M950 XTR advice

[Barberossa79]

Iirc Xtr octalink isn't the same as the cheaper mtb units.

If you mismatch the splines you'll ruin the chainset. It's been done many times, making an xtr m950 chainset a risky buy.

Symptoms? Creaking and falling off, like square taper

Interesting, initially I had a bit of trouble with alignment but got there in the end. Not been ridden in anger yet though. Will keep an eye on it.

 

[Barberossa79]

Only V1 105 is a substitute but it’s the wrong lengths.

If folk insist on using a XTR chainset then they can’t complain about £40-50 for a BB to fit it in my opinion.

All the others have different splines which damage the cranks splines

To be clear i have 950 chainset and bb so it's matched up.

 

[ishaw]

Only V1 105 is a substitute but it’s the wrong lengths.

If folk insist on using a XTR chainset then they can’t complain about £40-50 for a BB to fit it in my opinion.

All the others have different splines which damage the cranks splines

Not strictly true. Any v1 splined BB is compatible, 105 is the lowest rent option. Ultegra and Dura ace work too. Still the same challenge with axle length, just more expensive.

 

[bikeworkshop]

I'd have a very close look before assembly, and also snug it down after a test ride, the splines in the chainset are easily damaged by careless fitters and incorrect bb splines.

Xtr octalink bbs are £££ for a reason, rarity.

 

[d8mok]

Not strictly true. Any v1 splined BB is compatible, 105 is the lowest rent option. Ultegra and Dura ace work too. Still the same challenge with axle length, just more expensive.

Maybe I should have worded it better. Only 105 is a cheaper substitute.

As Dura and Ultega is the same price as a XTR and then the wrong size still so nobody would do that.

 

[pwebb]

Maybe I should have worded it better. Only 105 is a cheaper substitute.

As Dura and Ultega is the same price as a XTR and then the wrong size still so nobody would do that.

Dura Ace an even bigger can of worms than XTR so agree that wouldn't be a substitute, however there is a lot of NOS V1 octalink out there and prices can be random. It's a good callout that BB lengths may be wrong, however that may well help with a BB shell and chain line that was never intended to be used with XTR as it predates it. I know this is somewhat theoretical, but as NOS parts get ever more scarce, mixing and matching becomes a necessity. I tend to adopt the ethos of Sheldon Brown who showed that a lot of seemingly disparate parts can be made to work harmoniously provided you get to grips with what works with what and why. This thread is a great resource so bookmarked by me as I am so forgetful these days.

 

[Barberossa79]

So problem solved. Only the 952 is bottom pull so that will be the one that's going on clamp size is wrong so it'll need a shim.