the conversion itself. Without these annoyances, the conversion would have taken about two and a half days.

With an onboard 48V charger and 3-prong wall plug hardwired on, recharging is easy anywhere there's a wall outlet. Charging time depends upon how depleted the batteries are, but usually they were topped off after 5-8 hours.

Step 1: Gather Parts, Tools and Materials

Picture of Gather Parts, Tools and Materials
We scored a blown Honda Rebel 250 on Craigslist for under $500. It had a blown engine, but included all the other parts needed to make the bike safe and street legal: Lights, brakes, wheels, shocks, etc... I had a set of 4 deep cycle batteries from previous projects. We purchased most of the other AC components from Electric Motorsport in Oakland and also consulted a set of plans from 21 Wheels. Ultimately we had to redesign many aspects of the project and develop our own solutions.

Honda Rebel 250 rolling chassis
Perm PMG-132 electric motor
(4) 12V 50Ah batteries in series
36V-72V PWM controller
5 k potentiometer (i.e. twist grip throttle)
48V AC charger
48 -12V down converter OR additional small 12V battery (for lights, signal and horn)
#4 welding cable and lugs
Custom sprockets

4" angle grinder (with cutting and grinding wheels)
Drill press
Metal band saw
Standard auto shop tools, wrenches
Heavy duty wire cutters / crimping tool

Honda Rebel service manual
Make Magazine Gear calculator (for choosing sprocket sizes)
EL Chopper ET builder's plans - outdated, but a great starting point
Friends who can help

TheTutor112 months ago
How fast does it go? How much did the total build cost?
andy.knote8 months ago

Step 10, wiring- You had 4- 12V batteries in series, could you not have tapped 1 battery for 12 volts? I've tapped 12 volts off one battery in a vehicle that used two 12V batteries in series for a 24Volt system...

Still a cool project.

andy.knote8 months ago

See, thats just cool. Nice work.

john henry10 months ago

I been wanting to do something like this for awhile thanks for the Guide!

I helped with a truck conversion in high school so I'm looking forward to doing all the work my self instead of hardly any.

udaymohan2 years ago
Out of curiosity would you not have been able to save considerable amount of weight if you had used lithium ion motorcycle batteries? Might even be able to get more connected and extend the range?
billbillt2 years ago
Juan422 years ago
criddifer5 years ago
you could put a car altanator with a toothed gear on the shaft with very little friction to turn it to charge the extra battery for the light and other normal eletronics on the bike and it should work
Think about it. Even you reduce all the losses associated with driving an alternator to zero,it's the vehicle's drive battery that would be providing any energy an alternator would provided. May as well use the added weight to increase battery capacity
Then how about adding a small diesel generator that can power the motor & load the battery? Instant hybrid motorcycle!
It will add only drag to the system. You can capture some energy through regenerative braking. You add a lot of complexity to your system though.
rebel diy2 years ago
sorry but i hade to comment on this it maby cleaner but it only goes 30 miles i can do 30 miles on my rebel wich is good old fashion petrol and i can get 180 to 200 miles on a tank
surly making the bike electric wouldnt be cost efective as the battarys will cost a lot when they stop holding a charge
it seams a bit pointless to me
bodo6 years ago
cant we use something like bicycle dinamo to get the bateries charged?
sparkyrust (author)  bodo6 years ago
Actually no. Anything which uses the bike's motion to capture energy is offset by the friction and drag created, so you actually lose more energy this way. Thnaks for the comments!
besides that, the dynamo would have to have it's power converted to DC to charge the battery.
Not that I'm saying a dynamo on an electric vehicle is something that's sensible, but most dynamos output DC without a need of outboard conversion
eron silva5 years ago
Dear friends, is it possible to use a car dynamo (without the AC converting part) as an electric motor for a bycicle conversion?
* I could get a used one almost for free;
* a car dynamo weights 12 kg, but some of it could be shaved off (unnecessary handles, installation arms, perhaps - maybe a half kilo or more...).
Yep, easy-peasy. You need a controller for a brushed motor to control the current to the rotor, and a separate controller for a brushless motor to control the current to the stator. The rotor will become magnetically saturated at between 4 and 6 amps (depending on the alternator) so that is a "set it and forget it" part after you measure the magnetic field for peak strength, then it's just a regular brushless motor that runs without drag when you turn off the power to the rotor. The "trick" to getting the most out of the motor is to adjust the rotor current to the lowest setting that still has a saturated rotor, and for that you need that Gauss meter. If you use one that reads low field strength you can still get the relative strength by just looking for how close you can get the meter without pegging it. The further away you have to move the meter the more powerful the magnetic field.
Look for a DC motor Treadmill. These have a fairly strong DC motor. You can find these on the curb on trash day that have little or no use on them.
Friends... I got the answer by myself @ www.4qd.co.uk/serv/appnotes/dynamo.html . Problem is, the article brings the sobering words "the cheapest way is not always the simplest". Check it out and count your blessings if you can afford US$500 for an etek motor, and what-not for the batteries... I will keep on looking for a cheap solution! Any suggestions are welcome (my requirements are humble: 50 Km/h, 24 km round trips, mostly level terrain) 


BruceKenobi4 years ago
Hi! I liked the instructable a lot as I am researching to embark in a similar adventure; however I found something contradicting: you mention in the parts list that you used a "Perm PMG-132 electric motor" and then mention "We purchased most of the other AC components from Electric Motorsport " but the Perm PMG-132 is a DC motor (I checked!) it is the Perm's edition of the E-Tek, both are DC motors, so you are doing a DC conversion, what AC parts did you need? just asking as I have been researching a lot on the AC vs DC motor debate and your instructable was a good "case-study" for a success story!
Since nobody has replied to your question, the AC parts are the stuff that connects to line power to recharge the batteries. Basically the battery charger is part of the bike instead of external as in many EV. It adds a bit to the weight but also makes charging as easy as finding an outlet while on the road. If you are just using the bike for commuting then you can replace the onboard charger with bigger batteries and a polarized charging plug.
i'd like to note (this instructable is a bit old but still meaningful) that if you're to do this conversion, you have to find motorcycle that uses chain drive. using a belt drive motorcycle will result in not being able to adjust the chain tension as it stretches, prematurely wearing out your chain and sprockets.
Could you use a shaft driven motorcycle? Those dont need to be tightened, all you need is oil for lubrication.
Calorie6 years ago
The zip wraps do concern me. During a wreck the plastic will stretch and break the locking tabs on the zip ties. I pick through wrecked cars at junk yards, and I've seen batteries where they shouldn't be.
sparkyrust (author)  Calorie6 years ago
That's a good concern, and one I considered. Ultimately I weighed all the aspects of those zipties vs. metal, which I had in the original design. The weight savings is huge, the ties are remarkably strong, and the batteries are wedged in so tight, with lots of thick battery cabling too boot, that they don't come out easily, even when I want them out. And with a top speed of about 35-40 mph, if I'm in a wreck that has enough force to knock those batteries out of whack.... well then I've probably got a lot of problems to deal with. Thanks again for the comments, Best.
That's true. Your going to have problems at 40 mph. But it's best to minimize them. Remeber the important equation is:

Force = Mass + Acceleration

The best way to think of it is that a static force has no change in acceleration. But even a slight difference in acceleration leads to a huge change in force. You can hang on a tree with shoe strings, but the moment you try to swing into the local swimmin' hole you'll find yourself in a great deal of pain.

That change in acceleration is the important part. That's why bicycle and motor helmets seem hard, but in reality they slightly slow the rate of acceleration.

Just being a math and safety dork all at once. I've cracked three helmets with nary a car in sight. All my fault :-(
Force = Mass X Acceleration.
... um.. mr. math and safety dork (i am a bit of one myself)...

force = mass "X" acceleration...

maybe hop off your soapbox and check your formulas...

raju4love3 years ago
hey its a good job done by you
i need some help from you because you are a expert
please do me some help
i want some knowledge about this so please contact me at my mail id please


pls please do me this help please please
PTooTi3 years ago
Wahhh! I used to have a Rebel hard to believe it was almost 25 years ago nice little bike and the conversion looks kool too how fast/far can you travel on it?
nepemex3 years ago
great job i wish yo can put more instructions about how connect the controller and the engine, and whta happen with the Throttle?(how it will work ?)
in resume :can you put a BLOG and a STEP by STEP method?
(under our own risk)
thanks! great job
deepsea53 years ago
sparkyrust; thanks for posting this!

For those who have done this conversion: have you tried the Optima Blue Top battery; and converting headlamp/tail lamp/directional lamps to LED bulbs?
Bosun Rick4 years ago
Has anyone considered using a HYDRAULIC (think Hydrostatic) drive with an Electric motor?

No drive alignment issues, just hoses, a pump and the Hydro motor

See www.hydraulicinnovations.com for details. Their unit is larger and heavier duty than this project would require, but the concept would be the same.
astonehouse4 years ago
Hey guys here is just a little comment to think about. Hydrogen has been the "fuel of the future" for 45 years. And always will be. Forget your hydrogen powered whatever. There is no feasible way to, A; Compress the hydrogen enough to get a reasonable energy return per fill up, and B: no way to completely seal up any container of hydrogen. Tiny slippery little molecules just will not stay in the jar.And C: Anyone remember Lakehurst Field and the Hindenburg? A pleasant fantasy, a car the just makes water when you drive. Time to wake up now
Hindenburg disaster was not caused by hydrogen. The myth that it was has been tackled and disproven many times over. It was a combination of the chemica treatment it got and the aluminium covering. If hydrogen was burning in the video, we would not have seen the flames and smoke that we did. The hydrogen can be seen burning after the fact, but that was long after the accelerated due to the chemical treatment on the blimp.
Im wondering whatever happened to Hondas car Clarity that ran on hydrogen :P
XOIIO4 years ago
Man, you gotta psot a video going 0 to top speed, that bikle looks sick
balun4 years ago
great work....
rc jedi4 years ago
i fly r/c planes, the prices of lipo batteries has come down dramatically. I
get mine from china.
i fly 24 volt brushless motor setups, these batteries can offer much greater power to weight ratio. They do require special chargers and cannot be discharged below 3 volts per cell. but lead acid shouldn't be deep cycled either. just an option.
i always use paypal, especially overseas orders.
Hubiewan5 years ago
Hubiewan asks:
Why not use the original gas tank to store the electronics, thus keeping it looking like a regular bike?
i agree because then you could fit the other batteries up front and then you could have real side bags for runs to the store and could store the charging cord in the gas flap
I want people to look at mine and say, "That's not a regular bike." Therefore, when I make my ebike, the design is going to be based on the components it uses, which is how the design of gasoline motorcycles arose.
anjimehra5 years ago
Whatll be a good ratio for a bike weighing app. 120 kgs + a 70 kg rider?
bennelson6 years ago
I built a similar project last summer. You can see my basic web page about it at Ben's Electric Motorcycle

Mine kept the gas tank for looks, and it works as a cover for the charger.

Great job on yours Sparkyrust!

Heres the thing about electric.In the wrong hands it more dangerous to the environment. People will not recycle batterys but toss them in landfills. Electric is only good in the hands of private builders like you and me . People who know where to take them/use them and recharge them Right. It not worth the money to invest in electric bikes/cars till we get better Battery cells which can produce the power we need to make the vehicles run a longer distance at leat 250 miles.Hydrogen is the wave of the future.
sojakai vistal5 years ago
I have a friend who loves going to the landfills and getting the car batteries that people leave. Puts them on a desulfator and brings them back to life. He gets a truly dead battery from time to time, but its pretty rare.
Cool video. How much did it cost, and what is the range and charge time?
I also have a Ben's Electric Motorcycle

sparkyrust (author)  bennelson6 years ago
The guys at Electric Motorsport in Oakland have a few bike designs that use the gas cap on the tank as a cover for the charger too. It's a ironic twist that is always good for a chuckle. Thanks for the Comments. Cheers!
you wouldn't power your toaster on gasoline, would you?

great argument!
...I would. I already do my blender that way...
well, i don't like my toast to smell like gasoline...
JTurner3856 years ago
Is it possible to get all of the needed parts for the conversion from a used 48v golf cart? The thing is, I am in Mexico and the sources for most of the parts are in the US. I can have them shipped but it does cost a lot and i am worried about customs fees. Any suggestions?
alloqba6 years ago
Hello! First of all - awesome conversion, although I would have left the gas tank just to look nicer :) Next - I have a question about battery: After half a year of using this moto - do you see drastically battery life shortening? Are they just standard ones - used for cars, or some kind of deep-cycle or else? Finally - how can you compare acceleration of this motorcycle to others 250cc or 125cc gasoline motorcycles? And how comfortable it is to commute in town using this vehicle? (I mean - if you are continuously overtaken by other cars, or you are just "normal" user of the street)
Uncle Kudzu6 years ago
i wonder if something like that NuVinci CVP hub would increase efficiency on a project like this, or is the simplicity of just two sprockets an advantage in some way?
Arayas6 years ago
Hey guys looks it turned out really good -excellent project! I've been considering converting a bike for my senior project. Any chance you could post a rough estimation of the costs? Also, I would love any info you could provide on where one might be able to look up / purchase the batteries...? Congratulations again and thanks in advance! -Ian
Same Here!! Im just a sophomore (in college) but am trying to get some ideas on what i should do for my Senior project. (kinda get a head start)
Inksp0t6 years ago
I've been reading about old school hard tail minibikes lately. Many of those rebuilds use a torque converter (like the Comet TAV2) to increase the torque and top speed of small 3.5 to 6.5 horsepower horizontal shaft engines. I knew the goal here is to use electric, so my question is TAV2 or similar torque converter be used on the motorcycle conversion? I could be wrong but it seems to me that would increase battery life by decreasing load on the motor.... What are your thoughts?
Belt type torque converters are very lossy due to friction of the belt against the variable sheaves. Not advisable for use with an electric drive system. If you have a sufficiently powerful electric motor and plan your gear ratios such that the motor is running close to max RPM at the fastest speed you require, no gear ratio variation is required.
teamcoltra6 years ago
Awesome instructable... have you thought of remounting the gas tank and using it as a storage compartment (like a glove box) or to hold your extra electronics and stuff?
Calorie6 years ago
Thank you for wearing safety gear. It's a rare thing. I'm especially irked by people who don't wear proper clothes and gloves. The face shield for grinding is such a basic but good idea. It's a couple of bucks at harbor freight, and well worth it. I cannot tell you how many times I've had bit of molten metal launch to my face and that basic shield save me. Unfortunately it always seems like I end up in an awkward position with the grinder. I think the last fun I had with the grinder (Harbor Freight as well) was grinding off a set of reinforcements on an engine block. It was a long job, and I wasn't wearing any sort of cap to cover my head. Sure I was wearing my shield, mask and goggles just to be sure. But an errant spark/molten metal landed on the top of my head. It really hurt. I think people should remember that all of those sparks from welding and grinding are just airborne molten metal. And welding emits a huge amount of UV light. Nice job on the safety
sparkyrust (author)  Calorie6 years ago
Hey Calorie- Thanks for the comments. I try to remember to be safe, especially with my eyes. My hands and arms can get a bit torn up, but not the peepers. Safety Third! -SparkyRust
wryce6 years ago
Did you consider mating the electric motor to the motorcycle transmission?
sparkyrust (author)  wryce6 years ago
Hi- I've heard of a few efforts to do this - the theory is that you can take advantage of the gearing to get more speed, etc... It isn't possible in many drive-train config's, but some do allow for it. Most electric vehicles avoid the transmission (and all it's complexity) and instead opt for a single gear, which usually supplies enough torque to replicate the traditional gears. The best part of electric is how few moving parts are needed. Compared to the hundreds, or even thousands of moving parts in a traditional engine/transmission, most electric vehicle drive-trains have only one single moving part - the rotation motor shaft. I often stop and marvel at the simplicity of electric. Thanks for the question!
Thank you
LinuxH4x0r6 years ago
Gomi style?
sparkyrust (author)  LinuxH4x0r6 years ago

Gomi Style is the name of my web-based DIY lifestyle and design series. Gomi is a Japanese word for garbage, and for some reason, it stuck. Feel free to check out all the videos at http://www.gomistyle.com
I thought it looked familiar! Great work! Keep posting more stuff on ibles for everyone to enjoy. Thanks!
Love your article, please post more! I know you have a regular job and all but if you have some spare time can you post your performance stats? How far traveled on one charge, top speed, how suitable for all weather driving? tnx
sparkyrust (author)  KungFuChicken6 years ago
Hey KFC- The stats were always a bit below expectations, and never the same twice. I generally hit a top speed of 35-40 MPH, Range was between 15-25 miles per charge, and I never took it out in wet weather, although it still got hit with dirt and moisture during normal driving and seemed OK. Thanks for the questions. Keep 'em coming...
Andruha11236 years ago
why ac motor?
what i want to know...
Regenerative braking and higher efficiency are generally the advantages of an AC motor. Don't know about this specific kit though.
ok, but this bike has regular disk brakes ac motors need AC to run, right?
Yes. AC motors use an alternating current to run. But the differences actually go deeper than that. If you've heard the term "brushed DC" motor, as opposed to a brushless motor, you know what I'm talking about. If you don't, I suggest you read up on different motor types. A certain kind of AC motor, when energized but made to spin by an outside force (say, the momentum of your bike moving forward), will take that energy and convert it back into electricity via the same mechanism that a generator does. Because you're converting the energy, less and less of it is kinetic (2nd law of thermo...) so the net effect is that your bike slows down and you capture that energy in your batteries. ... but only if your motor controller has that ability. Otherwise, it would probably just disconnect the leads and leave the braking up to the brakes. You still need regular brakes though, because regen braking will not stop you on a dime... maybe a very large dime, but not a regular-sized one. It all really depends on how you drive/ride. Lots of stops vs. long stretches...
ac motors need an energized field, and they don't have magnets, so they should be LESS efficient yes, i know about brush less motors, the ones inside computer fans
I don't know HOW they're more efficient, they just are (because the intarwebz tole meh :-D ) although now I'm inclined to look it up meself.... I think it has something to do with the torque curve being more consistent, or the lack of energy loss from the brushes...
AC motors are more efficient at generating power, i know that
By that logic, they should also be more efficient at generating motion from electric energy... Look, I dun want to argue, so if you really want me to, just say so, and I will actually research the reasons why and post them...
no, it's okay
but battery store energy in dc, don't they?
Yes, but you have an AC Speed controller, which is essentially a really cool/expensive Inverter with a variable frequency thingy...
sparkyrust (author)  Andruha11236 years ago
Ooops. My mistake. I often use "AC" as shorthand when I mean the general term "electric". The motor that I chose for this project is indeed a DC motor, not an AC motor. Thanks for the comments, and keeping me accurate!
it's not an AC motor:

from: http://www.thunderstruck-ev.com/perm132.htm

The PMG 132 is a "pancake" style, axiall gap, neutrally timed, brushed, permanent magnet DC motor manufactured by Perm Motor in Germany.

It's high power, high efficiency and small size make it a good choice for small electric vehicles, motorcycles, electrathons, generators, go-karts and robots.
I was wondering if it would not be more economical to use a a AC motor with a inverter and a AC dimmer switch rigged for a throttle?
sparkyrust (author)  KungFuChicken6 years ago
I'm not too sure about the setup you suggest. I think the inverter step would result in loss of energy, leading to lower, not higher, efficiency. If you ever give it a shot, let me know how it goes. Cheers!
Kapua6 years ago
Hey sparkyrust, just out of curiousity, rather then using four 50Ah batteries, couldnt you just use two 100Ah batteries?
sparkyrust (author)  Kapua6 years ago
Hi Kapua- The bike runs at 48v (4 x 12v). Your suggestion could be set up as a 24 v @ 100 Ah system, but it would likely not have enough torque to be useful. Also, I had these 4 used batteries around my shop already. I eventually replaced them with 4 smaller 50 Ah batteries, but got roughly the same results. I saved a bunch of weight, but has less energy storage.
sparkyrust (author) 6 years ago
Thanks to everyone who posted regarding this Instructable. As I stated in step #1, the Bidwell plans were a great inspiration for this project, but not very useful as a step-by-step guide. (The Instructable contains 2 links to the original plans, so clearly I'm acknowledging them). However, almost every step had to be re-designed from scratch based on my preferences and the parts that were available. In reality I received more design input from the folks at Electric MotorSport and my fabricator than from the Bidwell plans. Another way of looking at this: Bidwell wants to sell copies of his plans. Perhaps the popularity of my project (almost 225,000 views) has created a demand for the Bidwell plans, and he appreciates all the publicity and marketing that I have provided free of charge. Just a thought... Thanks again!
tchiseen6 years ago
I like this mod a lot. Nice work!
woahhhh, i have to do this someday...
we should build a 2 wheel drive motorcycle with electric motors you could direct drive the wheels
firehazrd6 years ago
This project rules! I have been wanting to do this for a while. It seems like a good way to learn about EV conversions. I even have a lead on a free 70's honda junker! Good job. Can't wait to start the teardown.