Last week in a somewhat tongue-in-cheek video posted to its YouTube channel, SRAM eulogized the front derailleur, saying that its usefulness in mountain biking had come to an end. Today, we find out why, as the Chicago-based component maker unveiled SRAM Eagle, a 1x12 drivetrain system that boasts a sprawling 500% gear range thanks to a 10-50t cassette. That's roughly the same range you'd get from a standard 2x set-up, but with one less derailleur and a cleaner cockpit.

For now, the new set-up will be available at the XX1 ($1417) and X01 ($1193) levels only, though we expect to see mid- and lower-tier options sometime down the road. Claimed groupset weights are 1456 grams and 1502 grams respectively, not including the bottom bracket. Availability is set for June. And old school riders will rejoice at the inclusion of a Grip Shift option.

You can see claimed individual part weights, colors options (including gold), and more in two the charts below. Click on the image to enlarge.
SRAM Eagle XX1
SRAM Eagle X01

SRAM, which deserves much credit for harkening in the age of single-ring MTB (and cyclocross and road) set-ups, says Eagle is its "most advanced and highest-performing drivetrain to date… These drivetrains have not only been refined, we have torn them apart, built them up, tested, tweaked, engineered and tested again."

Here's another video from SRAM explaining why they're convinced 1x12 is the way of the future. Scroll down for a full part-by-part breakdown starting with the all important chain.

The marquee-topping SRAM XX1 Eagle is billed as a cross-country-optimized drivetrain that combines new 1x technology with lightweight materials. Indeed, SRAM claims the XX1 Eagle group weighs up to 300 grams less than 2x drivetrains with similar gear range. Meanwhile, the X01 Eagle is targeted at the trail/enduro crowd, presumably providing greater durability. Claimed weight savings between SRAM Eagle X01 and 2x drivetrains with similar gear range is 250 grams.

Eagle Chain in Gold

Eagle Chain

Calling it the biggest contributor to the "Eagle drivetrain's ultra-smooth, precise, durable and quiet performance," the new chain's links have a smooth radius, with no sharp edges or chamfers. This, says SRAM, yields a reduction in noise, friction and wear on chainrings and cassette cogs.

The design also allows for a flatter plate, meaning more consistent chain riveting for improved strength. Further, SRAM's "hard chrome" technology is claimed to extend performance life, and a titanium nitride coating on the gold and black models is said to decrease corrosion and further reduce friction. (Yes, there are color options, including silver, too.) The chain is closed via a familiar PowerLock, and is only compatible with the new Eagle 10-50t cassettes. It comes in XX1 and X01 levels.

SRAM Eagle X01 Cassette

Eagle Cassette

Designed for use with an XD driver body, this 12-speed, 10-50t cassette offers a 500-percent gear range at a lower weight than 2x systems, says SRAM. They also claim the X-Dome architecture is among the strongest on the market, and that new shifting characteristics improve both, inboard and outboard shifting, as well as chain retention. The cassette is built with a machined cromoly 11-cog cluster, plus an aluminum 50t cog. It comes in XX1 and X01 levels. Gear steps are: 10, 12, 14, 16, 18, 21, 24, 28, 32, 36, 42, 50. And unlike the recently released OneUp 10-50t set-up, the Eagle cassette does not require the less-common mini-driver to utilize the 10t cog. Instead, if your bike is compatible with SRAM 1x11 it should work with 1x12 as well.

Continue to page 2 for more on the new SRAM Eagle group »

SRAM Eagle XX1 Drivetrain in Gold

XX1 and X01 Eagle Crankset

The new XX1 carbon crank is claimed to be a completely re-engineered design. That includes a hollow internal architecture, combined with a proprietary "carbon tuned" lay-up that allows for construction of a lightweight, efficient crankset best suited for cross country riding and racing. Crankarm lengths are 170mm and 175mm. Bottom bracket compatibility is BB30, PF30-68-73mm, GXP, and PFGXP 68-73mm.

One step down is the X01 crankset, which has the same carbon tuned lay-up, but is built to be more durable for the trail and enduro crowd. Instead of hollow, arm material is carbon composite with a foam core. Available arm lengths are the same 170mm and 175mm with the same BB compatibility.

SRAM Eagle X01 Crank in Black

Eagle Chainring

The new X-Sync 2 chainrings are claimed to deliver quieter performance than their predecessor, with better mud clearance and durability. Tooth counts are 30t, 32t, 34t, 36t, and 38t. A longer, positive-rake tooth shape is specifically designed to work with the new Eagle chain to increase chain retention and overall pedaling efficiency, while decreasing friction, noise, and wear. Rings are made from forged and machined aluminum with an anodized finish. Attachment is direct mount.

SRAM Eagle XX1 Rear Derailleur in Gold

XX1 and X01 Eagle Rear Derailleur

In order to meet the greater capacity needs of the 12-cog system, the new derailleur has a larger, 14-tooth X-Sync lower pulley (as opposed to 12 before). The X-Horizon 'straight parallelogram' design is claimed to limit all movement to the horizontal axis, which makes ghost shifting rare while also reducing shift force. It also has a new Type-3 Roller Bearing Clutch that's claimed to feature a smoother torque curve for a quieter, more consistent operation and feel. Cage lock has been moved back and out of the way, protecting it from trail debris, and the mounting system has been redesigned for better performance and overall durability. The XX1 derailleur is made from forged aluminum and has a carbon cage with lightweight hardware. The spring is titanium and bearings are stainless steel. The X01 Eagle rear derailleur has the same functional features, but a full aluminum cage.

SRAM Eagle X01 Trigger Shifter

XX1 and X01 Eagle Trigger Shifter

Internals have been updated to include a 12th gear, and SRAM says it's improved trigger feel, precision, and durability. On XX1 a carbon trigger and cover reduce weight. Customization is done via the adjustable pull-lever and MatchMaker X. Finish is anodized aluminum and bolts are titanium. The X01 Eagle trigger shifter has the same functional features but is all aluminum.

SRAM Eagle XX1 Grip Shift in Gold

XX1 and X01 Eagle Grip Shift

Not a fan of trigger shifters. Rejoice at the inclusion of Grip Shift, a concept that helped get SRAM off the ground 30 years ago. The new XX1 Eagle Grip Shift follows in the same tradition of making shifting easier, but includes more robust internals that make it more durable and shifting performance more precise. Weight is reduced via a carbon fiber cover. The X01 version forgoes the carbon cover.

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