I had an issue with my from derailleur and took it into a bike shop where the guy told me nothing was wrong with it even though I was noticing some noise coming from it. I then tried velofix the bike service and they fixed it. I rode 50 miles outside and then put it on my trainer where it was working for a while. The next ride after that though the big gear up front stopped shifting down to the small gear as shown in this video:


My question now is do I attempt to take it to another shop? Take it off the trainer to see if I can get it to shift with my normal wheel? Should I mess with the limiting screws to fix this? What would you do? I can use it on my trainer in ERG mode without shifting gears, but that's not a long term solution. I am also wondering if it's my chain that could need replacing...

I am not an experienced bike mechanic, thanks.

Thanks, Evan

  • Check if the derailleur moves a little bit or not and all, and whether the exposed section of cable is loose (so it buckles out) when you shift. Jan 25, 2022 at 14:49

1 Answer 1


There are a few things that could be at issue:

  • Lower limit screw might need to be opened up. You could try opening it all the way up, and then experiment with tightening it just to the point where you have shifting problems, then back it out slightly. Of course, that won't help if it's not the cause.
  • Crud in the cable housing might be preventing the cable from fully "relaxing". You could try shooting some WD40 into the housing as a first step.
  • Derailleur position could be slightly misadjusted in height or rotation on the seat tube. Harder to diagnose. I found on one of my bikes that I needed to rotate the derailleur so that the rear of the cage pointed slightly toward the centerline of the bike to get good downshifts.

I doubt that it's the chain, although it's easy to measure chain elongation.

I very much doubt this your problem, but I've got a bike that lives full-time on my stationary trainer, and sweat has caused the front derailleur to completely seize up.

  • Yes, probably the lower limit screw. Could also be too much cable tension or friction in the cables. Maybe the cable is breaking/fraying inside the shifter, which could explain why it’s getting worse. Or the derailleur isn’t clamped to the frame with sufficient force which makes it twist ever so slightly over time. This would also explain why it’s getting worse.
    – Michael
    Jan 25, 2022 at 18:28
  • I found out that the front cage that moves the chain over is completely broken at the top. It must have broke while I was riding it, but the top of the cage is definitely broken so the cage no longer has integrity. I am going to take it to a store and see if they can swap it out.
    – Ebay89
    Jan 26, 2022 at 5:18
  • Hah! Well, that would do it.
    – Adam Rice
    Jan 26, 2022 at 14:03

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