Electric Motorcycle Conversion

Few, if any, electric vehicles sold today can ride on the road, but you could be one of the first people on your block to get one! How? You can actually convert your own gas-powered motorcycle to an electric vehicle! It’s certainly an involved project, but if you’re up to the task, it’s worth the rewards. Here’s a guide to converting your existing gas-powered motorcycle to an electric-powered bike!

BENEFITS for the environment: Electric motorcycles are simply cleaner for the environment. They contribute fewer carbon emissions, fewer hydrocarbons, and less noise pollution than a gas-powered motorcycle.¹

BENEFITS for your convenience: Don’t bother taking all those trips to the gas station when you can charge your motorcycle by plugging it into the wall. Also, electric motors operate relatively silently, which is nice for preserving your hearing and avoiding conflicts with neighbors about how noisy your motorcycle is.²

BENEFITS for your wallet: Although the initial investment is steep, you’ll save much more avoiding gas money and costly repairs over the lifetime of the motorcycle.³

Cost: High
The cheapest motorcycle conversion project out there is $1000, and that doesn’t even include the cost of tools.⁴

Time and effort: High
This project not only takes a lot of time and effort, but it requires a strong familiarity with the parts of a motorcycle, electrical circuitry, and metalworking. Because every motorcycle is different, this guide can only act as an outline of the broad steps involved in an electric conversion of a motorcycle

Materials:
Gas-Powered Motorcycle
Electric Motor
Rechargeable Batteries
Motor Controller
Twist Grip Throttle
Battery Charger
High-Current Switch/Contactor
High-Current Fuse
Large Gear Ratio⁵
Charger
DC/DC Converter
Battery Cable and Connectors
E-meter
12 GA wires
Heat Shrink Tubing
Electrical Tape
Wire Wrap
Socket Set
Screw Drivers
Wire Stripper
Volt Meter
Metal Grinder
Crimper⁶
½” angle iron⁷
Multimeter⁸

Directions:

1. Get the Motorcycle:
   • If you don’t already have a used motorcycle, you can easily find a used bike online. Although the motor doesn’t have to work anymore, make sure that the frame, suspension, wheels, bearings, and brakes are still in good working order.⁹ Once you know what kind of motorcycle you have, find or buy the owner’s instruction manual or wiring diagram.¹⁰
   • When choosing a motorcycle, keep in mind the difference between a chain drive and a shift drive. A chain drive is more efficient and has a better range, but a shaft drive requires almost no maintenance.¹¹
2. Strip the Frame: Before you start disassembling the motorcycle, be sure to get all the gas out of the motorcycle. Using the metal grinder, remove the engine, gas tank, transmission, engine mounts and pads, and any other part that supports this gas-powered system.¹² Save any nuts, bolts, washers, and screws.¹³ If the bike is particularly degraded, sand away the rust and paint the bike again.¹⁴
3. Planning Your Bike:
   • Decide how fast you want the bike to go and how long the battery needs to be charged. You’ll need to use the instruction manual and the wiring diagram to figure out the capacity of your motorcycle. Keep in mind you’ll need a higher voltage to power a shaft drive motorcycle.
   • All other aspects being equal, a higher voltage system lowers the motorcycle’s range and takes up more space to carry, making it harder to fit onto your bike, but allows for a high-enough speed to go on the freeway.¹⁵
   • If it’s too complicated to plan out what goes together, consider getting an electric motorcycle conversion kit. They’re probably more expensive than what you could find individually used, but you can probably save money that would have been wasted on unusable or incompatible parts. Here’s a website with a few kits, including some with wiring kits.
     
4. Mount the Batteries:
   • a. Decide where you want to mount the batteries. To help you see how everything will fit, trace and cut out cardboard outlines of the batteries and motor. Ideally, you’ll want the batteries mounted in the center lower to the ground, since this’ll make the motorcycle easier to turn.¹⁶
   • b. If the batteries won’t fit with the motor in the now-empty engine compartment, you’ll need to weld some metal trays to hold your batteries. Using the ½” angle iron, weld some battery mounts that will fit the batteries snugly but will allow them to be taken out and replaced.¹⁷
5. Mount the Motor:
   • To install a drive shaft or drive chain suitable for your bike’s speed and power, do a few calculations to figure out the ratio you’ll need for the motor to work maximize performance within the speed and power range you want.
     • For a great gear calculator for a drive chain, try this gear calculator.
     • For a great drive shaft calculator, try this website.
   • If you can, try to mount the motor in the exact same spot where the old motor used to be. Fitting it in the same place is best because everything should already be aligned.¹⁸
   • If the new motor won’t fit in the engine compartment, you’ll have to mount it into the swing arm itself. Remove the swing arm from the motorcycle frame if you haven’t already. Trace and cut out an area in the swing arm where the motor can fit tightly.¹⁹ Using a similar technique as with the battery mount, weld a semi-circle mount with bolt holes to cover and secure the motor to the swing arm.²⁰
6. Mount the Controller, Main Contactor, Throttle, and Charger:
   • Mount the controller in an easy-to-reach and well-ventilated place, since it can easily get overheated. For step-by-step instructions from your specific controller’s manufacturer, try this website
   • Mount the contactor next to the other somewhere in between the controller and the fuse so that it can be wired to both of these as well as the rest of the bike’s electrical system.
   • Use the multimeter to test the three wires – red, brown, and black – from the throttle. Connect the two wires with between 0 and 5k ohms of resistance to the controller. Connect the black wire to the contactor.²¹
     d. Mount the charger next to the batteries, making sure to allow easy access so you can easily charge your motorcycle. Using a 110 V AC charge would probably be the most practical, since you can just plug it into your house.²²
     
7. Wire Everything Together: Now you can finally connect everything together! In general, you’ll need to wire the batteries in series and connect the throttle, motor, and contactor to the controller.²³ You’ll have to do your own calculations based on the power requirements of your specific materials, but here’s a few wiring examples to show you how you could wire everything up:
   • 
   • 
     
8. Congratulations! You now have an electric motorcycle!