KMC X12 Chain

Is anyone using a KMC X12 chain on any of SRAM’s AXS road groupsets?

I’m looking for an alternative to the SRAM flattop chains on an upcoming Red AXS build and have had great performance from KMC chains on other gorupsets 11 speed and below. The KMC chain is not of the flat top design.

I believe KMC advertise it as being compatible, but I have no personal experience.

In theory, any chain with small enough diameter rollers will work at least reasonably well because the pitch is the same.

However, there may be a slight mismatch in contact points because (iirc) the rollers aren’t exactly the same size. That could lead to accelerated wear and shifting that possibly deteriorates over time. It’s all maybes, though.

But given how long AXS chains last, and that Force chains offer most of the performance of Red at a substantially reduced cost, I personally wouldn’t be going away from that chain on an AXS build.

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KMC do advertise it as being compatible with SRAM 12 speed road groups.

I would anticipate the roller diameter to be the same since the chain is listed as compatible but I haven’t had my hands on the KMC version yet to compare measurements.

My reasoning behind installing a KMC chain over the SRAM is twofold. One - the CyclingTips article “Finding the Best Bike Chain” with data from Zero Friction showing KMC chains in general to be more efficient than SRAM AXS and two - past personal experience with solid reliability, performance, and ease of submersive wax treatment.

Someone will probably comment that if I want efficiency go with the larger chainrings and cog of Shimano. But, all that aside, I am curious about the shifting performance of the KMC 12 speed chain on an AXS groupset and more importantly the strength of the chain. The KMC does not have the “flat top” feature that SRAM tout as necessary for strength due to the thinner outer plates.

The note from the ZFC website mentions that the SRAM Road Set has smaller rollers than other chains leading to incompatibilities with other brands, though reference
to KMC is missing.

It’s a proprietary issue: one of SRAM trying to lock consumers into their consumables.

https://zerofrictioncycling.com.au/product/12-speed-chain/

KMC may be able to shed some light on the roller size issue.