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new M760 cassette not compatible with CK hubs?

3K views 12 replies 7 participants last post by  noshortcuts 
#1 ·
I had 11-34t XT M750??? shimano cassette on my CK hub. Decide to replace it with new M760 XT 11-34t and I need a spacer before placing the cassette if not it's all loose!!!??? and I think that the spacer is messing with the chainline... any thoughts????
Thanks guys:thumbsup:
 
#2 · (Edited)
Ahh, after some careful searching I found the thread that discusses this in depth. You should read it.
http://forums.mtbr.com/showthread.php?t=176064

There are also a couple reviews documenting similar problems on this website, one of which I wrote myself. That said, I just bought yet another XT cassette after the last one got bent again. The solution might be to go SRAM.

If I remember correctly the conclusion is that the last (smallest) cog on the M760 cassettes is not machined precisely enough to fit on an ultra-precise CK driveshell. The notches arent deep enough so no matter how tight you tighten the lockring, the smallest cog can't tighten against the other gears, just against the end of the driveshell.

Some people were recommending you take an old 11 tooth cog from another cassette that did fit properly. I've gone the spacer route on multiple cassettes and have had marginal success. I have had the cassette come loose before, and this may have caused the issues I've had with bending the larger XT cogs. My theory is that the cassette worked its way loose, then in a high-torque situation the loose cassette moved a little on the driveshell and off the chainline. The chain then pulled the cog at an angle and bowed the cog outward.

Another problem I've had, which I blame on the lightweight aluminum CK driveshell, is the shell getting notched by the gears digging into it. The shells just aren't very strong. It takes a screwdriver for me to pry off cassettes on my notched driveshell and some gentle taps with a mallet to get the cogs back on. The driveshell only gets notched on the higher gears that are not attached to the load-distributing spider like the low gears.

These days I just check that my cassette is tight frequently. Of course this hasn't solved all of my problems since I had this happen again a couple weeks ago (bent cogs on a M760 cassette).
 
#4 ·
nothing...

I tried the old 11 tooth cog and it is still VERY loose:madman: :madman:
Dunno what to do:confused:
I have read that the spacer don't place equal load on the shell on the CK hub and I'm afraid of f*&% it. Also, it would mess with the chainline WTF????
 
#5 ·
BBW said:
I tried the old 11 tooth cog and it is still VERY loose:madman: :madman:
Dunno what to do:confused:
I have read that the spacer don't place equal load on the shell on the CK hub and I'm afraid of f*&% it. Also, it would mess with the chainline WTF????
did you try the spacer? it is very thin. My M760 is nice and tight on my ISO Disc with a 0.3 mm spacer...

http://www.speedgoat.com/product-popup.asp?part=115011
 
#10 ·
If you take that same cassette and install it on any other hub it will work fine, the problem is actually in the King hub shell, yes I know it sacriligious to say but its true.

I had a stack of 0.5 spacers I use to cure the problem for my customers. You can also use these same spacers to actuaaly help your chainline. If you have a 50mm front crankset (all new 2 piece cranks) you can use these up front and in the back to help realign the chain line, its amazing what a half a millimeter can do.
 
#11 ·
XTR and CK ISO have play

I just put an xtr cassette on a new CK ISO hub and there was a bunch of play. I took it off, greased it better, and re-tightened and there is less play, but still play. The xtr seems to fit very loosly notch for notch with the CK......... guees I'll look for a spacer to see if that does the trick.
 
#12 ·
WTB LaserDisc Lite hubs have this problem with Shimano cassettes as well. They actually ship with the spacer.
 
#13 ·
Summarized problems and solutions with XT/XTR cassettes

Bob the Wheelbuilder said:
WTB LaserDisc Lite hubs have this problem with Shimano cassettes as well. They actually ship with the spacer.
Great of WTB to provide a solution to Shimano's problems. I wish CK was so on top of it!

What really kills me is that the problem is with Shimano!

I have a very expensive XTR cassette that is too loose laterally and rotationally on either a DT 340 or CK ISO hub while SRAM fits nicely.

In general in the forums and based on my recent experience
here is what I gather concerning these problems and available solutions:


The problems are with "60" series Shimano cassettes (XT or XTR) and many hubs (except Shimano's own).

First Shimano problem: the small 11T cog does not sit low enough to tighten down on the rest of the cassette. This creates lateral play. There are four solutions:

  1. Buy a SRAM cassette instead.
  2. Use a .3-.5mm spacer behind the cassette so the 11T cog can tighten properly. For good measure, use a Chris King lock ring becasue it has more threads to better engage and tighten.
  3. Use a different brand 11T cog with your Shimano cassette to make it work.
  4. File down the top of the flanges on the hub so the 11T cog sits lower.

Second Shimano problem: the spaces between the flanges are too loose so there is rotational play between the cassette and the hub.

This problem is reduced by the above solutions but not solved.
 
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