XTR M900 cassette question

[Killer_V_900]

I have a M900 front and rear derailure and M900 shifters, but no cassette.

I have found that there are two different m900 cassettes.
I am looking at the 12/28 versions. There is a P type and a Q type.
I am looking at getting this one,
Shimano M900i type Q 8 speed cassette.
Will this work?

What is the difference and what do I need for my bike?

Here is my bike http://www.retrobike.co.uk/forum/viewtopic.php?t=124673

 

[sinnett177]

The spider type is the difference, think the Q has a larger ratio also.

 

[FluffyChicken]

12-28 and 12-32 is the difference.
The 'I' is a lot harder to find, but it's been Interactive Glided (IG) aka in 8 speed and beyond.. to have ramp/profile on the rear sides of the sprockets not just to front. Also it's riveted on (so ignore a comment to come)

You can pick up a new SRAM PG850 cassette and that will work fine or my preference is CS-M737's as they well the same and come in 11-xx ratio's (they're also more robust in my opinion of going through many M900 BiTD as the bolts don't come loose, though I do have one with loose rivets)

Have a gander here for some pics, http://members.home.nl/children-of-the-korn/XTR900.htm

Also if that 7speed cassette doesn't have a spacer behind it (about 3.5mm ?) then you'll need a new wheel/hub

 

[Killer_V_900]

Thanks, They are both available in 12/28 and 11/32. So the 900i will shift better? Yes my 7 speed does have a spacer installed.
I have a M737 that my friend gave me. I just wanted my bike to be all XTR

 

[FluffyChicken]

Thanks, They are both available in 12/28 and 11/32. So the 900i will shift better? Yes my 7 speed does have a spacer installed.
I have a M737 that my friend gave me. I just wanted my bike to be all XTR

It will shift slightly better going don the cassette. Well I noticed it between my M737 cassettes (they came in both as well)

M900 not 11/32, just 12/32
P type = 12-32
Q type = 12-28

You're looking at good money for M900 even used one's
M737 go for around £20 give or take £5
M900 can go for silly money now £60+ if new, even used seem to fetch £40+
as it the way for a number and a coating that flakes off and a lack of 11 tooth.