165x38mm vs 165x40mm shock....interchangeabel?

[jimmyD]

Can a 165x38mm shock be used in a frame that says its made for 165x40 (with a claimed 103mm of travel)

Im looking at a few chinese frames, one of which says it uses a 165x40mm rear shock.
My Rockshox Monarch xx shock is 165x38mm. will this be ok?

MTB specs still confuse me...

[brex]

It will fit, but you will have less suspension travel.

[xz01]

the 165mm is the only length that matters for fitting it to your frame. the smaller number is the amount of travel available to that shock.

like the above poster said, it will reduce the amount of total rear end travel available to you. i'm not sure why you'd want to do this...a 165x42.5mm shock is easy enough to find.

[jimmyD]

Only reason im interested in doing it is because I already have a 165x38mm shock. Hoping to juts replace a frame and keep all the other components.

But thanks for clarifying that for me guys!

[mtbluvr68]

165X40mm is usually a TRUNNION mount shock.  165X38 is old style hardware, so you might need to fine hardware that would work with old style shock. 

[Barkything]

165X40mm is usually a TRUNNION mount shock.  165X38 is old style hardware, so you might need to fine hardware that would work with old style shock.

Any Idea which brand/store makes trunnion conversion kits to use 'old' 165x38 shock?