1

I have a hybrid bike, which, when I am sat on the bike, shifts and remains into the largest cog on the rear cassette with no problems.

However, if I take my weight off the bike, then when I start pedalling again, the chain skips between the largest and second largest cog until it settles back on the largest cog. Also, it is impossible to get it to shift into the largest cog when the bike is upside down.

I've tried loosening the L screw, but it hasn't worked yet. I'm guessing that if I keep loosening it it will eventually work, but the fact that the adjustment is so dependent on the load on the bike is making me think that something else might be wrong. Is there anything to worry about out or should I just go ahead and keep loosening the L screw?

Improve this question
6
  • If you back off the lower limit screw too far, you'll either overshoot the largest sprocket, or end up with your derailleur cage pinging-on then catching-onto spokes. Wither could be a ride-ending experience.
    – Criggie ♦
    Sep 13, 2016 at 9:08
  • Clarification: When you say its load-dependent, do you mean it gets worse when you stand on the pedals which puts more pressure on the pedals? Have you checked your chain and sprockets for wear? Skipping under load may be a symptom of wear.
    – Criggie ♦
    Sep 13, 2016 at 9:10
  • 1
    @Criggie No, it's other way around. It is fine under load. The issue is when setting off after stopping at lights or setting off for the first time, because the load was temporarily removed, it starts skipping for a bit
    – texasflood
    Sep 13, 2016 at 9:18
  • 1
    As far as I remember it works fine on a climb
    – texasflood
    Sep 13, 2016 at 21:50
  • 1
    It sounds to me like the frame is flexing and that affects the cable adjustment. It's possible that the frame is cracked, or that the cable is somehow misrouted such that frame flex affects it excessively.
    – Daniel R Hicks
    Sep 13, 2016 at 22:15

1 Answer 1

Reset to default
3

Before you go any further, you should check (or have it checked at your LBS) your derailleur hanger. Oftentimes when the RD acts up and won't "tune", it has a poor reference point to start from. The derailleur hanger is easily bent out of alignment,and can render the rear an unreliable little beast. Double-check for any side-play in the crank, to see if that isn't a contributing factor, and get that hanger looked at. Good luck.

Improve this answer
2
  • 1
    Also the derailer hanger mounting hardware.
    – Nathan Knutson
    Sep 13, 2016 at 15:45
  • True. I've seen one actually cross-threaded. God knows how he did it.
    – MikeW
    Sep 15, 2016 at 13:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.