what chain do you run?

i made 1 call to jeff at z1e for the solution. thanks jeff.

The calculation isn't that bad. If you take half the tooth count for the front and rear sprockets, add the length between the top centers of the two sprockets times 2 and divided by 5/8 or 3/4 (depending on chain). All rounded up to an even link count. This is accurate enough for determining chain length.

Using some high school trigonometry (remember Pythagoras?). All you need is the two sprocket sizes and the distance between the output shaft and rear axle centers (with the rear axle at the furthest forward point).

I use a Tsubaki Sigma chain that was special ordered for me by Jeff at Z1. I decided to go with the strongest chain I could find when I converted my GPZ1150 from a 630 to a 530 chain.