Determine your needs and find an appropriate donor bike.
Around town cruising? Commuter bike?
The donor bike was purchased for less than $500. We chose this one because it had enough room for the motor and batteries we were looking to use and this one had new tires as well as several other items that were recently replaced. There are many of these bikes around so replacement/conversion parts were not hard to find. I had looked at a Honda that would have been a better cosmetic project, but it was considered rare and I did not want to tear up a cool good running bike.
This is what the bike looks like new. Ours was not that pretty.
The only bad thing about it was it came with belt drive. Why not belt drive? We would like to run belt drive, but this did not allow the 4 to 1 ratio an electric bike needs to run correctly. Not enough sprocket choices. The same model does come in a chain drive so the conversion should be easy.
The bike has a few items that were heavy (steel chain covers and such) and will be changed out for newer lighter equipment as I can find them on EBAY.
Make sure you think about items like the speedometer and where you will mount a voltmeter. A Voltmeter? This will be your “gas gauge” by letting you know how much power is left in the batteries. Our speedometer was mechanical and ran off the front tire so it was not an issue. There are some newer bikes that have a digital run speedo.
The bikes weight:
Every ounce counts with battery power. Batteries and the motor weigh a bunch. Make sure the bike can handle it. Most of them can. Our bike was originally water cooled so we knew all of our equipment would weigh less than the original setup. We tried to reuse already installed mounts for the motor and battery racks. All of the covers are plastic. The tank will hide a lot of the electronics. After it was stripped, we weighed the empty bike and all of the items being installed. It looks like we may be able to get the bike under 400 pounds!