XTR M900 rear mech setup issue

[Rev Cannon Dale]

Frank- what shifter are you using? XTR or gripshift?

Cassette shouldnt make any difference unless you've got the wrong lockring on.
On any "open" cable runs, hold the cable taut and see if you go through all the shifts. You should be able to feel the indexing.
I've had some shimano cables where the ferrules have held on tight to the inner wire, and not letting it go.
Have you put the cable under the clamp nut correctly? Often done, and it pulls the cable off centre and at its limit, drawing it across the end of the barrel adjuster.

Gripshift notoriously bad for dropping when shimano went light action, stronger mech springs were available.

I think you'd know if the mech was toast; there'd be that much play, the cage generally skews out at a stupid angle.

 

[perry]

Have you tried giving the pivots a lube ? I have to work on a lot of crappy bikes and a lot of mechs lose movement due to rust or filth stopping them from returning . I've spent a lot of time shouting at mechs " shift down you fooker !" and giving them a good pull back and forth to free them up

When doing the outer cables don't forget to file the end flat . I push the cable through to clear the ends then pour chain lube in to make them smooooth , if you want to you can even put a tiny bit of grease in the little bits you push on ( damn I'm tired and can't think what they are called ) to stop damp getting in .

 

[RockiMtn]

I'll have to give that wheel some play time in my other bikes again. Yes I'm using GripShift X-rays on all three bikes. Right now the Cirrus is working great again with the original rear wheel I had on, so I'll try the wheel in that bike first. The Cirrus is Xray Gripshift with XT M737 rear hub/cassette/mech.

I'm aware about possible issues with GripShift and soft Shimano rear mech springs. Hence I do have an original Sram Bassworm on the Cirrus. Maybe sourcing a few more is in order.

 

[Rev Cannon Dale]

Hi,
Is the bassworm the thing that pulled on the cable, or the replacement mech spring??
I remember fitting 1 or 2 of those little blighters.... :evil:

 

[RockiMtn]

piece of stretchy silicone tubing fitted around the shift cable, attached to the last cable stop and directly to the cable.

 

[FluffyChicken]

This is the old style spring 'peg type' (no idea of real name), before they went to the 'spring' spring in the M910/M737's etc..
So shouldn't be a problem. Assuming your shifter is running sweet (light grease/Vaseline all over and the 'spring' in it is the correct way around and they're not worn.

All that changed apart from the move to IG profile from HG between the cassettes is they riveted the spider ('stiffer') like the M737 as the screw and especialy the 'mini chainring bolts' come loose and before you know it you have no chainring bolts.

Again the larger size larger size cassette is the same other than the spider design to hold the 32 or 28 ring.
I have both on my shelf.

Also the body is changed for the new cassettes:

I believe that is referring to the 'compact 11 tooth' design and so has the smooth part and no outer threading on the freehub body (and so loosing the uniglide compatibility)

So I don't need to read thruogh again.
Does it work fine with this cassette if it on another hub in this bike.
Does another cassette pretty much the same work fine ?

You could try tightening the b tension a touch if you have it set for a 28tooth and you're now putting a 32 on. I may be a little too close.

 

[RockiMtn]

K, took some time and concentrated on the rear mech. took it off the bike and it's definitely sticky at the very end of the return. if i take it and pull the cage all the way and let it go, it will retract all the way with metal to metal "slap" at the end. if however, i take and just tug it just a bit, similar to shifting only 2-3 gears, it will not retract all the way, settling to stop at about 2nd gear, but if i nudge it a little, it will reluctantly slide back to 1st.

This sux since the mech is in immaculate condition showing very little sign of usage and virtually no real wear. there's no looseness in the pivots/joints whatsoever, and this seems to be the problem, it's seems too tight. played with two other more worn and well used XTR M900 rear mechs I have and they are smoother and snappy at the bottom range compared to this one.

Is there any way to service this mech? Can I replace the spring and will it help? the spring seems strong though and might not be the problem. could I soak the mech with degreaser and then re apply grease to the spring and lube the pivots?

 

[S8-Tom]

Try soaking it in a lubricant/light oil. The Finish Line green cap chain lube is very good for this as well as for cables, fork seals... and chains

 

[Rampage]

Is that the washing up liquid one?
It looks, smells and feels like it! Has anyone ever done a taste test?

 

[RockiMtn]

Ugh… soaked the pivots with degreaser, ran it under some hot water, dried and then re-lubed. Darn mech still won't shift down into first. 2nd to 8th perfectly fine though. :roll:

Any other suggestions on what I can do? Is there anyway to swap out the spring? Just doesn't seem to have that little extra snappy "oomph" to push it the last little bit. :?