I just bought a second-hand bike and am trying to adjust it but quite new to bike mechanics.
on the left I have a thumb-shifter with 3 settings.
to move it into 3rd gear takes a monumental thumb-push which still has my thumb aching hours later.
I tried the barrel adjusters but any movement either way seems mess up the shifting.
When I watch the gear shifting I see that the front derailleur moves into the correct position when the thumb-shifter has travelled halfway through its journey. The rest of the movement to the point where the the thumb-shifter locks does not move the derailleur at all and is just hard effort on my thumb.
Any help greatly appreciated.