When I hear people talk about SRAM’s Red eTap AXS group, the detail I hear people discuss most frequently is that 12th cog. I’m going to start off this review by saying something outrageous: that 12th cog is a red herring. If you focus on that, you’ll miss the real reasons to admire (and maybe purchase) this group.

Improvements in bicycle components come in two flavors. There are those incremental improvements that just make life better and then there are those re-imaginings that take a component you thought you knew and rethink it  in a way that adds the human equivalent of a third arm.

Shimano’s introduction of hyperglide shifting falls under the first. The STI lever under the second. After riding on SRAM’s eTap AXS for a full year, I’d have to say this is one of those groups that does both rather well.

The ergonomics on these levers is the best SRAM has achieved yet.

None too soon 

I’m going on record: Multi-speed bicycles have been over-geared for most people since … wait, when was the derailleur invented? Nevermind. When I worked in shops, most bikes arrived for tuneups in one of their easiest three gears. The simple reality is that when riders are given a lower gear, they use it, and whatever the highest gear is doesn’t get used much. 

SRAM has defined a new range of gears they call X-Range. It offers four different chainring combinations: 50/37, 48/35, 46/33 and 43/30. It’s this last combination for which they should be lauded. Unfortunately, so far, I’ve only seen it spec’d on gravel bikes. The cassettes come in four flavors as well: 10-26, 10-28, 10-33 and 10-36. These latter two cassettes when combined with the 43/30 chainring combination provide gears in a range most road bikes have never really offered, save with triples. 

My one gripe here is one that has been consistent with SRAM: they always begin their cassettes with too small a cog. It used to be they started everything with an 11, but now it’s a 10. Yes, it helps that they offer smaller chainrings, but I guarantee there are riders who still won’t make use of a 43×10 gear. 

The issue here is that if they offered say, a 12-36 cassette, that would give them two cogs to stick in the middle, shrinking some of those jumps, and honestly, the last time I was spun out on a road bike I was descending Haleakala Volcano.

SRAM introduced a new chain with this group, which they call “Flattop.” The unusual link design allowed them to make a narrower chain without losing strength, but more importantly, the chain is quieter and that’s something borne out in my experience. SRAM drivetrains have had a reputation for being noisy, a reputation they’ve worked hard to shake and with Red eTap AXS, they’ve created a group that is often quieter than a Shimano drivetrain.

Noise is no basis on which to choose a group, but one of the reasons the group is quieter is that shifts are smoother. Rear shifts have never been smoother on a SRAM drivetrain. I was impressed with how well it executed downshifts under load. There’s nothing more trying for a drivetrain than a downshift made on a hill that has just grown steeper and the rider’s cadence has dropped. High power with low RPMs is no good for a chain.

Front shifts are the smoothest of any drivetrain I’ve ever encountered, full stop. That’s crazy. I’m amazed that SRAM has topped Shimano on this at all, and doubly so because SRAM has led the charge to eliminate front derailleurs. Rear shifts are also smoother than I’ve experienced with previous SRAM drivetrains.

This is perhaps the smoothest front shifting I’ve encountered.

Stop and go

I’m aware that among riders who have not yet purchased a bike with disc brakes a debate still rages about whether or not they are actually necessary, or if the evil empire is simply ramming them down our throats. Eight years ago, I counted myself among the doubters.

I’ll even grant that I questioned just how necessary they were for anyone living in a place where elevation might vary by less than a few hundred feet. I’ve disabused myself of that idea. There are two significant reasons to embrace disc brakes.

First, even if a rider isn’t interested in purchasing a gravel bike to adventure on dirt roads and the odd trail, disc brakes are a wonder for consistent brake response, e.g. in the rain. I joke that on some rainy rides I’ve hit my rim brakes and actually accelerated; I make that joke because when I expect my bike to slow and it doesn’t, the jolt of adrenalin produces the impression that the bike is accelerating. Such fun. I’ve experienced surprising braking performance lapses in dusty and muddy conditions as well. With discs, the braking is always the same.

Reason numero dos: the aforementioned gravel riding. With cantilevers a bike can accommodate 35mm tires, but rarely much more. The problem is that the farther the straddle cable is from the rim, the less leverage it has, so the bigger the tire, the worse the braking. Going with discs eliminates that problem, making 40mm tires practical.

The speed and precision of each shift is so remarkable I asked myself if I thought anyone could improve upon it.

Look ma, no wires

SRAM’s decision to go wireless makes installing an eTap drivetrain as simple as adding a water bottle cage to a frame. Actually, it’s even simpler because a bottle cage requires two bolts to be secured, not one.

Battery life with eTap is good, but it’s not so great that I can afford to forget about the batteries for months at a time; if I’m riding the bike consistently, I have to charge the batteries roughly monthly. The folks at SRAM are still surprised that I’ve managed to drain the front battery faster than the rear; that should tell us all something about the difference between the terrain in Illinois and Sonoma County. I use the front derailleur the way some people check their phones.

The one number

For anyone serious about their training, or perhaps I should say anal, one number beats all the others: power. Knowing how many watts you are producing is more important than anything else, though I will say correlating that number to elapsed time is rather important. It’s one thing to produce 800 watts. It’s quite another to produce 800 watts for 10 minutes.

For anyone wanting to train with power, one of the real advantages to buying a SRAM group is the opportunity to buy it with a power meter. The price jump is significant: the two least expensive options run about $500, but $500 for a power meter is, relative to the category, a good deal, especially considering Quarq’s legendary accuracy.

I will caution anyone who considers this option. To make use of a power meter, a rider needs to be prepared to do some very disciplined training, otherwise it’s just another number.

I challenge SRAM’s need to start all cassettes with a 10t cog.

To buy?

SRAM offers Red AXS in more variations than I can detail here. The big choices are rim brakes or hydraulic discs, 1x or 2x, and with power or without. Complete groups begin at $1350 and run as high as $4158 if you want 2x, hydraulic discs and power.

I’ve always liked the Red group, though it has had some failings; the original front derailleur was as ill-suited to its job as the Corvair was to driving. This group, however, could be improved in only two ways. I continue to wish there was a way to tell which chainring the chain is on without looking down; I’ve mistaken where the chain was more times than I’d like to admit. The other detail is, again, their lack of choice in cassettes, or alternatively, some even smaller chainrings, though for the sake of wear, I’d prefer larger cogs and chainrings.

As criticisms go, these are minor. What really matters is that when I’m on a fire road and I’m approaching a turn at a velocity I know I can’t hope to maintain for the whole of the turn, the Red brakes with 160mm rotors allow me to brake hard just before the point of entry and provided my weight is low and back, I can brake harder than I’d dare on a road bike on asphalt.

With this drivetrain I think SRAM has really executed a design that can be considered alongside Shimano’s Dura-Ace. And that might be the best compliment I can give the group.

Final thought: At the end of a year of hard riding, what stands out most is its reliability.

Join the conversation
  1. scottg says

    Campy 12, all the cassettes start at 11t, aka the spacer cog.
    So I’ll stick with Campy 10, since Campy 11 seems to be disappearing.
    I’ve Shimano 11s on another bike, to get a 12-32, you have to buy two
    cassettes. Shimano’s Geriatric Road Xtension, could use 13-34 to go
    with it’s 48/31 crankset.

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