Lost one speed on front shifter

cpper
cpper Posts: 42
edited October 2015 in MTB workshop & tech
Hello
I wondered what this knob:
attachment.php?attachmentid=1023350&stc=1

is good for on my Shimano Deore fd-m610 front shifter and loosened and tightened it today, to see what happens. Afterwards, I realized that I'm now only able to change between 2 speeds, the big chainring and the middle one. When I'm trying to downshift on the small chaining, the shifter does not click. The downshifting-lever moves towards the handler bar, but nothing happens. The red indicator also remains in the same place(middle). I tried to adjust the knob in all ways but could not get it back. The bike is pretty new.
Any thoughts ? :cry:

Comments

  • Mad_Malx
    Mad_Malx Posts: 5,001
    The knob is for fine tuning the shifter cable tension.
    Sounds like your cable is now under tension all the time, so it can't drop down to the smallest ring.

    Assuming the only hing you have done is adjusted this knob, the you need to wind it back in (clockwise viwed from the cable sheath side) until your bottom gear click returns. You may need to wind it a bit further to get the indexining spot on.

    When in the bottom (smallest) front cog, the cable should be un-tensioned (just).
    If it doesn't drop down when wound full in then the shifter may be sticking, assuming you haven't altered the stop screws on the derailleur and it was ok before.
  • cooldad
    cooldad Posts: 32,599
    Read Parktools before you fiddle randomly.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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    Parktools
  • cpper
    cpper Posts: 42
    I figured out what was the problem. I accidentally switched on 2 gear mode(apparently my shifter has this feature I didn't knew of). Mad_Malx, thank you very much for taking your time.
  • Mad_Malx
    Mad_Malx Posts: 5,001
    I figured out what was the problem. I accidentally switched on 2 gear mode(apparently my shifter has this feature I didn't knew of). Mad_Malx, thank you very much for taking your time.

    Didn't know this had a 2 gear mode either, so we both learn.
  • To fit a new cable in these you need to flip them into 3 speed mode to be able to remove and fit the head of the cable.
    It's a little flat bladed screwdriver clicker mounted near the base of the downshift lever in line with the cable entry.
    Very close to the cable tension adjust and easy to see how he accidently bumped it.