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I have recently bought a new road bike. On my first ride out, when shifting the the front derailleur onto the big ring the cage would shift over but the chain would not. I took it home and adjusted the height and angle of the cage and tried to remove slack from the cable, I did not touch the limit screws. However this seems to have made the problem worse as I when I shift the front gears the cage doesn't even shift at all.

Not sure if this will help but here are some photos : https://imgur.com/a/1oVjDLX

I've tried looking for answers online and the suggestion is not enough tension in the cables. When I shift onto a higher gear there is little to no slack in the cable but when I shift down there is a lot of slack again after tightening it up, is this normal and could it be the cause?

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    Generally speaking a new bike from a bike shop comes with a free tuneup at 4-6 weeks. This allows time for cables to settle, and gives the shop a second chance to sell you more accessories. – Criggie Aug 25 '18 at 8:36
  • Check bicycles.stackexchange.com/questions/13424/… for possible duplicate. – Criggie Aug 25 '18 at 8:39
  • @Criggie thank you, I will have a look. Unfortunately I purchased the bike from Decathlon (chain store) and the nearest one is quite far. I will probably take it to a LBS and ask for help if I cannot get it fixed. – Will Aug 25 '18 at 8:49
  • In general, if you make the cable slack, you should be able to move the derailer by hand. (It takes a modest amount of force to move it against the spring.) So the first check would be to see if the derailer is moving freely all the way over. Note that a modest amount of "overshift" is required to achieve a shift to a larger ring, particularly when shifting to the top ring, so it may be that the top limit needs tweaking. – Daniel R Hicks Aug 25 '18 at 11:29
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As others have said front derailleurs are a pain to adjust correctly, so taking you bike to a local repair shop will save you headaches.

However, if you want a shot at getting the front derailleur adjusted properly yourself, stepping through a full adjustment procedure is the way to go.

Park Tool has a great webpage and video that walks you through the entire process.

https://www.parktool.com/blog/repair-help/front-derailleur-adjustment

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The last paragraph sounds like the cause. The cable should be always tight so that it can actually pull the derailleur. Try first downshifting the shifter, then pull the cable tight. The first paragraph sounds like you may also have to adjust upper limit screw.

  • So I downshifted onto the lower gear and pulled the slack out. However when I shift back up and then down again the cable becomes loose once more. Wonder why that is happening? – Will Aug 25 '18 at 8:16
  • @will if you hang the bike so the rear tyre is off the ground (use rope or cord) and then slowly pedal with one hand, then pull the exposed visible inner cable with the other, does it shift? Part 2) just the same, but use one hand to directly move the front derailleur cage while pedalling slowly with the other hand. Does it shift? The FD is a fiddly wee thing where every adjustment affects other things in turn. – Criggie Aug 25 '18 at 8:38
  • @Criggie No to both scenarios, when moving the cage by hand the chain also stays put. Do you think I should leave the limit screws alone or should I try and adjust those? Right now I have only played around with the height, angle and cable tension. – Will Aug 25 '18 at 8:46
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    If the cable slips when you upshift, either the bolt is extremely loose or the upper limit screw is much too tight and the cable slips when you are pushing against the limit. Adjust the limit screw. Or take the bike back to shop, it is set up poorly and the shop should be able to do better. – ojs Aug 25 '18 at 10:47

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