We based the design off of Eric Peltzer's Electric Bicycle. We modified the design to take into account a few major differences. We didn't want to weld anything, we wanted it to be cheaper, and we have access to a waterjet cutter.
Brian purchased a XYD-13 motor kit, which is a 600W motor that normally goes on a Currie Electric scooter. It came with a speed controller, and we had an option for a twist grip, or a thumb control. We also ordered a shaft, bearings, etc from McMaster Carr, and a small set of 10Ah batteries and charger. If he doesn't get enough range on the bike, the plan is to upgrade the batteries.
The motor came with an excellent one-way clutch built into the sprocket. We decided to keep this, which allows the motor pulley to freewheel while the bike is being pedaled.
Last weekend, after we had waterjet out the motor assembly frame, we spent a few hours assembling:
Full Gallery Link
The motor assembly
Preparing the output scprocket
Mounting the output sprocket
The fruits of the days efforts
- modify and mount the smaller pulley
- get shorter bolts for the output sprocket
- find and mount the bike rack to hold everything up
- install the batteries, controller, and thumb control