# XTR M900 Question ... SGS rear hub?



## holden (Jul 27, 2004)

hello. i picked up a XTR M900 group that had a rear derailleur with a long (SGS) cage, which i hadn't seen before. it had a sticker that said "DESIGNED FOR USE WITH FH-M900-SGS". on the 32-hole rearhub was a sticker that said "DESIGNED FOR USE WITH RD-M900-SGS".

what is the difference in the FH-M900-SGS versus regular rear hub?


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## holden (Jul 27, 2004)

follow-up: first flight chart mentions in 1995 a M910 long cage RD, so i suspect someone put that cage on my M900 RD body. maybe?

edit: nevermind...it definitely is a M900 long cage


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## DeeEight (Jan 13, 2004)

I was gonna say, the 900 XTR only came as a GS cage as far as I EVER saw any bike spec'ed with... the funny part, being even with the smaller 12-28 block, and the 26/36/46 chainrings... that still exceeded the total chain capacity (33T) of the GS cage derailleur with its 10T pulleys by 3T. 

And yet...just about every bike spec'ed with XTR used the 12-32 cogset.


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## mojo_matic (Jul 15, 2007)

Thought this was a bit interesting. Read online that M900 XTR rear derailleur was only available with medium cage.

The M900 rear derailleur that came equipped on stock 1993 Trek 9500 is long cage. Same decals described by holden, "DESIGNED FOR USE WITH FH-M900-SGS." Same decal is also found on the rear hub body.

For what it is worth:

Cassette is the champaign colored HG M900 cassette. 12-28! Go figure! 

Crankset is M900, "Dual SIS compatable," with SG rings (SG-X large ring). 26, 36, 46.

Chain is HG, marked both Dura-Ace and Narrow.


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## Guest (Oct 6, 2007)

havent heard about the SGS hubs but i think those long cage m900/910 rear ders were meant to be used on tandems and has 38t capacity. so maybe the hub is modified into that direction too? larger bearings or 40 holes or a stronger ratchet mechanism?


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## mojo_matic (Jul 15, 2007)

Derailleur is not m910. Marked M900, and still retains the old return spring (i.e. 7 speed XT, not m910 and m950+ XTR). SGS cage has the sticker, no etched markings of any kind (as with M910). 

The hub not anything special. Ho-hum M900 (as far as I can tell from comparison to another M900 hub). Same bearing count. As far as the cassette being "heavy duty," I don't know. Ratchet does not feel nor sound like anything special. 

As stated before, drivetrain came from stock Trek 9500. 

The medium cage may not have been best choice for 12-32 cassette. Interesting that the 9500 was sold with 12-28 cassette, yet came with SGS derailleur. 

M910 came out around 1994, and the Trek was a 1993 model. I'm guessing we have an example of a brief overlap between the M900 and M910 deraileurs. 

IG, HG, blah bah blah..... Anyone who has torqued on a bike knows that for the most part, everything works together (unless you go to extremes, like matching 7 speed and 9 speed componants...and even then, no issues may be found, as with my short cage 730 XT rear derailleur mated to 9 speed Dura-Ace cassette and rings). Shimano is always looking for ways to milk a few more cents out of the consumer. Of course, the US consumer is always ready to bite! Woo-Hoo........


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