Donor Bike & De-ICE-ing
Okay, okay, if you want to get really technical, I didn’t “Build” an electric motorcycle from scratch. It is a CONVERSION. The main reason is for legal, insurance, and registration reasons. By taking an existing cycle and converting it, it already has a VIN, is the the computer system of your insurance company, and makes it easy to register. You can also get an older bike with a bad engine for less money than you would pay new for just a pile of parts like wheels, rims, handle-bars, etc. (If you really wanted to build a custom cycle from scratch, GO FOR IT! Just make sure you follow the letter of the law and meet all safety and construction requirements from local, regional, and federal transportation authorities!)
To start off, you are going to look for a “Glider” or ”Donor Bike”. You may already have something that’s been sitting around with a bad engine or transmission. Otherwise start looking for your cycle. You may want to check out Craigslist, the local newspaper classifieds, or stop and see every motorcycle for sale on the side of the road.
Besides just overall style and finding something that fits your budget, here’s what to look for in the donor bike.
OVERALL GOOD CONDITION
It might sound obvious, but get something that’s in fairly good condition. You want to do a conversion, not a restoration! Make sure the turn signals and headlight work. The horn should work. It shouldn’t be all rusted out. Get something that looks nice enough and will be fun to ride. If you happen to be somebody who regularly builds custom motorcycles and restorations, just ignore what I said. Go hog-wild instead. I do have to admit that the cycle I bought to convert to electric was not in very good shape. The price was right though. In the end, fixing all the little things on it took a fair amount of time and work. Looking back on it now, I would have preferred to spend a little more money and and have had fewer things to fix.
SAVE MONEY WITH A BAD ENGINE OR TRANSMISSION
In this conversion, the original engine and transmission are NOT used. If you buy a motorcycle that is in pretty good condition OTHER than a bad engine or transmission, you might be able to get a really good deal on it. Just make sure to keep the engine and transmission with for a while to confirm proper registration.
SAVE MONEY WITH A GOOD ENGINE AND TRANSMISSION
If you choose to buy a cycle in good running condition, make sure to carefully remove the engine and transmission. Keep all the parts together, label everything, and keep it out of the weather. Sell the engine and tranny to make some money back on the purchase of the cycle.
DRIVESHAFT, BELT-DRIVE, OR CHAIN
Most motorcycles are driven by a chain, but some use a belt or even a driveshaft. Get a donor bike with a chain. This will give you the most flexibilty and efficiency. Chains are cheap, don’t slip, and are easy to change gear ratios by swapping out an inexpensive sprocket. Electric motorcycles CAN be built with a belt or driveshaft, but it is more of an advanced project and has other considerations.
BATTERY AND MOTOR SPACE
You will want a cycle with enough room in its guts for the motor and batteries. A too-small cycle will limit where you can put the motor and batteries, and how many batteries will fit. An extremely large cycle gives you plenty of room, but the frame may become heavy quickly. Popular choices include sport bikes and medium-size standard cycles.
Sport bikes typically have an aluminum frame (light-weight) and it is shaped with two supports over the engine, and two under it. This gives you a “box” to mount your batteries. Sport bikes also usually have some sort of plastic fairing over the engine. After conversion to electric, you can put the fairing back on, and look almost stock.
A medium-size “standard” will have two frame supports under the engine, which can be re-used as a base or tray for mounting the batteries. You will most likely want to avoid any cycle that has a single piece of frame above or below the engine. It just makes it more difficult to find a way to mount the batteries. You can always fabricate something custom, but it’s best to start with a solid foundation.
GET THE BOOK
Most cycles have a mechanics repair manual available for them. You might be familiar with the Haynes or Chilton’s brands for car repair. Find the book for your cycle. Although it won’t cover the new custom electric system, it will tell you how to fix your brakes, align the chain, painting tips, general repair and maintenance, and have plenty of other useful information.
Once you have your donor bike, you need to De-ICE it. ICE stands for Internal Combustion Engine. You’ll be removing the engine, the transmission, and anything else related to that system. That includes the gas tank, the exhaust pipes, and a radiator if it has one. Remove these parts carefully, so you can re-sell them.
You will want to know where to put the electric motor for the conversion. The easiest way to do that is simply to put the electric motor exactly where the output shaft of the transmission was. Locate where the chain goes to on the transmission end and mark that location on the frame. Use a wax pencil or silver marker with a speed square to put a mark on the frame both vertically and horizontally from the output shaft of the transmission. You will later use these marks to position the electric motor.
The next step is to get and install the electric motor.