I am building a custom bike open belt primary how do i know how many teeth i need on the rear drive belt?

What kind of frame? The pulley size really only causes a difference of a few teeth.


If you are building on an aftermarket frame,the maker of that frame should be able to tell you what belt to use.


If its a stock (factory) H.D. frame, the final drive would be the same as before. Your primary drive does not change the length of your final drive belt.


As one poster said , you may just have to measure,if you've got the trani in the bike and you've got the rear wheel ,you can run a soft tape measure from pulley to pulley, get the measurement and compare it to a belt you have access to.

I am building a custom bike open belt primary how do i know how many teeth i need on the rear drive belt?
what is wrong with you lol
Reply:well i couldnt tell u but i can tell u that open belt drive is goin to make ur insurance higher for some reason insurances companies dont like open belt drives
Reply:wrap a tape measure around both sprockets take the measurement with you to a local bike shop and find the belt you need that way
Reply:the teeth / belts are grooves per inch ..mearsure the amount of teeth on the sprocket that are contained in 1 inch
Reply:Find the ratio of your stock primary drive by dividing the number of teeth on the clutch sprocket by the number of teeth on the engine sprocket. Next take your new belt drive set up, same thing divide the number of teeth on the clutch pulley by the number of teeth on the engine pulley. IF the ratio is the same there will be no need to alter the size of the rear belt drive pulley, UNLESS you want to. IF the new ratio is higher or lower you could alter the size of the front or rear final drive pulleys to regain the stock overall ratio.
Reply:depends what the primary has....then adjust that to what you want to do....


more outta the hole, or top end, or stay stock......