The first thing you notice about SRAM’s new Eagle 1×12 drivetrain is that it doesn’t feel much (if at all) different from the popular 1×11 systems most of us are already used to. Assuming proper rear derailleur adjustment, shifting is rapid and precise, each push of the shift lever quickly followed by movement of the chain and a reassuring “thunk” that action has occurred. Honestly, in a blind “taste” test you’d be hard pressed to tell the difference… until you jump into that 50-tooth cog.
Indeed, while SRAM has trumpeted a host of non-gearing related improvements between its 1×11 and 1×12 drivetrains, it’s the gearing that will always draw the most attention. With the addition of that dinner-plate sized cog, you now have a full 500% range, which on the bike feels a lot like what you get from a traditional 2x system, just with one less derailleur and shift lever.
That later fact was noticeably important during our first thumb-to-shifter encounter with SRAM Eagle at a recent Scott Bikes press launch in Lenzerheide, Switzerland. While we were impressed with the new Spark and Scale XC bikes, the constant presence of Scott’s dual-lever TwinLoc system on our test bike handlebars occasionally made things feel a little crowded. But when you add a 50-tooth cog to the equation, the front derailleur becomes obsolete, which forever minimizes cockpit clutter.
Get all the tech, weights, and pricing details on the new SRAM Eagle drivetrain here.
The best way to understand the gearing benefit of Eagle depends on past experience. If you’ve spent time on a 1×11 set-up with say a 32-tooth chainring paired to the 10-42 cassette, then making the switch will net you a higher high and lower low if you opt to jump up two chairing teeth to a 34. Or if you’re happy with your current climbing gear, you can jump up four teeth to a 36, which will maintain your current uphill gear, but add some top-end for your next enduro sprint. (Currently SRAM is offering chainrings from 30- to 38-tooth, which is what XC superstar Nino Schurter has been running since making the switch to Eagle.)
Most of the Eagle spec’d Scott test bikes we rode during the four-day event in Switzerland had 32s up front, which for me meant easy spinning on the climbs, as I usually run a 30t on my 1×11 set-up back home. And while, I’m usually content on steep climbs, I have to admit it was nice to sit and spin at 70-80rpm once in a while, rather than grinding it out as is usually the case.
If you spend your time on a 2x set-up, the final shift from the 42 to the 50 will feel very familiar, as that 8-tooth jump is very close to the 10-tooth jump on a typical double chainring.
As for that big jump, it may sound like a giant (and perhaps awkward) leap, but the actual feeling of the shift is essentially no different than the rest. Just like a 1×11 10-42 cassette, the Eagle tooth count for the first 11 cogs is the same (10-12-14-16-18-21-24-28-32-36-42). What you might notice is that the spacing between cogs is slightly narrower, and the 50-tooth cog is 2mm closer to the spokes than if you were running 1×11. But don’t fret; Eagle works just fine with standard XD driver bodies, so you wont need to do a bunch of freehub swaps.