AXS Functionality & Backwards Compatibility

[bobones]

BTW, another option would be to buy a 12-speed HG cassette and run AXS derailleurs and flattop chain with your current wheels and crank. I have a cheap steel 12-speed 11-34 cassette from AliE that works fine with AXS, and for a while I ran AXS with my 11-speed Red crank with Praxis Buzz 52-36 rings, again no problems.

Wait, so spacing for Sram XDR and Shimano 12sp HG cassetes is the same and everything is compatible? I must missed something

My experience relates to a Chinese 12-speed HG cassette that predates the release of Shimano 12-speed, so the spacing specification used is not clear; however, flat top chains work well with this cassette.

[gSporco]

Reviving this thread to avoid creating a new one.

I have sram red etap HRD with the corresponding calipers (https://www.fitstore24.com/en/sram-brem ... -flatmount). To make it short, can I use these red calipers with sram AXS groupset?

Thanks!

Yes no issues other than you new calipers will require the Sram Bleeding Edge nozzle for maintenance and install

I think you have replied but I just want to confirm because you mentioned "your new calipers". My goal is to NOT buy new calipers as I have these "old" sram red etap hrd calipers in a drawer.

Nonetheless, I've noticed the nozzle in the new axs is indeed different. Was that different nozzle that you were referring to?

Thanks!

The bleed nozzle is just different on the Force/ Red AXS Calipers (Sram Bleeding Edge tool).. The Rival and the older Red/ Force/Rival calipers are just a standard bleed port.. Other than that all the calipers seem to fit all the levers just fine especially the ones that use the stealthamajig hydraulic cable nipple.

Does that help?

[gSporco]

BTW, another option would be to buy a 12-speed HG cassette and run AXS derailleurs and flattop chain with your current wheels and crank. I have a cheap steel 12-speed 11-34 cassette from AliE that works fine with AXS, and for a while I ran AXS with my 11-speed Red crank with Praxis Buzz 52-36 rings, again no problems.

Wait, so spacing for Sram XDR and Shimano 12sp HG cassetes is the same and everything is compatible? I must missed something

My experience relates to a Chinese 12-speed HG cassette that predates the release of Shimano 12-speed, so the spacing specification used is not clear; however, flat top chains work well with this cassette.

I have noticed that the Flattop chain seems to shift all cassettes well.. I believe this is because its a thinner width chain.. For example my gravel/winter bike is hack job that uses eTHirteen 9-46 12sp cassette, GX Eagle Mechanical derailleur and a thumb/index shifter from Microshift, I use the Longer Rival AXS chain and it shifts like butter, way better than when I had an AXS electronic derailleur on this same cassette.. Also nearly no noise..

I have seen some videos of people using a Flattop chain on the new SHimano 12 speed cassette experiencing chain jump.. I think shimano ramps just are meant for the shimano chains..

[DaveS]

I agree that the flat top chain seems to be the most universal. It shifts well with Campy and Shimano too.