SRAM Eagle - Long Term Review
Secrets are hard to keep in the bike industry, especially when it comes to new groupsets from the main players SRAM and Shimano. Embargos and the signing of non-disclosure forms is commonplace but there’s always somebody who lets the information slip.
That’s exactly what happened with SRAM Eagle, as catalogue images marked ‘confidential’ started popping up on the internet at the start of 2016. While the images appeared legit, it was still hard to believe that SRAM was about to launch a 12-speed MTB drivetrain. I mean 11-speed really hadn’t been out for that long, so the leap to 12 seemed fanciful at the time—like April fool’s had come early.
As it turned out Eagle was real, along with its comically oversized 50-tooth cassette, and we’ve now had our 12-speed drivetrain on review for 10 months. Although it has been discussed in our initial look at the Eagle drivetrain, we’ll go over the basics once more, just in case you’re not up to speed on what it’s all about.
Why 12-Speed?
First up, Eagle wasn’t created in a game of one-upmanship or because SRAM felt that we really needed a 12-speed cassette. It came about because they wanted to provide the widest possible gear range with a 1X drivetrain.
Single ring drivetrains have gained popularity for a number of reasons. People like the simplicity of having one shifter and they tend run quieter, as the chain no longer has a front derailleur cage to rattle against. Removing the left-side shifter clears the way for ergonomically designed paddle-style dropper remotes and it cleans up the general appearance of the bike with fewer cables. Run a chain guide up front and you’ll gain better chain security too—handy if you like to tackle really rough terrain at speed.
Of course the main catch with going 1X is a reduced gear range when compared with a multi-ring drivetrain. With a 10-42 cassette, SRAM’s 1X11 drivetrain provides a 420% spread in its gear range. By comparison a multi-ring setup – Shimano 2X11 for example – delivers a 505% gear spread. The range offered by SRAM 1X11 will be sufficient for many but it can fall short if you ride in big mountain terrain, race in XC marathon events or just need a little extra help on steep pinched without wanting to sacrifice your top-end gearing on fire road descents.
That’s where Eagle delivers; the 10-50 tooth cassette provides a 500% gear range which matches the spread of a 2X11 drivetrain. Many are taken aback by the size of the 50 cog but after many months using the drivetrain, I can attest to the fact that you get used to it. In fact I was looking at the 42-tooth cog on a 1X11 drivetrain the other day and thought was a 36-tooth, 10-speed cassette—it just looked small.
There’s a general assumption that the 50 cog is only there to provide a crazy low climbing gear. It certainly delivers a nice bailout gear but you can also fit a larger chainring to increase your top-end gearing whilst retaining a relatively normal climbing gear. If you normally run 1X11 with a 32-tooth chainring, Eagle will allow you to fit a 36-tooth ring up front whilst still making it up the climbs comfortably. We have sustained steep climbs were I ride, so I was happy to stick with a 32 on my 29er and appreciated the easier climbing gears.
Check the chart below to get a better ideal of how the Eagle gear ratios compare with other popular drivetrain options.
All this is achieved without the need for special hub standards, additional wheel dish or any other oddities. The cassette fits to the same XD Driver body as their 11-speed cassettes and the drivetrain fits with both regular 142mm equipped bikes as well as those with newer ‘boost 148’ setups.
If you’re used to SRAM’s upper-end drivetrains, Eagle provides a familiar feel; both in the shifting and the gear ratio steps. From the 10 cog up to the 42-tooth second gear, the Eagle cassette mirrors the ratios found on a regular SRAM 11-speed cassette. Jumping from the 42 up to the 50 may sound like a big leap but percentage-wise, it’s a smaller step than what you get between the 10 and 12 cogs at the opposite end of the cassette. The triggers snap between the gears with the same light lever action and there’s an audible click that adds assurance to each shift.
Claims vs Reality
So that’s the guts of it; Eagle is a one-by drivetrain that matches the gear range of a multi-ring setup—simple. But there’s a lot more going on with this new drivetrain. SRAM has used it to phase in a range of other upgrades and refinements; a new-style clutch in the rear derailleur, lighter cranks new chain technology and updated chainrings. We couldn’t really comment durability in our earlier Eagle review but this time we feel comfortable enough to pass judgment.
Whenever an extra gear is added to the rear cassette, people assume that drivetrain longevity will be compromised. The cogs get thinner and/or more closely spaced while the chain gets narrower too. In this case the chain has gone from 5.6mm wide with 11-speed to 5.25mm with Eagle. Of course this alone doesn’t mean that its durability will be compromised and SRAM has put a lot of effort into the design. Where the pins used to protrude by 0.1mm on each side, they now sit completely flush with the outer plates—this accounts for 0.2 of the 0.35mm width difference. The rest comes from the new link profiles, which are designed to be 1X specific. SRAM also uses a special titanium nitride coating—they actually claim this is the strongest and longest lasting chain in the world.
To complement the chain, SRAM’s new Eagle chainrings feature a unique tooth profile that’s said to run quieter and last four times longer that their 11-speed counterparts. As with their other high-end drivetrains, the cassette is machined from a solid steel billet with the largest cog being alloy. The CNC machined steel cogs have always offered better durability than the pressed out cogs found on their cheaper cassettes.
Having spend a good number of years on SRAM 1X11 drivetrains, I’ve always found the chainrings to be a high-wear item while the cassettes are long-lasting—probably a good thing given the replacement cost of an XX1 cassette! After 10 months on the Eagle drivetrain, the chainring is still in good working order with none of the hook-tooth profile that you’d typically see at this point. In this time I’d expect to have replaced the chainring at least once with a regular SRAM chainring.
In our initial look at Eagle, we mentioned that the drivetrain was particularly smooth and quiet, even in muddy conditions. This remains true and despite encountering plenty of sticky trails; our Eagle drivetrain has not developed any roughness or grinding sensation under heavy pedalling loads. We haven’t treated it with kid gloves either; if anything it’s received less care and cleaning than usual. We’ve used any old lube for our post-ride clean-ups and only ever wiped the chain over with a rag—it’s never received a full clean and degrease. The chain remains relatively wear-free and our chain wear checker shows there’s still plenty of life left in our super-narrow gold chain.
Claims of improved durability from a drivetrain that crams so many cogs into such a tight space are bound to bring some scepticism. However our experience suggests that Eagle really is smoother and longer lasting than the 11-speed drivetrains.
With its new ‘Type 3’ clutch, the rear derailleur was also an improvement. When XX1 first came out, the Type 2 clutch was often set to be very tight; great for chain retention but it tended to cause a ‘knock’ that could be felt through the bike as the chain length varied with suspension movement. Later SRAM released a Type 2.1 clutch; while these didn’t have the dreaded knock, they lacked clutch force which increased chain slap and increased the chance of dropping the chain.
Now with Type 3, SRAM has struck the sweet spot. It has a higher breakaway force than Type 2.1 but the action is smooth and doesn’t transmit any noise through the drivetrain. I’ve run the Eagle group on two different bikes throughout the review period; a 160/140mm travel all-mountain bike and a 130/110mm travel 29er trail bike. I’ve not run a guide and only dropped the chain once in this time, so both the new clutch design and the updated tooth profile appear to be doing a good job.
One Screw Loose
It’s not all sunshine and roses though. The main mounting bolt is only held in place by an O-ring. While it can’t go anywhere when mounted to the bike, the bolt can fall out once the derailleur is removed. I always remove the derailleur when packing the bike for flights, and with Eagle you run the risk of losing the all-important mounting bolt in transit. I wound up removing the bolt and threading it into the frame to stop it getting lost.
While my review groupset was easy to adjust and shifted perfectly on the two bikes that I tried it on, I did encounter a shifting issues on an Eagle equipped demo bike. Occasionally the chain would ride up on top of the teeth after shifting into the 50 cog. The same bike was also prone to miss-shifting in the other gears. From this I learnt that the positioning of the derailleur is critical and the upper jockey wheel needs to sit just the right distance away from the cassette. SRAM makes a simple tool that allows you to check the derailleur position and it can be adjusted via the B-tension screw. Alignment of the derailleur hanger is also critical – even more so than with 10 or 11 speed drivetrains – so get the frame checked if the shifting plays up.
Aside from these two points, the shifting proved smooth, consistent and remained fairly impervious to cable friction. I ran the same gear cable throughout the review and the lever action remains as light and smooth as it was when new—a solid result in my books.
The Eagle XX1 cranks may be light (475g including a 32T direct mount chainring) but they held up to everything we threw at them. They’re only 40g heavier than the uber-light RaceFace Next SL cranks, so we’d probably point all-mountain or enduro style riders towards the slightly beefier Eagle X01 cranks—just to play it safe.
All the song and dance may surround the massive 12-speed gear range but that’s only part of the story. The gear range really is massive and it equals what you’ll get with a multi-ring drivetrain. That’s great if you need it but even if you don’t, Eagle is still worth considering. It incorporates a host of upgrades that make it smoother and quieter than their 11-speed drivetrains. Probably the biggest surprise for me was its longevity. Despite being narrower, the chain showed very little wear and the chainring in particular is far more durable.
The catch for most would-be Eagle riders comes with the price. It is expensive as it’s currently only offered at the top two tiers of the SRAM line-up; XX1 and X01. The biggest price hit comes with the cassette, which will set you back an eye watering $650 for XX1 and $600 for X01. The XX1 derailleur is $449 and the cranks go for $649 (although you could just update to an Eagle chainring if you already own a direct mount compatible SRAM crank). SRAM will have three different 12-speed chains on offer with prices ranging from $99 up to $140.
All pricy stuff for sure but it’s in the same ballpark as the equivalent 11-speed parts. We don’t doubt it’ll get cheaper too, and I suspect we’ll be seeing Eagle features kicking in at mid-range price points within a year or two. Does this mean the front derailleur really is dead? Well as far as SRAM is concerned it’s dead and buried and with the performance offered by 1X12, I don’t think it’ll be missed.
