
At a recent MTB gathering, a group of us were circled around the new SRAM XX SL Eagle AXS transmission groupset, and as you could imagine, it dominated the discussion.
The new T-type drivetrain is making waves due to its stout-looking hangerless, direct mount interface. The latest in MTB innovation, the rear SRAM derailleur (there is and has been no front for some time) mounts directly to the bike utilizing the universal derailleur hanger interface. Like the previous AXS group, it’s fully wireless, adding to the ease of installation and setup.
There’s some cool stuff happening here. If you’re not familiar with the value add of the new Eagle AXS Transmission, the some of benefits of the rear deraileur integration to the thru-axle include:
- New derailleur/ frame interface is hangerless; the derailleur works around the center of the rear axle
- Improved durability against impacts; removing the rear derailleur hanger means no more bent hangers, poor shifting, or rear derailleurs potentially shifting into your spokes and blowing up both the wheel and derailleur
- Rebuildable rear derailleur
- Oversized lower pulley wheel
- Like the previous AXS, wireless shifting, improved ease of setup
Though the price tag may keep most of rider away, we’ll eventually see less expensive options trickling down the pipeline over the next few seasons, as more wallet-friendly iterations are eventually released.
The conversation revolved around durability, and cost. SRAM XX SL Eagle AXS lists a range of $1599-$2700 for the component group, which includes:
- Crankarm and 34T chainring
- XX SL T-Type Eagle Transmission derailleur
- 10-52t XX SL Eagle Transmission cassettee
- XX SL Transmission Flattop chain
- Pod Ultimate controller
- Power meter Variant (available)
- AXS battery & charger
The SRAM XX Eagle T-Type cassette alone runs $550, which is a lot of dough for a component that needs to be replaced regularly. That said, most of the riders in our group seemed happy with the drive trains they owned, whether it was SRAM 12-speed, or Shimano 12 or gasp, 11-speed. Fans of SRAM AXS only had one question – could they upgrade and utilize any of their current drivetrain? (here’s where those answers live, via SRAM)

What about Shimano
As a Shimano fanboi, you can bet I’m curious as to how SRAM’s biggest competitor will respond. Recently, news of a patent application filed by Shimano hit the interwebs, which looks like they’ve also got an integrated rear derailleur in the works. Though details are scarce, all signs point to direct-mount drivetrains being the future standard for mountain biking. I spent way too much time pouring over the drawings and documentation to see what the future might hold.

It’s interesting to dig in to to the patent application and dig into the documentation, and speculate on how the final product will be realized, as well as how it will differentiate itself from the SRAM transmission. The drawings appear to refer to a cable-actuated derailleur. And of course, it’s mounted on an eMTB — what looks to be a Giant Stance mixed with a Trance X “E” — and we can see where things might go.
Also interesting are the other Patents listed under “Citations” which it references applications from SRAM, and the “Electromechanical Rear Derailleur for Coaxial Mounting”.
I don’t profess to know much about patents and these legal documents, nor do I have the time and inclination to learn, but it sure is interesting to geek out on it.

The question is – will it be limited to high-end frames and bikes? With UDH, I don’t see why this would be the case.
As a rider, the widespread adoption of UDH, AKA the Universal derailleur hanger is a wonderful thing. Finally, a standard is getting adopted by the industry. If you have a box full of spare derailleur hangers for every bike you’ve ever owned, you likely feel similar, and this is a development long overdue in the bike world. Two of my Specialized bikes already feature it, and it’s nice to know the spare hanger I keep around will work on two of my rides.
As for the future, I’m looking forward to what Shimano’s take on the direct mount derailleur. Will they release it for Hyperglide Drive trains only, or also add it to the LinkGlide groups? And will they utilize the UDH standard? (would SRAM give them a license? Is a license needed to build a derailleur to the UDH frame specification? Heck if I know) Current Shimano drivetrains are compatible with the UDH hangers, but there’s no guarantee that Shimano’s future direct mount drivetrain would feature direct compatibility. (Though attempting to divide the industry with a different standard seems to be a recipe for disaster for Shimano)