This is now a not-so-quick hack based on Eric Clark's Gear Calculator which is based on Rob Glover's Gear Calculator. Both of those are much better than this. I only wrote this one because some tubby, buddha looking guy needed a primary reduction field to do motorcycle gears, and he'd rather put in sprocket teeth number instead of a decimal ratio. If you have any other suggestions please email me.

If you want to add other bikes and you have all the info click here

Default values are for a 2003 FZ-1 cause thats what I own.