What is the difference between the 7 or 8 speed rear der guide pulley and the 9 speed rear der guide pulley? One difference is the 7 or 8 speed guide pulley is 10 tooth and the 9 speed is 11 tooth. Are they interchangeable?
Edit: Sorry... Shimano Ultegra rear der. I want to put 9 speed pulleys on 7 speed der.