Tire sizes and re gearing???

[goonie]

I was wonder if since my 250r had 22's on if i switched and put 18's or 20's on would i have to change my sprocket size? And would i have to go bigger or smaller on the back and vis versa for the front sprockets???? Any help PPLEASE!!!!!!!

[dcreel]

Going to smaller diameter rear tires you would go up on the countershaft sprocket and down on the rear sprocket to compensate for the smaller diameter rear tires. A general rule of thumb is for every tooth you go up on the countershaft sprocket it equals 2 teeth smaller on the rear sprocket.

[WilliamJ]

You could try this little calculator.

http://home.earthlink.net/~gellett/mph.htm

[dcreel]

http://www.sprocketcalculator.com/

[Swinger]

I did some gearing and went way too extreme for what the motor actually can pull. Stay in your motors capabilities! I was hopeing for 100mph and got no powerband in 4th and 5th gear. Ha ha, Im an idiot though so went a little closer to stock and got better results. Still not 100mph but got my bands back. What are you trying to get to your original speed or you goin for something different?

[goonie]

Im just trying to go the same mph maybe a tad faster, but I like the torque too, I like to be able to rip up a hill and launch if the other side.

[goonie]

Thanks for the links guys :) definetly helped!!