Maybe somebody can help me! After munching my stock Z tires (Dunlop 20-10-9 size) I have a difficult decision to make. ITP makes the lightweight XCR 20-11-9 for 4-stroke machines that will be a great improvement over stock, but, they also make the XCT 22-11-9 that are taller for more ground clearance that will help in the trails that I run. I could drop down a tooth on the countershaft to compensate with the taller tires but don't know if that is the best way to go. Any suggestions?