2017 Sram GX Eagle Drivetrain

Long-Term Update — 2.10.18

Last summer, I reviewed the newly released Sram GX Eagle drivetrain, and the long and short of it was: it’s a lot of bang for the buck. You get all the upsides of ditching the front derailleur with the fantastic gearing range of the 12 speed Eagle cassette, and at around $500, the whole kit is priced to sell.

But drivetrains wear out, so the big question was: how would the GX Eagle bits fare over the long term?

Throughout my time on the drivetrain, I had it mounted to the Santa Cruz Hightower. I had the chance to ride a couple other bikes with GX Eagle drivetrains, and nothing on those short rides did anything to change my initial impressions. But for this long-term follow up, I’m basing it entirely on my time on the drivetrain mounted to the Hightower.

All told, I put about 1,000 miles on the drivetrain, with probably somewhere in the neighborhood of 150,000 feet of climbing. Conditions ran the gamut — everything from dry and dusty to wet, muddy, and occasionally snowy.

I’ll offer the caveat that I’m not a huge guy, and I don’t lay down the kind of drivetrain-destroying wattage that some people do. But among a large group of riders, I’d guess that I put a fairly average amount of wear on the drivetrain.

Getting To The Point — How’d It Hold Up?

Pretty well in most respects. First, the high points: after all those miles, everything still shifts really nicely. There hasn’t been a substantial degradation in shifting performance in the time I put on the drivetrain (although the derailleur died — more on that below). The shifter is still working like new. The cranks have some rub marks from my heel, but they’re otherwise going strong. They’re still spinning smoothly, and despite smashing them on a bunch of rocks, nothing bad has happened.

Chain and Chainring

The chainring and chain are probably the pieces of the drivetrain that I’m most impressed with. The ring is still running smoothly, quietly, and it still holds the chain well. Sram made a bunch of tweaks to the tooth profile that look kind of weird, but the idea was to improve longevity. And from what I can tell, those changes worked really well — I’d say the chainring is lasting longer than any other narrow / wide chainring I’ve used from any brand.

Here’s a picture of the chainring in its current condition — I’d say it’s showing very little sign of wear.

Noah Bodman reviews the Sram GX Eagle Drivetrain for Blister

Sram GX Eagle Chainring

The chain is also still going strong. Now, I was using an X01 Eagle chain rather than the GX Eagle chain, so this isn’t an entirely fair test. But I actually have a bit more miles on the X01 chain than the rest of the GX Eagle kit, and it’s still in great shape. I stuck a chain checker on it and the wear indicator is sitting between “like new” and “very good.” So I’d say the chain is holding up better than average.

Cassette

The cassette is also doing pretty well. Like the chainring, there’s a very small amount of visible wear, mostly on the top two cogs, but I’d still call it quite good. Overall, I’d say the cassette is wearing on the “good” side of average.

Noah Bodman reviews the Sram GX Eagle Drivetrain for Blister

Sram GX Eagle Casette

One odd issue that I did encounter with the cassette is that, as the cassette, derailleur, and chain broke in and tolerances became a bit less tight, there was a singular tooth on the 9th cog of the cassette that would interfere with the chain while I was in the 8th gear. One tooth lined up in a way that bumped the chain in that one gear combination, which caused the chain to skip. I think this is mostly an issue due to the cogs being spaced so closely together — it’s not something that I’ve ever experienced on any other cassette. Once I figured out the issue, a slight bend with a screwdriver to the offending tooth solved the problem.

You can see in this picture how the chain sits very close to the tooth on the next cog down. (And yes, I know I should have cleaned my drivetrain before putting the bike away for the winter. I’m a terrible person.)

Noah Bodman reviews the Sram GX Eagle Drivetrain for Blister

Sram GX Eagle Casette — Closeup

Derailleur

And that all brings us to the derailleur, which is the one place where I had a significant issue. As I noted in my initial review, the initial setup is a bit fussy — when the spacing between cogs is this narrow, there’s less room for slop, and the adjustments need to be pretty close to spot on. It also means the drivetrain is less accommodating if the derailleur is slightly bent or a little out of whack.

Adding to this issue is the fact that the derailleur sticks out from the frame quite a bit, and the wide gear range necessitates a long derailleur cage that hangs pretty low. All that means that the derailleur is fairly prone to damage.

And, as could be expected, I eventually smacked the derailleur on a rock and bent it. The derailleur wasn’t visibly mangled, and initially, I couldn’t tell if it was the derailleur or the hanger that was tweaked (a quick hanger alignment confirmed it was the derailleur).

Once it was bent, the drivetrain still more or less worked — it was just a bit unhappy in 2 or 3 gears (and I could use the barrel adjuster to select which 2-3 gears were going to be skippy). This was annoying, but given that I’m lazy and try to avoid wrenching on my bike until it’s absolutely necessary, I continued to ride it like this for a while.

Noah Bodman reviews the Santa Cruz Hightower for Blister Review

Noah Bodman with the Sram GX Eagle Drivetrain

But eventually, I sucked a stick and a bunch of tall grass into the derailleur cage, which bent things even more. And while I could still ride the bike, it reduced my usable gears to 3 or 4. Efforts to straighten and otherwise correct the derailleur were unsuccessful, so it was time for a replacement.

On one hand, both the initial impact and getting a stick caught in the derailleur likely would have damaged most other derailleurs too. I don’t think the GX Eagle derailleur is exceptionally fragile; it just succumbed to normal, derailleur-ending events. That said, I also think a lower-profile derailleur (like some of the older Srams, or many of the Shimano derailleurs) might have escaped the impact either unscathed or less scathed. And I think the extra length of the GX Eagle derailleur probably contributed to picking up the stick that bent it. A shorter, more tucked away derailleur might still be going strong.

And given that the bend in the derailleur wasn’t massive, I’d also guess that drivetrains with more space between each cog (i.e. 10 or 11 speed systems) might have been better able to accommodate the out-of-whack derailleur.

I’d also add that I’m skeptical that any other level of Eagle derailleur would have fared differently. I don’t think this is a problem with the GX Eagle derailleur bending easily, and I doubt that if I’d been running an X01 Eagle or XX1 Eagle derailleur, the outcome would have been different. In other words, I don’t think spending more money would have solved this particular problem.

Bottom Line

My long(er) term test of the GX Eagle drivetrain more or less confirmed my initial conclusions — the biggest liability of the system is the derailleur, which is somewhat injury prone and the system is not particularly accommodating to a mechanism that’s out of alignment.

But that doesn’t get around the fact that the gear range is fantastic, the rest of the system performs impressively well (and wears well), and the price is still pretty damn competitive. It’s easy to poo-poo the system because I bent the derailleur. But I’ve been destroying derailleurs since the days of 8-speed, so that really isn’t anything new. And the dinner plate rear cog gets me up climbs that I’d otherwise walk.

So, are you the kind of person that breaks derailleurs a lot, or is your bike rarely in a state of proper adjustment? The Eagle drivetrains might be a frustrating experience for you. Do you live somewhere flat-ish, where the huge gear range isn’t really necessary? Then yeah, Eagle probably isn’t the answer to whatever your woes are. Do you have an ongoing, somewhat irrational love affair with the front derailleur? I think you are a bit odd, but I know from experience that no amount of rational argument will get you to change your mind. Are you just itching to talk about the e13 cassette in the comments? Agreed, those are sweet. But they have their own durability issues, and they cost more than a GX Eagle cassette.

Long story short, after a lot of miles, I still think the Eagle drivetrains make sense, and I still recommend it. Yes, there are downsides. But getting that kind of range out of a 1x system is fantastic, and at least for me, the upsides outweigh the downsides. As I said in my initial review, when it is set up correctly, the GX Eagle offers most of the performance of it’s more expensive siblings at less than half the price, and that’s a helluva thing.

11 Comments

  1. Blister Member
    Tom July 5, 2017 Reply

    Nice review. I think that SRAM 11-speed 10/42 really hurt Shimano. They were awfully late to the party with their 11/46 cassette.

    GX Eagle 12-speed 10/50 is going to eat their lunch.

    This from a long-time Shimano fan (and still my preference for brakes).

  2. Andy M. July 7, 2017 Reply

    What X01/GX combo would you do for a value/weight/noticable shifting?

    From what you posted, I’d guess GX RD & chain, X01 shifter & cassette.

    • Noah Bodman Author
      Noah Bodman July 8, 2017 Reply

      Hey Andy,

      Yeah, I think that’s probably the combo I’d go for. The cassette is the big question – you save a bunch of weight, but it costs a fair amount more. If the budget was tight, I wouldn’t hesitate to stick with the GX Eagle cassette.

  3. Marcel July 8, 2017 Reply

    I’ve seen some comments the GX RD got some improvements over XX1 and X01, but not sure what, just like the XT Di2 over XTR. Can’t remember now what was it… so a GX RD/Chain + X01 Cassette/Shifter seems a great combo getting the best of both worlds.

  4. ben camertog July 10, 2017 Reply

    Any issues with creaking yet? Almost everyone I know with a pinned SRAM mountain cassette eventually gets unfixable creaks as a few pins come loose enough to move around just a little.

  5. Blister Member
    Tom August 13, 2017 Reply

    Hey Noah, any issues with one-tooth skips on the especially 3 to 2 shift, and also occasionally on the 2 to 1?

    My new XX1 is set up perfectly, but still has this issue on about one of every five shifts from 3 to 2. Seems related to the odd (to me) decision by SRAM to make the 2 and 1 cogs narrow wide. If the ramp grabs the wrong link, the chain ends up mis-timed by on tooth, and has to skip forward to get down onto the cog.

    Thanks!

  6. Noah Bodman Author
    Noah Bodman August 14, 2017 Reply

    Hey Tom,

    My shifts from 3 to 2 are fairly unproblematic, but I occasionally get a skip from 2 to 1. I’ve been attributing it more to the size of the cog rather than the narrow wide profile, but I could be wrong on that.

    I think the reason for the n/w profile is to reduce chain drops while backpedaling, and at least in my experience, it works. With the 11 speed cassettes, in 1st gear I generally couldn’t backpedal more than 1/2 a rotation without dropping the chain. With the Eagle cassettes, I can backpedal indefinitely, even though the chainline is effectively worse.

    But yeah, I think it’s a trade off. Backpedaling isn’t an issue, but the shifting is a little fussier. And I’d imagine that shifting in bumpy terrain where the chain is flopping around might exacerbate the problem, since there’s a better chance that the chain wouldn’t mesh in nicely with the narrow wide teeth.

    • Blister Member
      Tom August 14, 2017 Reply

      Thanks for the quick reply, Noah. I’ve got about seven hours on the drivetrain now, and it has gotten a bit better. Honestly, I really question SRAM’s decision to address the back pedaling issue at the expense of regular shifting. Backwards priorities, IMO.

      So a couple of things worth passing on:

      1. Shifting today was better, perhaps because I followed a recommendation to thoroughly remove all the factory “lube” from the chain. Chain is noticeably more limber now.

      2. It is clear to me and my LBS head mechanic that I got an Eagle XX1 derailleur with a nearly non-functioning clutch. About as much tension as an old clutchless XTR RD.

      I’ll see the SRAM rep and discuss this later this week (he lives here in Hood River), so stay tuned, and thanks again.

      • Noah Bodman Author
        Noah Bodman August 15, 2017 Reply

        Hey Tom,

        That’s some good info. The only thing I’d add is that I’ve found that the b-screw adjustment is pretty crucial to getting good shifting (which wasn’t really the case on the 11 speed stuff), so make sure that’s dialed if you’re having shifting issues.

        But as much as anything, I think it just comes down to a narrower chain and narrower spaces between cogs. That just means the margin for error is that much smaller, so the shift cable tension needs to be that much more precise. And if it’s even a tiny bit off, that’s usually going to manifest itself as an imperfect shift at one end of the shift range. Even something as simple as having the cable clamped in the derailleur slightly wrong can make a big enough difference to throw your shifting off. And I don’t mean to imply that your mechanic is screwing any of that up – just things to double and triple check.

        I’m certainly a fan of the range that Eagle affords, and so far my shifting has been pretty decent, but as things wear out and the system gets a bit sloppier, I foresee those narrow tolerances becoming more of a liability. I’m interested to hear if you continue to run into issues.

  7. Marin February 10, 2018 Reply

    Regarding the bent cage on the derailleur.
    I have XX1 on my bike and it sucked in a stick/rough grass at one trail that caused pedal jam.
    My bike also tipped over and fell once or twice that I’m not proud of :)
    But there was no damage to the derailleur cage. It could be that the cage on XX1 is carbon and GX is aluminum. Carbon will return to form while aluminium will bend.

    I’m also bit weary of a massive (and expensive) derailleur sticking out but in over 1200km I didn’t have issues.

    While I was waiting for the shifter to arrive to my LBS, I used GX shifter and can’t fault it. Difference between the two is minimal and if you don’t absolutely have to have adjustable lever it’s good idea to go with the GX shifter.

    XX1 cassette and chain are fantastic on the other hand. While they are structurally the same as X01, they have that gold hard wearing titanium nitride coating that’s holding up really well.

    I don’t get why SRAM uses black coating that wears out quickly for X01/GX.

  8. non February 16, 2018 Reply

    im surprised how durable eagle is. ive the xx1 version and 1.5year later i havent even changed the chain.. on my road bike i changed the force 22 chain about 6 times.. and the cassette 2 times.. and i dont think i ride it 6 times more.

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