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Problem with front derailleur shifting too far

evil73evil73 Posts: 4
edited July 2017 in Workshop
Hello :)
I recently bought a Triban 540 from B'twin with a full Shimano 105 groupset. After a few rides I noticed that my front derailleur behaves a bit strange. When I shift to the big ring everything works fine but I am able to shift up one more time so that the derailleur shifts just a little further up. It's like shifting to an even bigger ring but with a smaller click at the lever and smaller movement of the mech. It's the same thing with shifting to a smaller ring at the front.
As this is my first ever road bike with a Shimano 105 group and my second road bike ever I'm not sure if that's normal. I don't think so. So my question is how to fix this issue if there is one. Occurs this because of stretched cables or do I need to readjust my gearing.
I'm sorry for the quite long text but as English isn't my first language I didn't know how to explain my problem in a quicker way. I also couldn't find an entry where my issue is discussed.
I hope for some advise and that I didn't do anything wrong with my first post.
Thanks Jakob

Posts

  • bianchi_davebianchi_dave Posts: 465
    I think you're describing the trim function, which is perfectly normal. There are 4 front derailleur positions ( 2 for small ring and 2 for big ring (if running a double crankset)). Have a look at this video for set up -

    http://www.artscyclery.com/learningcent ... leurs.html
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  • evil73evil73 Posts: 4
    Thanks for your quick help. I didn't know that there are 4 front derailleur positions but that seems exactly like what I'm facing with my bike.
    Now my question is how to use this "thing". It's it here so the chain won't rub against the front mech when I'm in the smallest front and biggest rear ring?
  • pilot_petepilot_pete Posts: 2,120
    evil73 wrote:
    Now my question is how to use this "thing". It's it here so the chain won't rub against the front mech when I'm in the smallest front and biggest rear ring?
    err, no, that is bottom gear. A correctly adjusted front derailleur should not rub in that combination.

    It is more to do with being in the big front ring and then moving across the cassette. The chain line changes significantly as you move across the cassette and the front derailleur trim is to allow for this variation which would otherwise mean the chain would rub when in more of the rear cogs than does when using the trim function.

    PP
  • evil73evil73 Posts: 4
    Thank you guys so much for your help. I think I got it now ^^
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