SRAM has always been a leader in innovation in the road and triathlon space. From humble beginnings, SRAM has become something of a superbrand, growing to a full-line component maker, and so large that it acquired several companies in the process, including Quarq, Zipp, and others! We have always loved SRAM and the brand ethos, but we weren't always smitten with the eTap system. Until now. SRAM's latest offering, SRAM RED eTap AXS (which we will just refer to as AXS), is a whole new ballgame. It truly changes the game in terms of what a top-shelf groupset can be, as well as offering important innovations for drivetrains in general, including an amazing new experience in the 1x space.
SRAM's wireless eTap system offers a compelling alternative to Shimano's popular Di2 drivetrain.
We have cobbled together our own eTap 1x system in the past, and the draw is simple: fewer parts, more simplicity, and ultimately an easier time for the rider. You can just shift up, or shift down. No need to worry about a front derailleur, or a front shifter. Just up or down. But our homebrew solution had drawbacks. Most importantly, with no derailleur clutch, we were more liable to drop a chain. And of course, 11 speeds is fewer than 12. The solutions AXS provides are absolutely brilliant. The rear derailleur liquid damping does an awesome job of preventing chain drop, and the 1x-specific chainring tooth pattern does as well. The system is simple, minimal, effective, and beautiful. And there are a lot of reasons for it. We will get to those on the next page.
The most obvious change to AXS is that it is a 12-speed group. But that is actually the least of its differences from the previous eTap Red 22 group. More significant than the number of cogs, AXS offers a 10-tooth cog as the steepest gear for the rear cassette, which makes so much of the AXS benefits possible. A 10-tooth cog isn't possible on a standard Shimano/SRAM freehub body, due to the geometry. Smaller cogs required the development of an entirely new freehub body, dubbed XDr, which is still relatively new but which (I believe) will become a de-facto standard as its benefits become clear to SRAM's consumers and competitors alike. Unlike BB standards (and we'll get to this later), this new freehub body offers a real, substantive improvement over its predecessors. To wit, it allows us to finally go below the 11-tooth barrier. In AXS, this means cassettes that all have a 10-tooth cog as its smallest member. 3T has already taken advantage of this same format and made an 11-speed cassette with a 9-tooth cog. More on these ratios and the relevant math later.
Obviously, the headline here is that we are very impressed with SRAM's latest offering. AXS leverages the impressive technology SRAM has developed in the past on both the mechanical and electronic sides, while at the same time offering significant improvements for individual components, and making big strides for the functionality of the system as a whole. We have a lot to say about the group, so hit the jump and read on.