If I upgear my speedfight will it be much slower from a standing start, also if I rebore from 50-80cc will this be any faster than the 100 or would it be better with a bored out 100 to 120 can you help adam bike doctor
cheers chris, the balance seems ok pulling from lights, fast but has lost 10mph off top speed, can the belt be tightened or does it have to be a new one? then perhaps a bigger carb will push her to 60 or more?
andre
August 2007
With gearing if you want higher top speed then you will lose a little acceleration and vice versa, just find the right balance. As far as I know they are a chrome bore and cannot be "bored out" Big bore kits {a replacement cyclinder} are your best option. Even if you could bore one out have you tried getting a piston the correct size, is there enough lining on the cylinder etc.