i know this will sound crazy but i'm using a modified starter motor from a car. its a bosch starter motor 800 watts. with the solenoid taken off. the reason i have specific sprocket dimensions is because it will have to fit in the housing of the motor as i cannot take this off because it holds the front bearing in place. i'm not sure of the size of chain all i know is its a normal bicycle chain. i know there will be a chance the chain wont take the torque but i will try it this way first and I'll just be carefull not to apply too much torque. thanks for your reply. any ideas on my question.