I have an '86 250r and want more low end for MX racing, my friend has an R, its got full laegar chassis, and a 300 kit, he runs national Open A and is running a 14-36 ratio, while stock is 13-38 I think. I was pretty sure that going down in the front to a 12 boost low end, but he said that going up in front to a 14 and down in back boosts low end. Which is it? Thanks

 

Dropping down a tooth on the counter sprocket or increasing the rear sprocket size will increase low-end; going higher on the counter sprocket and lower on the rear sprocket will provide higher top speed.

Keep in mind that if you run a smaller counter sprocket, you will lose top speed if that is of any importance to you.

mike
phx,az

 

If that is where he is racing, he has his sprockets that way because his machine is probably wicked fast, and he need is better off with more through the gears