[brozek]

I have a broken XTR M952 rear derailleur that needs a lower pulley, b-axle assembly, and cable clamp, and I have a new rapid-rise XT M760 that I'm not using and could take all those parts from. My first question is whether or not the parts the XTR rear derailleur needs are compatible with the parts I could pull off the rapid-rise XT derailleur - I can't see how they wouldn't be, but it doesn't hurt to check. The second, and more difficult question, is whether it would be more cost effective to sell the XT derailleur and buy the XTR parts from somewhere like Cambria than cannibalizing it and leaving myself with a partially-disassembled backup. What would you do?

 

[deoreo]

You should be able to use everything from the M760.

If it was me, I'd sell the broken XTR for parts, and sell the new XT, then buy
a new XTR M952.

http://www.supergo.com/profile.cfm?LPROD_ID=8307&srccode=1859&PID=484346

I have pieced together a few derailleurs, and I don't usually trust one once
it has had the mount pivot opened up. Maybe I'm paranoid, but they never seem as
tight as new, and I worry about spinning the b spring (this has happened to me).

So again, if it was me, I'd get a new M952, and maybe a new XT M750 as a back-up
if you ever rip off the XTR.

http://www.jensonusa.com/store/product/RD707A04-Shimano+Xt+M750+Rear+Derailleur.aspx

 

[Hecubus]

You can interchange most of the parts but I wouldn't recommend cannibalizing a new derailleur for it. All thos small replacement parts are sold through QBP catalogue which you can find online or at you LBS.