14 tooth gear

Im probably going to run 15/39 as BlasterDude suggested. Thanks for all your help
 
I put a 14 on the front of mine and loved it. With the right mods it actually seems faster. On a stock engine I'm not so sure but a modded one a great improvement. I run 20" tires as well.
 
I have 20" tires and a 14/40 gearing, it works great for me, I ride in a lot of open areas and it gave me the top end I needed, although it could stand to have a 7th gear
 
why not run 15/39?

Why would you quote me when all I was saying what I run. If you want to know why I don't run 15/39 is because if you could find a 15 tooth front it wouldn't fit and a change of 1 tooth in front is comparable to 3 teeth in the rear. I myself didn't find the need to lower the # in the rear. But, if you are running this combo let us know how it's working for ya.
 
I'm currently running 14/38 gearing with 20" tires. This setup works great, lots of top end but still tonnes of torque. Even for a close to stock engine the 14T sprocket will work fine.