[mickster4]

Anyone know what the difference is in markings on crankrings? I have an xt 38/24. My front derailleur just doesn’t seem to be shifting smooth. The lbs replaced my 38t with an xtr 38 “ah” while my 24t is an “am”. Looking up new rings there is ak, aj, etc. what is the difference? Is there a compatibility issue between an ah and am? Shouldn’t I have the same letters?
Thanks Mick

 

[arnea]

Yes, big chainrings have different ramps for different small chainrings. Definitely get a correct big chainring for smooth shifting.

 

[noapathy]

Yes, maybe. 38/24 AM, 38/26 AK for XT. XTR has different letters, but since I cannot afford it I don't remember. The only XTR "ah" rings that show up in a quick google search are the 38 and 26. I suspect it'll work fine, but maybe someone else can confirm.

 

[mickster4]

Yes, maybe. 38/24 AM, 38/26 AK for XT. XTR has different letters, but since I cannot afford it I don't remember. The only XTR "ah" rings that show up in a quick google search are the 38 and 26. I suspect it'll work fine, but maybe someone else can confirm.

You are correct! LBS replaced my ah ring with one stamped am to match the small ring and it shifts perfect now. I never knew these were matched sets, I always thought a ring with the same amount to teeth would work but arnea was correct the ramps are different. Thanks guys!