The rear derailleur on my Huffy 21 speed bicycle does not switch anymore. It will click and turn, but the gear won't switch. When I attempt to force it manually it switches back to the biggest gear (smallest cog?). Please help, it's my only mode of transportation.

  • 2
    It could be a minor cable adjustment, it could be a major overhaul of the shifters and derailers. Start by reviewing this video: parktool.com/blog/repair-help/how-a-rear-derailleur-works – Daniel R Hicks Jan 25 '18 at 3:30
  • 1
    There may be several issues with rear gears; you'll have to provide pictures of the rear derailleur (different views will help) before anyone could help you. However, just from the fact that it slides to the smallest (?) cog I would make a wild guess it is a broken cable. – Grigory Rechistov Jan 25 '18 at 7:19
  • 1
    How old are the cables? They may be rusted or stuck inside the housings. Best idea would be to replace cables and housings. While you're at it, maybe also for the brakes. It's a good thing to do after two or three years of use as a safety measure anyway. – Carel Jan 25 '18 at 8:39
  • Isolate whether its the shifter, the cabling, or the derailleur. Hang the bike up, and while slowly pedalling use your hand to pull the exposed taut inner wire. If that's still bad, then carefully push the derailleur with your left hand. Mind fingers! – Criggie Jan 25 '18 at 9:12

If the shifter does not move the derailleur at all, then either:

  • A cable housing has come free from the shifter unit, frame boss or derailleur
  • A cable end has detached from the shifter
  • A cable end has detached from the derailleur
  • The cable has broken (least likely)

Basic things you can do to find the problem:

  • Find an exposed bit of cable (the inner silver cable, not the black housing) on the frame somewhere. It should be taught and not loose.

  • Inspect the shifter cable run from the shifter to the derailleur, make sure the cable housing is inserted into the shifter unit, all frame bosses and the derailleur.

  • Find an exposed bit of cable near the derailleur, grab hold if it (using pliers will help), put a little tension on it and operate the shifter. If the cable moves it's attached to the shifter.

If the cable is moving near the derailleur when the shifter is operated, check the cable is attached to the derailleur.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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