mdelrossi

Hey all,
I have a Shimano Tiagra 4501 left shifter that does not want to trim the small chainring.
It makes a click but does not move the derailleur. When pushed all the way it shifts but with a very loud clunk.
I flushed it out and relubed it, changed the cable, re adjusted the derailleur.
Same problem.

I have the same group on another bike and it trims and shifts a lot smoother.

Any ideas, or am I in for a new shifter?
Thanks in advance
mdr

Andrew R Stewart 

Cable tension too much? Andy

Retro Grouch 

If it was my bike I'd try the WD-40 flush again. The issue with those is the original grease hardening up. Left shifters aren't likely to get cycled as often rights so the grease is more likely to harden up. Even if it doesn't work, it's worth what it costs to try.

Bike tinker man

I assume the cable routing is outside the frame as its 9 speed ? as you may not be able to see any nicks if its internal, I've in the past when I've had sticky cables is to release the cable from the FD & then clamp a pair of Mole grips as weight on the inner cable end, & index the shifter & ensure its smooth also in this situation you can pull on the Mole grips make sure its free & not binding anywhere, sometimes the inner cable when its worn will just have a little steel bubble like a pin head on the cable & this catches the outer cable.

deegentim

+1 on the cable tightness. I had the same problem with my Tiagra left shifter and loosening the cable to "just tight enough" solved the problem.

mdelrossi

Thanks all.
I did revisit the cable tension and found to that I had missed a cable routing through the frame BB and up to the FD.
I had a devil of a time trying to rout the cable with a bit of fray. However I remember a youtube video where (Art's cycle I think) used a straw or a piece of cable casing to facilitate the routing. I had neither but I did have some 12 gauge electrical cable (Romex) from a recent remodel. After stripping about a 12" piece of insulation off, and using the insulation, it was the perfect inside diameter to help fish the cable through the frame. .

After that, rechecking that I had inserted the cable properly in the shifter, re checked the tension, his and low limit screws, and ran through all of the gears its shifting much better now .
Thanks again to all.
mdr

Andrew R Stewart 

mdr- Thank you for the follow up post with your solution. This is the process loop that we need to learn from. Andy