On a ride today, on a gear change, the chain dropped on the front crank. After putting it back on, the rear shifter no longer shifts up or down. The rear derailleur is on the second smallest cog.
- Pulling the cable tube where it leaves the frame at the rear derailleur creates tension in the cable and cause it to shift just fine; when I let go it shifts back to second smallest cog
- The shifting buttons still move, they just don't seem to do anything
- On inspection with the hood peeled back a little, the cable does not appear to move when the either shifter is pressed.
- The shifters feel lighter than usual
- Both the up and down buttons make a soft click and move in the normal range of motion;
- After pressing the shifter a few times up and down at home, a small piece of plastic fell out. It appears to have a scratch/mark on it. It is pictured below. I don't know if anything else fell out at the time on the road
It is a 2020 Giant TCR Advanced Pro Team Disc bike which I bought second hand. I am in Australia.
Any ideas? Is my shifter gone and in need of replacing? Is it likely to be under warranty? Will they honour any warranty if I am the second owner and have no receipt?
[first question here - let me know if more info is needed and I can edit]
Edit: I've taken off the bottom panel (which was loose i.e. the screw wasn't at all tight and the cover was flapping a little) and this is what I see inside. It looks like the cable has fallen out of the stay/holder so the levers aren't pulling the cable.
Applying a little pressure on the where I think the cable should hook in, the up and down shift buttons seem to click normally and the pawl moves up and down.
Could it be as simple as just reseating the cable? How would I get slack into the cable to feed it back up? And what to do with the bit that fell off?
[This diagram helped me. The bit that fell out looks very much like piece number 2: https://dassets.shimano.com/content/dam/global/cg1SHICCycling/final/ev/ev/EV-ST-R8020-4245D.pdf]
EDIT again: I made slack by undoing the cable at the rear derailleur, pulled the cable back through with some pliers and reseated it, then reconnected the rear derailleur and now it shifts normally! Just wondering about that bit that fell out....
EDIT - hopefully final - found the spot for the missing piece - it's the bumper for the shifter button. Pic with the cable seated and the piece reinserted. Just had a little spin on the trainer and it works perfectly and in fact shifts a little tighter since I had to recalibrate the rear derailleur after reconnecting!