Left Tiagra 4600 shifter goosed??

Discussion in 'Bicycle Mechanics and Repairs' started by pfm401, 16 May 2018.

  1. pfm401

    pfm401 Regular

    All

    I'd appreciate a bit of advice here! On a ride this evening the left shifter (Tiagra 4600 triple) stopped "clicking" into indexed positions. It's on the smallest chain ring; if you push right and hold whilst pedalling it moves to the middle chain ring but no "click"; if you let go it shifts back down to the smallest chain ring. I can't push it further than the middle chain ring. To check it's not the cable, I undid the cable, and no "click" without the cable attached.

    Goosed or simple fix? I had a quick look for replacements and they're not exactly cheap!!!!

    Any advice appreciated!!

    Thanks, Paul.
     
  2. themosquitoking

    themosquitoking Veteran

    Location:
    Spain
    Check the cable isn't fraying inside the shifter or anywhere else.
     
    raleighnut likes this.
  3. raleighnut

    raleighnut Guru

    Location:
    On 3 Wheels
    A good squirt of oil might free off the detents as long as you've eliminated the frayed cable.
     
  4. OP
    OP
    pfm401

    pfm401 Regular

    Cheers guys! The cable is quite new; I've checked it and no fraying ends. I sprayed GT85 in there very liberally which has helped; it sticks in the shifted position now but still no "click". I reconnected the cable and it shifts horribly; no "click" shifting from small to middle or middle to top (at least it engages!!) and clunky at best dropping back down. At worst it drops from top to bottom position with one click down (on the shifter as well as the derailleur).

    Part of the above is obviously because I haven't adjusted the cable when I refitted it but surely it shouldn't move from largest to smallest chainring (it's a triple) in one click down??

    Rightly or wrongly I'm giving up and going to the LBS! Thanks for your help.

    Paul.
     
  5. ianrauk

    ianrauk Tattooed Beat Messiah

    Location:
    Barmy in Barming
    What ever the Shimano shifter, it always seem to be the left one that goes. I have had both 105 and Ultegra left shifters go.
     
    Eddy likes this.
  6. OP
    OP
    pfm401

    pfm401 Regular

    It's done 11,000 miles and is 3.5 years old if that helps - no idea if that's good or not!
     
  7. Ajax Bay

    Ajax Bay Veteran

    Location:
    East Devon
    I'd say 11,000 miles was pretty good. Probably less than the MTBF but nonetheless. If it can be fixed a decent LBS will know how. Otherwise, any triple STI should be effective, but cosmetically/aesthetically I guess you'd want to find one to match your RH STI.
    Just to add, the cable tension and changing force (changing up) on the LH STI is greater (than on the RD/right hand STI) because of the poorer leverage angles of the FD's clamp arm (behind the seat tube, down pull) and the 'clunk' when one drops to a smaller chainring (further than the lateral distance between adjacent sprockets). Think about a plot of the cable tension against time when such a change is made. And then extrapolate that a thousand-fold for 1000s of miles of changes and the step changes in cable tension at the detents in the STI.
     
    raleighnut likes this.
  8. si_c

    si_c Über Member

    Location:
    Wirral
    Sounds to me like a new left shifter.
     
  9. alecstilleyedye

    alecstilleyedye nothing in moderation Staff Member

    you’d think it would be the other way round, although perhaps moving from small ring to big puts greater strain on the shifter...
     
  10. Ajax Bay

    Ajax Bay Veteran

    Location:
    East Devon
    Did you read my post?
     
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