Originally Posted by nismosr
Can someone help me adjust my rear Derrailleur - I recently replaced my RD and whenever i'm on the the Big ring and trying to shift it to the smallest cog it won't stay in there and keep jumping to the second cog. I know there's 2 screws in the rear and the knob. which of the 3 I need to adjust in order to solve this problem ? Thank You
The short answer is that you need to adjust your "H" limit screw. The best way to do this is to turn the screw at the same time as you are cranking the pedals. Once you get the chain on the small cog you turn the "H" screw until the chain is not chattering and running quiet. Obviously, you need some type of repair stand to do this. The long answer can be found here:
Another way to get the "H" adjustment in the ballpark (before you fine tune out the chattering) is to observe the position of the jockey wheels with relation to the small cog. Do this from behind the bike looking forward. Just crank that "H" screw until the jockey wheels and small cog are in a nice vertical straight line. If you do that, you're normally pretty close to the final adjustment.
Please note, as stated in the Park proceedure, that your "H" limit adjustment should be done with no tension on the shift cable. Either disconnect it (the best way) or crank the barrel adjuster until it goes slack.
Last edited by cascade168; 11-20-07 at 11:20 AM.