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Thursday, July 14, 2011

How To Fix Your Derailleurs

Please help me I'm so stressed over this. I just bought a new Supercycle bike from Canadian Tire. They did not adjust the derailleurs at the store so I decided to try it but I wound up loosen the cable too much and it came out of the derailleur all together. I am planning a cycling trip to Toronto on the weekend and I don't want to rent a BIXI bike for the entire weekend because that would cost a small fortune. Is there anyway I can fix this myself in a hurry? PLEASE HELP ME. - Andrew in Whitby, Ontario

Not to worry Andrew, help is available but it won't be easy. Derailleurs are basically the most complicated things to fix on a modern bicycle.

#1. First check to see if you have a bent derailleur tab. (You probably don't because your bike is brand new, but lets follow procedure here in case other people have problems.) If it is please see this other post on "Fixing a Bent Derailleur Tab".

#2. Get yourself a copy of Barnett's Manual (the books aren't cheap so a PDF will suffice) and read chapters 33 and 34.

I cannot possibly fully explain all the intricacies of fixing derailleurs in one blog post. Barnett takes TWO chapters to do it, one for front derailleurs and another for rear derailleurs. If you view the PDF it is pages 591 to 649.

Failing that check out this website: which is reasonably helpful, but has really shoddy graphics and skips over a lot of parts (It should be sufficient to help fix Andrew's problem however). That site does however get the point across that derailleurs are basically the most complicated things to fix on a modern bicycle.

Maybe someday I will do a detailed post on how to fix derailleurs, but if I am anything like Barnett such a post would take me a week to write and be 50+ pages long.

Good luck Andrew!


  1. If a caliper brake pad sticks when it contacts the rim, how do you fix that?

    1. What do you mean by sticks and where exactly? There is 2 different possibilities that I can think of for why that might be happening.

      The most likely cause is the spring isn't popping the calipers back out into place and you need to tighten the screw which adjusts the spring. You may need to adjust both screws on each side so it evens out and the calipers bounce back nicely when the brakes aren't being used.

  2. I have an Apollo Altitude 21 speed bike, recently I went riding on some trails and a stick got stuck in the derailer. When I removed the stick, I was able to use the high gears no problem, but the moment I went to go down the gears, my chain becomes really loose and my derailer doesnt want to move.

    Do you have any tips on how to fix this problem please?


    1. Hello Josh!

      Without seeing it I cannot be certain, but my guess would be that your derailleur has become bent and is out of alignment. My recommendation would be to take it to a local bicycle mechanic who is experienced (no rookies on this job) and ask them to fix the derailleur.

      If they can fix it right in front of you that would be great because then you could watch and see what they do, but most bike shops have a backlog of bikes to fix and you might have to wait a couple days to get your bicycle back.



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