rear mech will not shift correctly.

markymark113

After damaging my trusty old XT rear mech I decided my replacement would be an upgrade.
I purchashed a shiny new XTR M972
On my first ride I noticed really slow upshifts , generally if I want to go up 1 gear I would have to upshift 2 gears and down shift 1.
Pain in the backside , I assumed I had a cable issue as I only changed the inner not any of the outers.
I then purchased a set of sealed cables , fitted them , 1 hour on the workshop stand and the problem hadn't been cured.
On close inspection I realised thet the rear mech sometimes isnt taking up the slack of the cable .
The mech is clean and well lubed.
Being used with rapidfire shifters.
Has anyone else suffered similar?
Thanks in advance for any answers.

bennett_346

You didn't buy a ten speed mech did you?

cooldad

10 speed is M980 series.

Chunkers1980

Might be the other way, 9 mech and 10 shifter?

List your entire spec inc. part numbers

ilovedirt

Or that he just doesn't know how to index a mech properly.

nicklouse

there is no need to shout.

and most likely new cables needed.

cooldad

nicklouse wrote:

there is no need to shout.

and most likely new cables needed.

Except

markymark113 wrote:

I then purchased a set of sealed cables , fitted them , 1 hour on the workshop stand and the problem hadn't been cured.

cooldad

Mech hanger bent when the mech got broken?

Greer_

Poor cable routing?

YeehaaMcgee

crimped the ends of the cable outer when he cut them, meaning that the inner doesn't move smoothly?

markymark113

I fitted cables very carefully , outers arent crimped or bent.
Gear hanger was replaced at same time as new mech was fitted.
Shifters are LX rapidfire 2006
As there is slack in the final part of cable ie just above the final outer and from outer to rear mech clamp it would point towards the cables doing their job properly.
If you pull the rear mech after gear change is made then it will move thus selecting gear.
Strangely the mech seems completely free moving (as it should being brand new) but really "lazy"
I have emailed chain reaction where I purchased it from to see if they can shed any light.

YeehaaMcgee

markymark113 wrote:

As there is slack in the final part of cable ie just above the final outer and from outer to rear mech clamp it would point towards the cables doing their job properly.

Er, nope. That would suggest to me that there's friction in the last bit of outer, which causes the rear mech to be sluggish.

markymark113

As posted the slack is from the outer to the clamp as well so the Whole section of cable is slack!

benpinnick

Sound like you've put it on wrong. Check that the b tesion screw is behind and engaging the tab

The Rookie

Is the cable slack in almost ever gear, is it still slack in top (smallest) gear?

markymark113

Cable only slack when selected gear hasn't engaged

bails87

Sounds a bit like sticky pivots on the mech. Does the mech move freely when there's no cable. If you push it up to the biggest cog does it naturally drop back down to the smallest one when you turn the pedals?

And all of your kit is the same speed isn't it? 9 speed shifters with a 9 speed mech and cassette?