So first of I searched the site and couldn't find the answer I need.
Bare with me I just started reading about changing the sprokets today, it seems like the fastest cheapest way to go is just to drop to 15t up front, is there any benifit to changing the rear instead..or aswell. Let me know.
faster acceleration and easier to do wheelies.
It's easier to change the front sprocket, as you can do it without changing chain length, generally. You can go down to 15, or 14 before you have problems with your chain. At that point, the front is as small as it goes, and you have to start increasing the rear sprocket size. +3 in the rear is worth -1 in the front.
JT has 16, 15, 14 and 39, 45 tooth sprockets on bikebandit (14/45 is 3.21 ratio, stock is 16/39 or 2.44, so there's a huge range there). The larger rear will probably require a new chain, or a few extra links.
Actually, 14/45 sounds like fun, but you'd be at 8500 RPM at 80mph. That could get old.