Rear Mech issue when on hills quickly

saprkzz

So I have a problem with my bike that is doing my head in,

When riding, no matter how fast its fine, when climbing on a back breaker, at a nice constant pace in or out of the saddle its fine... however when I try a flex my pecks and fire up a hill, the rear mech starts "ticking" like its in between gears. This can happen if I change just before I sprint, or even if a remain in the gear I am in.

I have had a play around with the bike on the stand and see no obvious problems, and just can not see what it is.

Just before I go and spend £200 on a new one to try and solve it, can anyone relate to this problem and a way of fixing it?

The rear mech (and groupset) is Sram Red.

Ta in advance

ride_whenever

what frame? Sometimes happens if the cable ends aren't ferruled and then the outer frays. causing the shifting to wander under load.

Essex Rouleur

Sounds to me more like an alignment problem and should be easily solved by re-tuning the rear derailleur. You might not think this is the case due to the fact the gear shifts fine every other time, but when you align the rear derailleur on a workstand there is no load on the wheel, chain or cassette. The minute you get on the bike and push it, which seems to be the case for you, then the alignment can easily be out of true. Thats when you get the clicking noise, especially when pushing the bike hard.

Its quite a common problem, the alignment just needs tweaking a tiny bit, but its not always easy to guess which way when its so small.

Try it a small amount one way, ride out, push it and see if it makes the same noise. It may well be that you cant change it and just have to live with it, as the tolerances are so small with modern cassettes and chains.

Monty Dog

Also check that the rear mech hanger is secured properly i.e. the screws haven't come loose.

saprkzz

Excellent advice all, thanks I will check screws & bolts first, then tweak alignment and have a ride out.