09-15-2012, 07:03 PM
Never rebuilt a bike transmission but I have done a few GM ones and Volkswagen before. I doubt you can reuse the shift forks on different speed gears because there most certainly different lengths. Im gonna say based on experiance its probably your syncronizers. Theres a brass blocker ring that constantly rides the taper of the speed gear and its the most likely part to wear in any constant mesh. When it wears slippage could result. Your absolutely sure its not your clutch slipping?