Whenever I shift the rear to a harder gear it bangs into position after about ½ a second pause. This of cause is exaggerated under load and can cause a knee/bar interface.

Is it a case of the cable has streached and they need re indexing or is it more sinsiter. The setup is a X9 shifter and a X5 mech that has seen better days. I know the mech needs replacing for various reasons but dont want to just yet.

Any ideas?

Sounds like sticking/dirty cables rather than stretched.

Sticky cable?

erm… sounds like the spring is buggered in the mech and not dragging it down quickly OR your cables are full of crap/rust and not slipping down the outer quickly…

sounds like something a new set of cables and a good degrease and lubeof the mech will solve

1. does the chain skip when you select a gear? if yes, re-index gears and go from there. if no;

2. change cables. still a problem?

3. how old are is the chain/cassette? if they're pretty worn together, shifting wont be so crisp. not fixed yet?

4. spring in mech is gone.

hope that helps!

Cables are fully sealed and only a couple of months old so I would think they are fine. I dont normally have a problem with sticky cables especially after only a couple of months.

And Ive not had the spring in a mech go before. but it is a crappy mech.

Bent mech hanger? Even slightly out can cause problems.

Take the end caps off the cable sleeves and trim the sticky out bits of wire off. These are what's causing the miss-indexing. Clean it all up and re-assemble with some light grease or oil in it. While it's off check the rear mech is moving freely.
Oh, and as PP says, make sure the mech cage is totally parallel with the sprockets on a middle gear.

Forgot to mention this has only just started happening. The gears worked excellently not long ago and all of a sudden they started doing this.

FWIW It's goodridge outer cut with a Park cable cutter very neatly. The inner is the std Sram one that came with the shifter.

I will have a look at it tomorrow. Keep the ideas coming I will have a good look at it you may have thought of something I hadn't.

could it be that the new cables have stretched (as all cables do over time) and the gears simply need re-indexing.

The gears worked excellently not long ago and all of a sudden they started doing this.

SRAM gears have a habit of doing this. Check the indexing, but it could well be a bent hanger

Most cable stretch is actually the sleeves settling down. Quite often the plastic inners and outers settle down leaving the longitudinal wires exposed. These bend when more cable tension is applied and cause the indexing to go off.

Sounds like dirty cables.

Only a few months but in the UK what a few months!

What you described for my bike its old and poorly maintained

Sounds like you've got to many gears…. get a SS

GS: I have a SS but I fancy at least 9 gears on my 6" FS, Im not a sadist!

ampthill: You are probably right I cant be bothered and don't have the time to keep my bike spotless and overly maintained.

Anywhoo I've just given it a good going over and its a combination of three things.
Firstly the gears were slightly out of index only very slightly as it still shifted just a bit slowly up and too fast down.
Secondly the bolt holding on the mech hanger was loose this ment that the mech could and did move around under load.
Thirdly the pivots in the mech seem a bit worn as it isnt moving smoothly like it should. I guess thats because its a cheap mech tho.

I have fixed the first two but am leaving the mech until it gets worse.