Joined: Jul 2007
Posts: 126
Likes: 0
From: San Francisco, CA, USA
Bikes: Dahon 2007 Cadenza, 2006 Speed Pro, 2005 Helios SL, 2004 Roo El, Minimoto Electric Bike, USPD Currie Electro Drive Electric Bike, Schwinn Scooter
Hello GeoKrpan, below are the answers to your questions:
1. The chain is not an ordinary bicycle chain. It is called #25 chain.
2. It has a freewheel and it is not the ones used on BMX bikes.
3. The gear on the motor is 11 teeth.
4. The gear on the wheel is 54 teeth.
Also, there is a gear box in between the motor and the wheel. Therefore, you cannot calculate the ratio like the bicycle gear ratio.
Lastly, if your intenion is try to built or copy the Currie's left gear one, than you cannot because you need a unique gearbox. Technically you can, but you need to have 10 teeth for the motor and 120 or more teeth for the wheel in addition to the freewheel.