I have an 06' 636 with a k&n and the jumper mod, and until now it was back and forth on winning between me and a buddy and his 06' 636, which is stock but he weighs alot less than i do, anyways my question is that 2 days ago i put a -1 lower front sprocket thinking it would definatley take care of my problem, but now he beats me even worse! The only thing i recived from the sprocket was the ability two do better wheelies, is there something wrong or is just how it is!