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I am trying to fix the front shifting on a bike (not my own, family member). The original reported problems were inability to shift into 3 (largest), combined with a tendency for the chain to come off when going into 1 (smallest). Essentially, it was stuck in range 2, and I discovered it also would not go from 1 to 2 (after manually putting chain on 1).

I believed the problem would just be a case of adjusting the limit screws, which is something I've fixed in the past. However, this did not improve the shifting - while the derailleur appeared to be in position, the chain would still skip against 2 when going from 1 to 2.

I proceeded to read around a bit and then started to adjust the cable (it's a bottom design, at least I think that's the right terminology) to increase the tension, but still it would not shift properly.

Along the way I've tried various combinations of cable tension (at barrel and at nut) and limit screw adjustments, and still not had a positive impact. Really I should have probably sought help earlier on - I'm out of experience and I can't think of a way forward now. I think I've made it worse so far by adjusting the cable.

The symptoms right now

  • The front shifter allows me to keep rotating it beyond "1" (i.e. off the scale), I'm not sure if this was happening before I started fixing the bike, or if I caused it, or if it's even a problem.
  • When I move the deraileur manually, without the cable attached, it does appear to align properly such that getting both 1 and 3 should be possible
  • The gap between the outer derailleur and chain when in 1 (smallest sprocket) seems to be acceptable and aligned with pictures I've seen
  • I try to attach the cable again using pliers to keep it taut; after doing this, the shifter is sometimes so stiff I can hardly turn it; other times, it essentially works, but only from 1 to 2 (will not move beyond 2). In this instance, the derailleur moves, but not enough for the chain to actually jump onto 2.

Unfortunately I think I've got myself into a position where I've deviated so far from the original problem that it's hard to tell what's going to improve the situation and what will make it worse.

At present, the front shifter doesn't work at all. With the cable attached, and reasonably taut when in 1, I can move the shifter between "0" (as mentioned, the shifter seems to rotate off the scale...) and "1", and observe the cable moving at the derailleur, and some derailleur movement. However, I can't move the shifter past "1", and in any case, nothing I'm trying is actually moving the derailleur sufficiently to change the gear.

Where do I even start? I don't feel like this should be a complicated problem to solve, but I could really do with an "explain like I'm five" overview of things to try to 1) reset all the components so they work individually and 2) work together so front shifting works properly and is fully indexed.

I don't know enough about bikes to say what shifter it is except it's Shimano and has GripShift Max twist shifters on the handlebars, and they are indexed 1-2-3 with three distinct clicks (as opposed to my own bike which is labelled L-H and has no distinct clicks).

  • Sounds like the cable is rusted and sticking. – Daniel R Hicks Jun 24 '18 at 18:06
  • If its a grip shifter I'd bin it straight off and fit either a triple position trigger shifter, or an old-school friction shifter. Gripshifts are garbage/rubbish. – Criggie Jul 25 '18 at 7:06
  • Agreed, reading through everything, either the cable is done or the shifter has failed somewhere, it shouldn’t move to 0 position. Either case is not that simple to fix your first time. Installing the cable in a friction shifter however is super easy – Swifty Jul 25 '18 at 8:15
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Best approach is to start from scratch following a procedure so you know you are not making things worse.

There are a few youtube videos that walk you through the procedure. My favorite is Park Tool Company’s as it’s the easiest to follow and includes checking height and yaw. (Link at bottom.)

Before attempting the adjustment, make sure the cable and housing is properly inserted into the shifter body and and the guides on the frame.

Another thing to do is check the shifter is pulling the cable properly, and the cable is running freely independent of the derailleur. Disconnect the cable from the derailleur, grab the cable and put some tension on it (a set of pliers can be helpful), then turn the front shifter through it's clicks. You should feel the cable retracted and released.

Front derailleur and shifting adjustment is pretty tricky, so don’t feel bad that this has got the better of you.

  • The fact that the cable runs freely through the housing when disconnected from the derailer is no proof that it's OK. Had one last week where the front refused to shift more than halfway. The cable seemed to work OK loose, but there was too much friction when under tension from the derailer. Took the cable out of the housing and, sure enough, there was rust on the cable where it ran under the bottom bracket. Cleaned the cable with Barkeeper's Friend, sprayed inside the housing with oxalic acid, then gave everything a good bath of Tri-Flow. Worked great after that. – Daniel R Hicks Jun 25 '18 at 2:11
  • True, but its a reasonable check to do, It'll show if the shifter is jammed up or broken, or if there is something badly wrong with the cable run. – Argenti Apparatus Jun 25 '18 at 2:15
  • The video is useful, at least I have a procedure now, although it does feel like I almost need to follow it in reverse, since I can't currently use the shifter at all. Is it a problem that I can rotate the shifter beyond "1" (but not to 2/3, when the cable is attached), or will this resolve once the cable is properly adjusted? – Ilmiont Jun 25 '18 at 15:25
  • @Ilmiont Yes, it's a problem. You definitely want to detach the cable from the derailleur and test the shifter motion and cable pull. The shifter may be jammed, the cable end in the shifter may be hung up or the cable might be snagged somewhere along the run to the derailleur. – Argenti Apparatus Jun 25 '18 at 15:41
  • I think I've broken the shifter, although I'm not sure exactly what happened. With the shifter detached the motion is alright and it pulls the cable, but index 1 doesn't really click and motion continues below 1 as I described. Seems to be the same issue as bikeforums.net/bicycle-mechanics/… I'm not quite what I did but it seems I've broken the shifter so further repair attempts probably aren't viable at this stage; I think I'll just have to offer to foot the bill for a new shifter and professional repair to cover what I broke, disappointing result! – Ilmiont Jun 25 '18 at 21:35

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