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I have a used 2011 trek 1.2 compact road bike with a stiff Sora FD-3400 double front derailleur.

Shifter seems very stiff, and when I shift above the second index (trim or third) by accident it gets stuck on the big chainset ring and then it takes a huge amount of force to release it or even impossible and I have to release the shifter cable from the derailleur. As I understand I should set the top limit so it won't go over the second index right? But even if I shift to the second index and try to lower to the first it takes some heavy force and there is a loud clank when it does get released.

I think its the derailleur because when I detached the derailleur, pulling the cable in the housing seems smooth, and the shifter has good and smooth pull and release for all its indexes and trims.

Here's a video of me pulling hard on the cable

Here's my video of how hard it is to move:

Compared to what I see here at 1:34 mark:

when it does shift this is the sound it does at the end of this video (not my video)

I also suspect the previous owner had something to do with it, since there is a little dent under where the derailleur clips shown here:

Am I right thinking its the derailleur and should replace it? What else can it be that I should check?

  • well, the possibilities are the derailleur, the cable or the shifter - there's not a whole lot going on here. If you've already tested that the shifter is able to pull the cable smoothly, then I agree it sounds like it is the derailleur. Definitely worth taking it apart and (believe it or not) it is possible to attach the cable incorrectly to the derailleur (although its pretty obvious). – PeteH Sep 2 '14 at 13:09
  • thanks, I followed several guides to adjust it, and I think the cable was connected to right place (above that little marking/stop under the bolt, from the clip on side) and tried giving it even more leverage. – Paul Blakey Sep 2 '14 at 13:27
  • Looking at your your second vid (moving derailleur) I must say it doesn't look particularly abnormal to me. Are you sure there's even something wrong with it? – PeteH Sep 2 '14 at 20:19
  • I'm not sure because its hard to find how strong is suppose to be. I do know other models use different width springs. It might be that this model has a tougher spring in combination with the old housing. I know my Specialized Sirrius front derailleur (FD-M191) takes half the force to move it with my thumb. My local bike stores are pretty expensive around here, so I just ordered shifter cables/housing and a new FD-3500 derailleur which might have a lighter spring. for 22$ + 16$. If it is the cable, I just wasted 16$, no biggy. I just hope the shifter is ok which is the most expensive. – Paul Blakey Sep 3 '14 at 12:39
  • Yeah. You have to bear in mind that Sora is at the lower end of the Shimano range, too. (But I've never tried it so can't really comment.) But there might be an element of engineering it to encourage you to get a better piece of kit. New cables are always a pretty good investment though, they're one of these things that degrade without you really noticing, you fit a new set and think "wow". – PeteH Sep 3 '14 at 12:58
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My SORA front derailleur cable broke (after gear change difficulties for several tens of kilometres, and ineffective cable length adjustments). I replaced the cable, but I still had to push the gear change lever very hard to change chain wheels (which is when I found this web page). The culprit was the plastic cable guide screwed onto the frame under the crank (GIANT Cross City 3). This guide had been cut through by the front derailleur cable and the cable had started cutting into the frame. After replacing this plastic guide ($3.00), as well as the cable, changing the chain wheel is almost as easy as when brand new.

  • +1 any time I have had stiff front shifting it has been that guide. – Rider_X Sep 28 '15 at 15:11

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