>>1163909>>11638502/2
FIRST: check your high limit screw if you havent yet.
https://www.sheldonbrown.com/derailer-adjustment.htmlhttps://www.sheldonbrown.com/front-derailers.htmland you can search youtube for vids
otherwise, it sounds possible that your cable might be frozen in the housing. before you do anything else, squirt penetrating oil into the ends of the housing and work the shifter back and forth to get the cable to spread the oil deeper into the housing. if there is some progress made, repeat the process until the friction is eliminated. last-ditch, upend the bike so the housing is perpendicular to the ground and squirt penetrating oil into the housing and let soak for some hours before working the shifter.
The shifter itself might be frozen, or the pivots on the derailleur, but that's rarer. squirt them just in case.
Not sure what you mean by
>the dails wont let me add or remove any length whatsoverer do you mean the barrel adjuster? it can bottom out one way, but not both ways. if you can't tighten it any further, then you can absolutely slacken it and vice versa--the cable itself doesn't change length except at the bolt.
>am i right in thinking ive ran out of cable length?well, did you? the cable is bolted to your derailleur and the extra hangs off the other end of the bolt. pic related. you can add or remove tension here from the bolt (grip the cable first with pliers, i like visegrips) BUT
before you do, you NEED to make sure your high limit screw is allowing the movement to the the big ring and then that the cable is free in the housing and that the mechs move freely. if you lengthen the cable but it can't move, it's not going to help anything.
