I'm on my second edition of a scratch built eletric bike. The first setup was a sprocket bolted to the spokes with fabricated motor mount on the left side of the rear wheel. The system worked good on the premise the motor had low rolling resistance, so that when I wasn't using the motor, the bike could still be pedaled. The motor was a small 24volt - from a bike scooter - slow acceleration / slow speed. It wasn't quite geared right, the motor didn't spin up to speed and was working too hard. It was quite fun, but not enough torque or speed. (Top end was 16mph)
I'm currently working on Rev 2:
(Using a larger motor and gearing, better batteries.)
Bigger better motor 130 RPM 20:1 Gear ratio.- that is geared down to a low RPM - 24Volt. The motor doesn't spin by hand, and I need to consider using a freewheel between the Motor and the sproket that is fastened on the left rear tire. My motor has a shaft of 3/4" - Does anybody have any great suggestions on putting a freewheel in place?
My intention is to use a Freewheel ?stacked sproket? (Not sure the tech term) on the drive motor with a derailer so that I can use the gears.. just like you would if you were pedaling. This way I will have gears on both sides. Gears for my pedaling, and gears for the motor... (reasoning is that I have 2 young children that I tow behind me in a bike trailer) - Lower gear's for torque and hills are a requirement.