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SRAMXX1 2.1 Rear Derailleur

Temporarily Out Of Stock

Item # SRM005F

Don't get too bummed. This item is on the way and will be available for purchase as soon as it rolls into the warehouse.

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Why We Like The XX1 2.1 Rear Derailleur

SRAM is one of the largest bicycle component manufacturers who are known for producing quality components and, over the last decade, the brand has pursued an aggressive approach to drivetrain innovation. The XX1 2.1 is the latest example of SRAM's innovation, and the lastest iteration of SRAM’s XX1 X-Horizon Derailleur. The design is based on a horizontal parallelogram that moves the body on a horizontal plane rather than up and down. By limiting the movement of the derailleur, ghost shifting becomes a non-issue. Additionally, there is a small offset between the upper and lower pulleys. No, they aren’t misaligned; they are designed specifically to provide a constant chain gap throughout every one of the rear gear ratios. This means smooth, consistent shifting whether you are shifting up or down. The body is fabricated from carbon fiber to maximize strength to weight. XX1 2.1's horizontal parallelogram is the same design that set XX1 2.0 apart from its competitors. Unlike a typical derailleur, the X-Horizon derailleur knuckle only moves side-to-side — not up-and-down. This limits the movement to the horizontal axis, making ghost shifting nonexistent. Looking at the derailleur pulley wheels, you'll notice the offset of the upper pulley. Unusual in design, the upper pulley provides a constant chain gap through all of the gear ratios. Through the combined efforts of the X-sync chainring, pulley wheels, and a Roller Bearing Clutch, a chain guide isn't needed with XX1. Your chain is tensioned with the derailleur and locked in place with the pulleys and chainring. Also, combining the Roller Bearing Clutch and parallelogram design means that you'll never get chain slap, so your chainstay won't look marmot-gnawed. The derailleur is also made to withstand repeated hits while you're navigating through a rock garden in order to eliminate the chance of throwing the chain. We'd be remiss if we didn't sing the praises of the XX1 2.1's Cage Lock technology. It locks in the open position, so you don't have to gorilla-fist your rear wheel out to address a mid-ride flat. Please note that the SRAM XX1 2.1 Rear Derailleur isn't compatible with a double or triple crank. In fact, it is only compatible with the XX1 shifter and cassette.

  • Carbon fiber rear derailleur that's lightweight
  • Parallelogram design for an innovative shape
  • Offset chain pulleys that provide smooth shifting
  • Compatible with the SRAM XX1 shifter and cassette

Tech Specs
Pull Typebottom pull
Cage Lengthlong
Recommended Usemountain biking
Manufacturer Warranty2 years

Claimed Weight

Claimed weights are provided by the vendor.

Have questions? Chat with a Gearhead


Actual weights are measured in-house by the Competitive Cyclist team.

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What do you think about this product?



Is this model compatible with 10-52 cassette?

>Rating: 5


I've put it through the wringer

Excellent choice. Put it through rough conditions, works amazing and really easy! Been using it for few years. Thinking on moving to eagle but this one works pretty much as the eagle!

>Rating: 5

1x Rules!

I've put it through the wringer

I'm a huge fan of 1x systems, and the XX1 RD has been flawless in my experience. I've logged (literally) thousands of miles, and have barely had to touch any that I've owned. The shifting is crisp and easy, especially if you simply take the time to rinse the dirt/dust from your bike from time to time. This is a staple on every MTB I own, though I'm pretty curious about Eagle ....

>Rating: 5

The Best

I've put it through the wringer

clean crisp shifting. Sram has proven year after year that this is the best 1x11 drivetrain available. Rarely have I ever dropped a chain (and when I say rarely I mean probably about 3 time in two years). Super lightweight. I love it. `

>Rating: 5


I've put it through the wringer

To put it simply this derailleur is clean. It shifts magically and effortlessly through every gear. The X-horizon keeps the chain gap constant across all 11 gears, providing fast, precise shifts. Paired with the XX1 shifter you will have unbelievable shifting action and never miss a gear. This derailleur has a carbon cage, 12 tooth x-sync pulley wheels, and ceramic bearings. This XX1 rear derailleur is an integral part of the SRAM 1x groupset.

Will this derailleur will work with the SRAM X1 11-speed trigger shifter?

>Rating: 5


I gave it as a gift but have feedback to share

Got this for my brother-in-law for his Niner RKT bike frame. He is a major bike enthusiast. I could try to paraphrase his review, but he knows more about bikes than I ever will. Here's what he said: SRAM’s 1to1 direct shifting rear derailleur combined with the newly redesigned grip shift is a perfect product. I love how easy SRAM makes it to be able to work on their products at home. The clutch system simply works and shifts on demand. Will be upgrading to the new mountain eTap when it comes. Please make it happen sooner than later. In the meantime, XX1 will do just fine.

>Rating: 5

Great Drive Train

I've put it through the wringer

The XX1 11 speed is the best by far 11 speed drive train on the market. This is my second Sram 11 speed setup. I tried going back to the other brand and didn't like it as much.

>Rating: 4

So Far So Good!

I've used it several times

Paired it up with the XX1 set up and so far satisfied with it. Specifically with the XX1 Trigger Shifted and very happy I did. Very smooth, quick, and effortless for the 11 in back set up. So far happy with the set up and deciding to convert.