Instructables

Easy DIY Electric Motorcycle Conversion

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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.

 
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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.

BASIC PARTS LIST
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

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

RESOURCES
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

udaymohan8 months 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?
billbillt8 months ago
great
Juan429 months ago
thanks
criddifer4 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 diy1 year 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
bodo4 years ago
cant we use something like bicycle dinamo to get the bateries charged?
sparkyrust (author)  bodo4 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 silva4 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) 

 

BruceKenobi2 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.
Calorie5 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)  Calorie5 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...

-CW
raju4love2 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

raju4love1u@gmail.com


pls please do me this help please please
PTooTi2 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?
nepemex2 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 ?)
as well as WHAT HAPPEN WITH THE BRAKES?
in resume :can you put a BLOG and a STEP by STEP method?
(under our own risk)
thanks! great job
deepsea52 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 Rick2 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.
astonehouse2 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
XOIIO2 years ago
Man, you gotta psot a video going 0 to top speed, that bikle looks sick
balun2 years ago
great work....
rc jedi2 years ago
i fly r/c planes, the prices of lipo batteries has come down dramatically. I
get mine from china.
http://www.hobbyking.com/hobbyking/store/uh_listCategoriesAndProducts.asp?catname=20C+Discharge&idCategory=239&ParentCat=85
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.
Hubiewan4 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.
anjimehra4 years ago
Hi
Whatll be a good ratio for a bike weighing app. 120 kgs + a 70 kg rider?
Anji
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