Rear derailer slipping when going over bumps?

[Matthew_T]

Something new has been happening. Whenever I go over a very large bump or pothole (I try to avoid them) my rear derailer jumps into the gear above, making things difficult if I am going uphill.

The plate between my bike and the derailer is bent but it has been like that since I got the bike (cannot find a replacement) and I have had no problems with it.

I cannot for the life of me think of what could be causing this jump. Can anyone shed some light?

 

[Manonabike]

I recently had a similar problem and it was driving me crazy. I eventually found out that I needed to re-adjust the high gear limit screw. The problem was happening when I was on any of the 3 smallest sprockets.

The things I checked before I found the solution.... chain too long, chain too short, gear adjustment too tight (adjuster undone too far) I eventually re-adjuster the limit screw and the problem went away.

 

[Matthew_T]

I recently had a similar problem and it was driving me crazy. I eventually found out that I needed to re-adjust the high gear limit screw. The problem was happening when I was on any of the 3 smallest sprockets.

The things I checked before I found the solution.... chain too long, chain too short, gear adjustment too tight (adjuster undone too far) I eventually re-adjuster the limit screw and the problem went away.

I might try that. Thanks.

 

[amaferanga]

The limit screw should only affect the largest and smallest sprockets, unless they're so far out that you can't even use the largest and/or smallest sprocket. Sounds like you need a new derailleur hanger - these are available. Take your bike to a good LBS and they'll help you. That may or may not be the issue. It might be that your gears are just poorly adjusted.