Are Deore XT AJ, AK, and AM outer chainrings interchangeable?
10-22-20, 07:17 PM
#1
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Are Deore XT AJ, AK, and AM outer chainrings interchangeable?
I've got a 40T-AJ outer that needs replacing. Will an AK chainring swap seamlessly?
What is the difference between the AJ, AK, and AM designations?
What is the difference between the AJ, AK, and AM designations?
10-22-20, 08:45 PM
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You should stick with the same model chainring if you are just replacing one chainring. The letters are a code, based on number of chainring teeth on the crank's chainrings. That's important because the outer ring (and middle ring on a triple) has shifting aids built into the inner face of the chainring that provide superior shifting when shifting from smaller ring to larger ring. The shifting aids (ramps, pins, etc) are designed to work with specific chainring combos. Example, I have an XT double crankset (10 speed era), the original chainring combo was 38/24 on that crankset. So if I were to replace the outer chainring, I would need to get a 38t "AM" chainring, which is designed for the 38/24 chainring combo.
Last edited by well biked; 10-22-20 at 08:50 PM.
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10-22-20, 08:52 PM
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Good explanation. I'll add that for those who always soft pedal during front shifting these subtle ring to ring tooth "clockings" are of less importance then those who mash and power through a shift. These subtle ring pairings lessen chain suck and make the shift a tad smoother. Andy
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