Photo: Greg Heil

If you haven’t heard of SRAM’s new 1×12 Eagle drivetrain yet, you’ve probably been living in a van, down by the river, with no cell reception. Not that there’s anything wrong with living in a van down by the river and just riding your bike every day, but if you want to catch up on the hubbub, read this article.

I recently had my first chance to ride SRAM Eagle and to form some opinions about this new drivetrain. Read on for my take.


XX1 Eagle comes stock with the visually-impressive gold-colored 10-50 12-speed cassette. I can guarantee you that you won’t understand how big a 50-tooth cog is until you see one in person–it’s absolutely massive! Seriously, go to your local shop with the blingiest bikes and check it out–it’s astounding.

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Photo: Greg Heil

You can choose which chainring to run up front, like any old 1x system, but the stock is a 32-tooth ring.

SRAM claims to have updated basically all of the internals and mechanical do-dads that make the shifts happen, but at the end of the day (or the beginning, for that matter) the drivetrain works the same as any SRAM 1x drivetrain: you can only press the shifter with your thumb, the derailleur clutch keeps the chain taught, and the narrow-wide chainring help keeps the chain from popping off.

The total weight of the XX1 Eagle drivetrain is a very respectable 1,456g, and total cost is $1,417.

Out on the Trail

Photo: Devon Balet. Rider: Greg Heil

Photo: Devon Balet. Rider: Greg Heil

I tested the Eagle drivetrain over the course of two days aboard the brand-new Scott Spark Plus in Crested Butte, CO–more on that later. My testing consisted of downhill laps at the bike park and an epic 23-mile backcountry ride on the iconic 403 and 401 trails.

While not a long-term test, in no way did I take it easy on this drivetrain! On day two for our epic backcountry ride we awoke to blankets of gray clouds, with rain beginning to fall minutes into our ride. While the dirt on the trails held up well to the moisture, the moto’ed-out low spots filled with water, making for soupy mud puddles and a constant coating of grit, muck, and general nastiness.

Through every situation that I piloted the Eagle, it shifted superbly! The shifts were some of the crispest, most reliable I’ve ever felt from any drivetrain, period. There was no ghost shifting, no searching for gears, and almost no complaining whatsoever.

At one point, I did get the drivetrain to squawk at me: when accelerating out of the saddle, up out of a mud hole, on a stupid-steep hill, and attempting to downshift three gears at once. Ultimately it was a bad call on my part, and while the drivetrain crackled and groaned under pressure and from grit in the gears, it made the shift successfully, allowing me to complete the slippery climb instead of having to get off and push.

Gear Range

Speaking of getting off and pushing, the first question that came to my mind when I start pedaling Eagle was, “how will the 50-tooth cog feel on the climb?” And the honest-to-goodness answer?

SRAM’s video about the death of the front derailleur isn’t hype.

It really isn’t.

With a 32-50 low gear, when I did end up getting off to push, I had to be honest with myself: it wasn’t the gearing range. It was the fact that I need to be in better shape.

While perhaps my 2×10 drivetrain might have a bit lower gear than the Eagle drivetrain I was riding, a 32-50 low gear should be plenty low for almost any climb known to man. And if it isn’t low enough for you? Drop to a 30-tooth cog, or even a 28. You can achieve an absolutely insane low end, without the added complication, weight, and reduction in chain retention that all come from a 2x drivetrain.

On the high end, Eagle provides a high gear equivalent to a standard 1×11 drivetrain. However, if you find that you’re having issues with getting spun out on the high end or that you ride flatter trails and a 32-50 is basically never usable on your local terrain, you can easily bump the front chainring up to a 34 or a 36, which will then provide a high end speed that’s much higher than a 1×11, but a low-end that’s comparable to what a 32-42 will provide.

What about that low-hanging derailleur?


Photo: Greg Heil

Some internet commenters have mentioned that the long-hanging derailleur could get ripped off easily. And while it does appear to hang low, even on black diamond backcountry trails and full-on DH runs at the ski resort, I had absolutely no issues with catching the derailleur on rocks or any other sort of trail obstacle.

In my opinion, anyone voicing this as a charge against Eagle A) hasn’t ridden this drivetrain yet, and B) has conveniently forgotten how long derailleur cages for 3x drivetrains used to be.

Would I buy it?

When 1×11 hit the scene, it was rightfully lauded as an excellent advancement. However, I always found 1×11 to require a cost/benefit analysis: should I trade some of my gear range for better shifting and chain retention, or focus on a broader low end and high end range?

With Eagle, you don’t need to make a gear range sacrifice to get an excellent chain retention and drivetrain performance benefit: you can get it all in one package! But right now, that package isn’t cheap. So the question is, “would I buy it?”

Honestly, I can’t see myself upgrading the drivetrain on any of my bikes anytime soon. The reality is that my drivetrains do a pretty great job the way they are, and I can’t really justify a $1,400 upgrade to fix a problem that is barely there. I’m waiting for Eagle to come down in price.

But as I consider my next bike purchase(s) a year or more down the road, would I buy a new mountain bike that doesn’t have a 12-speed drivetrain? And the answer to that, friends, is “probably not.”

After my time on Eagle, I can agree with SRAM’s assertion that 1×12 is the future, and that the marketing isn’t hype. If my next bike has more than one speed on it, it will need to be a 1×12.

# Comments

  • MTBrent

    Good stuff, Greg. I’m still in the dark ages and ride a 32 x 11-36, but honestly have no real complaints. Personally, 50 teeth sounds (and looks) ridiculous, though I’d love to try it to see what kinds of techy climbs could be conquered. Combined with those plus tires, fitness must truly be the only limiting factor.

    Also, that exact bike has made its way onto my short list of “next bikes.” Looking forward to hearing your thoughts on it…

  • skelldify

    If you need a 500% gear range on an all mtn bike, you’re doing it wrong.

    • Joel DH

      more like ridiculous…

  • sshafer1

    I’ve been riding a 2017 Stumpjumper Pro 6Fattie for a week and a half and I really love the 1 x 12. I’m a 220 lb mountain goat, so I did switch to a 30T Absoluteblack oval as soon as I got the bike. I love to climb and for the steep stuff where I live, this is my perfect ratio. Oh so slightly easier than the 28-42 granny that I’ve been using, but lots more on the high end so I’m not spinning out as much. I agree with Greg in that I don’t need it, but it sure is nice to have!

  • ronb

    I’m happy with my 1×11 Stumpjumper carbon 650b fattie’s 28t-42t low end, but not quite. And certainly I’ve realized I’m able to stay in the higher low end range–higher than my 2×10’s low end–because I don’t have the front derailleur shifting episodes to deal with, and can crush it on those transitions up the hills. Just the one thumb click, click, click, click…click-click-click-click…But if not making the top, rolling over those 175mm crank arms while on the 42t can burn on the steeper stuff. So I’m strapping on the 1×12 to the Stumpjumper, and moving the 1×11 drivetrain to my old GT Avalanche hardtail. I agree the top end is rarely an issue on the trails I ride. And I do like a good granny gear when I’m weak, or back on the bike from a long off period. I’m going with the 30t with the 10-50t X01 Eagle version–cause the XX1 is too much bling for my taste…And I did a bit better than $1400. If you have more patients than I did that will go down. P.S., fatties rule in the pure fun category!

  • ronb

    And if you’re an uphill as much as downhill rider like me, GET a dropper post! There’s lower sweet spots for dropping into those downhill turns, and a leg saver top position for the climbs. The Specialized Command Post has been working fine for my heavy body beating it up for months now. Heard some issues with them, but that was more than a year ago. Maybe Specialized listened. If you do have issues with unsolicited drops and crotch pops, and it’s not air pressure, check, or have the mechanic check, the cable length. My initial adjustment was off, and a tweak made it solid…

  • BentChainRing

    After having used a 1-by for a while I finally went back to a 2-by. I just could not tolerate the lack of gear choices when climbing. Having 4, 5 and 6 tooth jumps was just too much. Now they are promoting this giant 50 tooth pie with an 8 tooth jump from cog #2. Not for me. I like a bit closer ratios such that I can attempt to maximize my speed and/or pedaling efficiency. I have gone back to having a front deraileur. It’s worth it to me. Derailleur reliability these days is very high. Getting caught in between gears where one cog is too hard, but the next up is too easy, while the rider ahead of you pedals away sucks. But maybe that is just me? Hell I even like riding my old bike with a triple just to have 1-2 tooth jumps when working the small ring while passing people stuck in a one choice big pie.

    • ronb

      Not buying it. My 1×11 shifts great. I moved it off my fattie Stumpjumper on to my old GT hardtail. It’s great on that too. I put the 1×12 on my Stumpjumper–fantastic! As soon as I moved to a 1x system, I immediately found I was more efficient. And at my age, I’m all about efficiency on my bikes. I mess up the gear transitions much less with a 1x. The ratio changes are plenty good. I keep my momentum in the climbs better, requiring less shifting, and staying up in higher gears. I don’t notice more, but less, shifting clunkiness and stress shifting. I chase my friend, an mtb racer with 20+ years on me, all over the STs, and hang with him fine, oddly enough. Admittedly, that 50t really allows me to spin up the steep stuff. The 1x has actually increased my endurance. And, sure I’ve all but stalled on a few snappy steep climbs in too big a gear on my 1×12, but I’ve done the same on my 2x10s, if not more often. All my fault in poor shifting. You can actually downshift earlier with the 1x’s, and often upshift sooner with the momentum gain topping out. And with any multi-geared drivetrain, you should tune your derailleurs before every big ride. So, based on my personal experience, I’m not buying the 2x argument. And I’m certainly not going back.

  • Joel DH

    I run a 1×8 gear range and don’t see a reason to upgrade. Shifting is just shifting. On the steep climbs, I leave it in the granny or the second cog and suck up the hard parts. If I slip, I just walk partway back down the hill to look for a spot to get back on and try the section again. I always say, its not the bike; its the rider.

    • ronb

      I use to have powerful, suck it up legs; nothing too painful–steep or long–I couldn’t crank up. Now I’m 60+ and have a 50t crutch, and still loving it!

  • RoadWarrior

    Just laid hands on my new bike with 1×12 yesterday. Parking lot shifting was perfect!
    As I might be in Santos one day, and doing 1,500′ 10-20% grade climbs in Va the next. (What I’m doing this morning) the huge range is a necessity. And not hitting the front shifter when going for the dropper post,,,, priceless.

    • ronb

      Agreed! Simplified cockpit…dropper posts, yessssssssss.

  • Willis9259

    I’ve been running an 11 speed 42T and with the steep rocky/root infested climbs in NWA I’ve needed more gearing. Just ordered the Scott Spark 2017 with Eagle… can’t wait to try it out! Not real sure what Sram was thinking with the gold bling. Don’t mind the gold or titanium on the cassette but the gold xx1 just isn’t my thing… black and red baby!!!!!

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