haha right. you might "ride" with cheetahs.. big deal. i can take out a stock 400ex and "ride" with some cheetahs.. but that doesnt mean im actually running with them.. 18's are for fuckin motocross bikes. banshees, with very few exceptions, are NOT motocross bikes. they are for duning, fast paced trail riding, and dragging.. and to be quite honest, i dont see any of those people using 18" tires. which bring me to my next point. why buy 18" tires just to have to compensate with huge gearing changes? that makes no sense. keep close to stock gearing and just use 20" tires. running 15/41 with 20" tires is damn near the same as running 17/41 with 18" tires except with 18" tires you lose ground clearance.. you obviously have no concept of gearing and tire relationships or youd know that your particular gearing and tire has NOTHING to do with you "riding" with cheetahs. i can run 25" tires and 13/44 gearing and be at the same gearing ratio as you.
so, yamahapowr.. just buy 20" tires and use what about 99.5% of the people on this forum do.