XTR M952 chainline HELP Please.

[countryboj]

Hi all,

I recently bought a KHS 99' softail and i'm setting it up with XTR m950 group. Have a m950 112.5 mm BB and m952 crankset with a 2.5mm spacer on the BB but when run it on the middle chainring and bottom cog on the cassette, the chain just gently touches the big chainring.

Been trying to find some info of the KHS's dimensions, what lenght BB to use etc but not havng much luck.

Any advise would be much appreciated.

Few shots of the bike so you know what bike i'm talking about.

Thanks in advance

 

[Thias]

Measure the distance of the middle chain ring to the middle of the seat tube. Should be 4,5 to 5cm, iirc.
But if it would be less, I think the rings would scratch the frame.
One other thing, that pops into my mind: Maybe you could add one layer of spacers between the crank and the middle chain ring?

 

[Davichin]

http://www.sheldonbrown.com/chainline.html

With an m950 112.5mm spindle you should have 47.5mm of chain line (distance between the center of the seat tube to the middle ring):



Try to play with the spacers...

 

[syncrosfan]

Could it be that your frame might need a 116mm spindle? The XTR M950 BB came with a 112.5mm or a 116mm spindle. Measure the chain-line. If it's under 47.5 mm to the middle ring then you will need the longer spindle.

 

[countryboj]

Thanks guys really appreciate the help, just measured the chainline and it's definitely over 47.5mm 48-49mm to be exact. Would it help to put a 3.5mm spacer or would it be better to use the 116mm BB?

 

[FluffyChicken]

Re:

2.5mm spacer each side and 68mm shell,
an extra 1mm might help, would need to take tha same of the the other side though.

 

[FMJ]

At 48-49mm you don't have much more room to play with. Anything over 50 and the derailleur no longer moves the chain the right distance for the cable pull. Not (as much) of a problem in friction mode, but hell to set up properly in index mode.

 

[FluffyChicken]

Re:

Thing is it should be quite precicesly 47.5mm, that was the point of the design (and octalink and isis and now HTII).
The only thing that would make it out would be poor fitting, wrong spacers or the shell is too wide/not centered.