Mountain Biking - Old M952 XTR, or new M772 XT rear derailleur- which one to use?

I'm throwing together a new bike for all-mountain use, and was intending to use one of my good ol' M952 XTR rear derailleurs, when I remembered I have a new M772 XT rear-d in my parts bin.

-The XTR is lighter, but the XT has a few improvements in design with the cable pull relocated and the second pivot point, plus longer hinge pins which may make it more rigid.

-The XT is longer than I could ever imagine needing for a 11-34T against a 22-32 double, and the aluminum cage seems like a soft alloy to me. Both are long cage models, with the XT being 25mm longer in the cage than the old XTR. Oddly, the uber-length XT is marked for Mega-9, but should fit a 36T tenner just fine if I decide to later...

I'll be running 9-speed on a M960 cassette and M952 shifter pods. Any thoughts on which would be the most suitable given the choice?

-The XTR is lighter...

The lightest non-tuned 952 actual weight is about 210g.
The lightest 772 actual weight is 223g.

If you're concerned about that ghey roadie weight difference, go pick a pre-ride booger and have a good ride.

. . . go pick a pre-ride booger . . . .:lol:

It may be the paranoid DHer in me but I'd make the choice based on length and go with the shorter one.

I can cut even more by picking both nostrils, and clearing the bellybutton lint as well.

But seriously. I have been riding the M952s for years, that's why I have spares. I have not built a new drivetrain since Shimano pulled that low-normal stunt, so it has been quite a while. I do not know the current state of trickle-down technology, and if stable platform has made great advances in the same time frame, I thought there might be something that I do not know about these new-fangled derailleurs. There is a significant design difference between the two, and I am asking if there is anything to gain.

It has also been a long while since I posted on BF. I've been out riding bikes and have truly forgotten how to troll. Thanks for the refresher!

There is a significant design difference between the two, and I am asking if there is anything to gain.

The M772 is one of the Shadow models. You get a stronger spring, and you no longer need to worry about looping the cable like in the past. Those changes are a huge win in my book. Shimano Shadow derailleurs are what brought me back to Shimano after I had bailed to SRAM. I won't even consider buying a non-Shadow, Shimano-brand derailleur these days.

+1...I'm loving the XT Shadow.

Thanks for the info, JG... Nine bikes in the house, and I didn't even know wtf "shadow" meant :/ I did my homework, and see that it is a well-received design improvement. I'll mount up the XT and give it a whirl. There seemed to be more than tier grouping going on when I held my choices side by side, which is why I started the thread to begin with.

Maybe if I didn't buy the good stuff, I would be more literate on the new trends... Alas, years of trouble-free equipment use has rendered my knowledge dull.

Maybe if I didn't buy the good stuff, I would be more literate on the new trends... Alas, years of trouble-free equipment use has rendered my knowledge dull.

Hey, I understand. Just when I thought I understood it all, the industry spring ten-speed upon us. And I can't hardly begin to understand Rock Shox fork lineup any more...

Lately I've been doing a lot of work on Huffys and similar bikes. I'm actually becoming more familiar with bottom-bracket and other standards from 20 years ago than with the new stuff that's coming out. Pretty soon I'll be an expert in cup-and-cone bottom-brackets and those big, heavy, one-piece, Ashtabula cranks. :D

That old XTR SGS RD is one chain-slap-happy unit. The shifts are kinda sloppy, compared to the Shadows. Go XT-M772...

I use to have an XTR M953. It was the best shifting rear derailleur I ever owned, better than the XT shadow I had on a bike I just sold. I still look for the 953 to pop up for sale from time to time, but I never see them. I'd go with your 952. It's the same as the 953, except the 952 is top normal.