RH one-by crankset & SRAM flattop chain?

[sparky33]

Does anyone know if the Rene Herse one-by crank chainring is compatible with the SRAM flattop chain? Has anyone tried this combo?

iirc, the stated 12-speed compatibility is in reference to SRAM Eagle 12 speed since that compatibility statement predates the release of AXS flattop chains.

[charliedid]

I'm just guessing....yes.

[.RJ]

Originally Posted by charliedid

I'm just guessing....yes.

the sram axs chain uses larger rollers, so dont be so sure

https://www.velonews.com/gear/techni...compatibility/

[sparky33]

Originally Posted by .RJ

the sram axs chain uses larger rollers, so dont be so sure

https://www.velonews.com/gear/techni...compatibility/

Exactly, this detail is the subtext of my question. Most 12s chainrings’ tooth profile have to be reworked to deal with the rollers, for example Wolf Tooth drop stop B vs A.

[ripvanrando]

SRAM flattop chain has non-standard roller sizes and it is not going to work with standard chainrings. Sort of like the 29.9 mm bearing on the crank. Both done for scientific aka marketing reasons.

[sparky33]

I found an answer to my original question.

Rereading a bit of Bicycle Quarterly issue No. 77, I came across the review of the XPLR group. Jan describes running the drivetrain on his Firefly with the Rene Herse cranks where the RH “One-By ring harmonizes perfectly with SRAM’s flat-top chain.”

It’s a bit of a surprise for reasons discussed in earlier posts, but found cross-compatibility is always appreciated.

[AngryScientist]

That's good to hear. Spurred by the recent thread about the excellent wear and long life of the sram flat top chains i bought one to try out on one of my campy franken drivetrains and see how it plays along.

A lot of the times, you can read all about compatibility, but sometimes if you really want to know you just have to try it and see how it works.

[sparky33]

Originally Posted by AngryScientist

That's good to hear. Spurred by the recent thread about the excellent wear and long life of the sram flat top chains i bought one to try out on one of my campy franken drivetrains and see how it plays along.

A lot of the times, you can read all about compatibility, but sometimes if you really want to know you just have to try it and see how it works.

You are a mad-scientist.
It would be amazing to learn how the Ekar cranks work in a flat-top drivetrain, especially given the dearth of SRAM 1x AXS cranks and such these days. Ekar cranks are a couple ticks nicer than other third party options.

[Dave]

Originally Posted by sparky33

You are a mad-scientist.
It would be amazing to learn how the Ekar cranks work in a flat-top drivetrain, especially given the dearth of SRAM 1x AXS cranks and such these days. Ekar cranks are a couple ticks nicer than other third party options.

The Ekar chain is significantly narrower between the inner and outer plates compared to an axs chain. The axs chain would fit over the Ekar chain rings, but would have a loose fit.

The roller diameter difference has never caused a problem for me, using the axs chain with Campy 12 cranks and cassettes and shimano grx cranks with axs cassettes.