gear ratio on a 42 cc chainsaw powerd bike

HI! Im new to instructables and Im wondering what kind of ratio of sprocket i will need to mount a chainsaw engine on a 26 inch bike
i want to use pre existing bike sprockets that i can some how mount on the rear tire. ideas? i have the ability to use a mig/tig/oxy welders.
also what kind of/ size sprockets will i need to mount.

noahwinter357 (author) 1 year ago
I want to use bicycle sprockets. Like from a mountain bike
forgot to add the photo
Hi Ive built a few, and you need to get the ratio lower than you might think. for every meter the bike travels the engine needs to turn 6-8 times depending on the size of the engine. a good place to start would be a pocket bike gearbox they have a ratio of around 6 to one you can get them here
for around $45 and will bolt up to a Honda brush cutter engine FYI
If you have a look at this video near the end it has some info about the gear box and ratios needed to get the engine working through a 7 speed gearbox