SRAM XX1 Drivetrain

Specs: 2013 SRAM XX1 Group (shifter, derailleur, crankset, cassette, chain)

Bike Setup: Black Market Roam, 160mm Travel, Enve AM wheelset, Saint 203mm Brakes

Days Tested: 30 rides, 60+ hours

Test Locations: Pedal and shuttle-access trails, Salt Lake metro area, Utah.

Black Market Roam with XX1 Build Kit
Black Market Roam with XX1 Build Kit

The new SRAM XX1 group is, I believe, the first complete group specifically designed from the ground up for single front ring use on a mountain bike. Previous single-ring groups such as SRAM XO DH and Shimano Saint incorporated road cassettes and short derailleur cage lengths, rather than being purpose built for the application.

While some components in the XX1 group (e.g., the shifter, crank-arms, and chain) are incremental updates to the existing SRAM XX 10 speed group, several key components have been designed specifically for the purpose of single-ring use. The cassette features a far larger range (10-42 vs. 11-36) in its gearing, and it affixes to the hub in a new manner to accommodate the 10t cog. The derailleur moves in a linear manner rather than diagonally, as previous rear derailleurs have. And the chainring uses an alternating wide-narrow tooth design to better retain the chain.

Why Go 1 x 11?

The biggest selling point of the XX1 group, and its push into 11-speed territory, is to offer an adequate gear range in the single-ring format for most users.

I don’t think anyone who rides bikes a lot particularly likes front derailleurs—they are noisy, they rapidly lose their shifting precision as the chainrings wear, and they frequently drop the chain when riding through rough sections of trail. The additional gear range that a front derailleur provides on trail bikes is really the only reason to run multiple chain rings.

Long story short, modern 5-6” bikes have become so light and capable that a better option became obvious: marry wide-range rear cassettes to single front rings. The result is better chain retention at speed through rough terrain, a quieter ride, and less maintenance. And the explosion of popularity over the past two seasons with folks running single-ring setups paired to 11-36t / 10-speed cassette illustrates the demand for this simplicity.

However, many users of 10-speed single rings have longed for a bit more range, finding that the 11-36 cassette range either sacrifices a bit going up (“I wish I had just one more shift”), or sacrifices a bit going down, especially on a long paved road exit to the car. And on many rides, the longing is for one more shift while climbing, and one to two more shifts while descending.

Sram XX1 Gearing Overview

The XX1 can be set up using any one of six big rings, ranging in even multiples from 28t to 38t. So a quick breakdown on how the gearing of the XX1 works relative to a few conventional setups is a good place to start. For the sake of this review, those will be:

• a conventional 9-speed, 24-32-44 front / 11-32t cassette
• a 22-32-44 front / 11-34t cassette micro triple gear range, and
• a 10-speed, single 32t front / 11-36t cassette arrangement.

With a triple crank, you generally would use:

a) the 2-3 largest cassette cogs with the granny ring
b) the 2-3 smallest cassette cogs with the big front ring
c) the entire cassette with the middle ring, since all the other gearing options overlap and are superfluous.

With a single-ring setup, you use every single gear in the range, and don’t have to lug around overlap material.

With that in mind, the easiest way to compare drivetrains is to look at their highest and lowest available gearing. And for the sake of simplicity, the descriptions of the gear ratios that follow are defined as such: if a gear is less than 1.5% different, I will refer to it as being “equivalent.” Jumps in shifting on most clusters are on the order of 5%, and that is what I refer to as “one shift.”

Sram XX1 Relative to Triple Setups

Low End:

The XX1 with a stock 32t chainring (the middle of the six available sizes) and the 42t big cog in the rear yields a gear ratio similar to a 24t chainring (granny ring) and a 32t cassette cog on a 9-speed setup. The XX1 is just one shift short of a micro-triple gearing—22t chainring and 34t cassette—of the widest triple range out there.

High End:

The same XX1 32t chainring mated to the 10t small cog yields a gear ratio equivalent to the 44t chainring paired to a 13t cog – 2 clicks up from the tallest 11t cog on the cassette.

This XX1 arrangement therefore offers the same range of a conventional triple crank setup, minus a total of two shifts from a traditional triple gearing and three shifts compared to a micro setup.

By changing the front chainring, you could set up the XX1 to give up the micro’s low-end hill-climbing ability (relative to the 22t chainring / 34t cog setup) by going to the smallest 28t chainring. Doing so would cost you three shifts on the top end.

XX1 Relative to a 10-speed Single Ring

The XX1’s 10-42 cassette is obviously going to offer a wider range than a 10-speed 11-36 cassette, but the questions are (#1) “How much wider?” and (#2) “Which gearing (i.e. chainring) should I select?”

High End:

• The 32t chainring mated to the XX1’s largest 42t cog is the equivalent of two shifts lower/easier than a 32t chainring mated to a 10-speed’s largest 36t cassette cog.

• The 34t XX1 chainring mated to the 42t cog is the equivalent of being one shift lower/easier than the 10-speed’s 36t cog.

• The 36t XX1 chainring mated to the 42t cog is about the same (a half shift lower/easier) than a 32t / 36 cog arrangement.

Low End:

• The XX1 32t / 10t cog arrangement is one gear higher/harder of a gear than a 32t / 11t cog pairing.

• The XX1 34t / 10t cog is about 1.5 shifts higher/harder.

• The XX1 36t / 10t cog is two shifts higher/harder.

So, What Size Ring – 32, 34, or 36?

So if you are currently running a 10-speed single-ring setup and wish to go to an 11-speed for an increased range, figuring out the gear range you want is really pretty straightforward. If you are coming off a fairly standard 32t front ring, then the questions are:

a) Do you want to keep the same gearing when climbing, but add a higher end for going downhill? Go with 36t.

b) Do you want one shift more while climbing and one more shift while descending? Go with 34t.

c) Do you simply want more help on climbs, and don’t need a bigger gear for going down? You can add two more shifts for climbing by going with 32t.

What I Chose

I have ridden a 10-speed, 32t / 11-36 setup exclusively for the last two seasons, and while there were a number of climbs where I would have loved to have one more shift, I didn’t really ever need it … but I did have to force my way through a chunk of hill on a number of climbs, grinding it out to the top.

On the XX1, I have experimented with various chainrings, but have settled on the 34t, though I will occasionally switch to a 36t if I’m going on a ride that has a long road section back to the car.

Sram XX1, Blister Gear Review
Marshal, Glenwild Loop, Utah.

The 32t was really nice to have on my XX1 at the start of the season, but with mid-season fitness coming on, I don’t really feel the need for the easier gearing, and I really appreciate the top speed. But having the one additional bail-out gear with the 34t / 42t ratio is still much appreciated from time to time.

NEXT: A Look at Each Individual Component

16 comments on “SRAM XX1 Drivetrain”

  1. nice review professor-

    how about a 500 word essay on that roam? thing has been catching my eye more than kate upton doin’ the harlem shake…..

    • hey man, have to say that i am really happy with the roam thus far. it, at the very least, is a very solid trail bike. goes, stops, jumps. does all that jazz very well. the DH park is just opening up this weekend, so once i can put a bunch of laps on it there i will be prepping a real review, but super happy with it thus far.

  2. off topic again- but gear geaky all the same

    how would you consider it rating as a smaller sibling to a park bike? -or in other words as a dh’rs 30 ish lb do everything trailbike? does it compare to a spitfire or knolly endo for trailability?

    • hey mb-

      you are describing me, indeed. my build is about 32lbs right now with the ROAM, but that includes a 66 evo fork and 8″ saint breaks, so figure about 30 with a lyrik and 6″ xtr trails.

      the frame is every bit as stiff laterally as my old TR250, and significantly more stiff than a stump jumper or some trail bike. it descends corners more like a park bike / free ride bike than an xc bike. I would think its pretty similar to a knolly chilcotin in that regard. I would say the ROAM pedals better and is way more fun descending than the OG endorphin. i have not ridden a new endorphin though, but i attribute that to the high-ish single pivot that the ROAM utilizes. the wheelpath is fairly rearward due to the pivot location, so the wheel does not hang up, but the chain line is straight thru the pivot, so it pedals very well.

      there just isn’t much in SLC to justify a full blast DH bike unless you are looking to drive a couple hours, but there is plenty of rough high speed riding that a 160mm bike feels at home in. the ROAM is perfect for this.

      hope that helps?

  3. Great write up. Thinking my new ride may be 1 x 11. I have dabbled with 2 x10 on my wife’s bike but have been 3 x 9 for years. How big a deal is the transition from the 10 tooth across the cassette to 42, thinking the transition from hi speed through a depression (stream or what not) to steep up? Filling out order form, XT 3 x 10 or XO 1 x 11, expecting I’ll be real happy regardless.

    • hey jim,

      it takes 3 pushes of the thumb while soft pedaling to get from a tall descending gear to a hill climbing gear. with a 3x setup, you would need to shift down 2 clicks in the front ring, and probably 2 or more thumb pushes to the rear derailleur to get to a hill climbing gear… so yeah, i would take the 1x setup all day long here.

      hope that helps?

  4. Marshal, really great review of this thanks so much. best info out there on the XX1. I’ll order one to replace my 1×10 on cross country hardtail [21lbs]. I was cracking on the long steep climbs and race situations and had resigned myself to 2×10.

    • nice nigel,

      I feel fairly confident that you would be quite happy with the range that the XX1 (and pending X01) groups offer. also of note that while the XX1 crank and ring are exceptional, they are not required, per se, and you can easily run the setup with your existing 1x setup without issue.

      thanks and all the best!

  5. Funny that all the comments here seem to reveal that we were all led by the frame :)

    I’ll add another – still planning a review of that Roam? Now that you’ve had more time on it and hopefully logged several thousand feet at the Park as well as trail time, I’m curious how you’re liking it and how it compares for trail/park.

    I’m currently on a Mojo HD, which works well, but 1) feels over built for a lot of trail riding 2) does a horrible job at small bump compliance – especially at the DH park, 3) can’t convert to 275 without losing travel, 4) but is a dream to jump and pedal. Not quite burley, but not quite racy. Considering the Roam as a better option for the burly trails and all day at the park where I rarely need a real DH bike (I ride CO mostly)

  6. I’m riding a new bike with XX1 and have a few days in with a 32t up front. In Fernie BC the rides are most often grinds to the top, preferably technical followed by a technical downhill. Maybe its just my 43 years but generally I find if my eyes are tearing I don’t need to shift to a small cog and accellerate. That being said I spend most of my time in the bigger cogs on the casette on the up and just use the smaller ones for that momentum boost on the dowhill to keep the pump. So now the point. I’m considering going down to a 28t up front not because I lack the legs but more so to keep the chain in the center of the casette for more of its use. Since I never use the bottom two cogs now this move would drop one “shift” and I’ll probably climb more in the 36t cog and use the 42t as a bail out. I am concerned even with a new bike about the extreme angles chain makes and the resulting wear on the ring, chain, and casette, both of which are pricey. Any comments on the durability over time and which cogs are the ones that give up? I’m betting its the 42t.

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