SRAM X1 Drivetrain, Part 1

Noah Bodman reviews the SRAM X1, Blister Gear Review.

SRAM X1 Drivetrain, Part 1

Specs: 2014 SRAM X1 Group
(shifter, derailleur, crankset, cassette, chain)

Mounted to: Canfield Yelli Screamy (29er)

Total Measured Weight of Groupset: 1,733 grams

Intended Use: wide ranging, single-ring riding


  • 10-42 XG-1180 Mini Cluster Cassette
  • 11 Speed X-HORIZON Rear Derailleur
  • 1400 Hollow Forged X-SYNC Crankset
  • XD Driver Body
  • 30, 32, 34, 36 or 38 tooth X-SYNC Chain Rings
  • PC-X1 chain
  • 11 Speed Trigger Shifter

Duration of Test: 35 days

Locations: In and around Whitefish, MT

Reviewer: 5’9” 150lbs

MSRP: $970

SRAM’s XX1 11-speed drivetrain system has been around for a couple years, and SRAM now makes the XO1, an extremely similar, slightly less expensive group that is being put on complete, more affordable bikes than those bikes built with the top-end XX1. But the XO1 is still a fairly expensive drivetrain found on fairly expensive bikes.

With the introduction of the X1 group, SRAM is making a second push at that cost barrier, with another 11-speed, single-ring drivetrain meant to be more attainable to those that don’t bathe in fur-lined vaults filled with gold coins (or whatever the fabulously wealthy bathe in).

This review of the X1 is split into two parts: Part 1 (which you’re reading right now) orients the X1 in the broader scheme of drivetrains in terms of it’s weight and price, and compares it to 10-speed options. Part 2 discusses how the X1 system performs on the trail.

Gearing & Gear Inch Ratios

When it comes to gearing, the pros and cons of 11-speed, single-ring systems have been discussed at length by countless representatives from the kingdom of bike nerdery. But for those that haven’t paid much attention to it, here’s the gist in a very small nutshell: switching to an 11-speed drivetrain sacrifices a bit of the range that you’ll have on a standard 2×10 setup, but it’s almost the same.

The different gears on a bike can be measured a few different ways, but the most common (at least in the U.S.) is with a value called “gear inches” or “gear inch ratio.” This number is calculated using the diameter of the wheel on your bike, the number of teeth on a front chainring, and the number on a given cassette cog.

Gear inch ratio = (diameter of drive wheel x number of teeth on the front sprocket) ÷ number of teeth on the rear sprocket)

Easier gears have lower gear inch ratios, and harder gears, those that require more force to crank over, have higher ones. (If you’re interested in a more lengthy discussion on this topic, see Sheldon Brown’s Bicycle Glossary.)

With this in mind, let’s compare the ratios found on the 11-speed X1 to those on a 10-speed setup (assuming we’re running them on a bike with 29” wheels). A fairly common chainring configuration on a 2×10 setup uses a 24-tooth small chainring and a 36-tooth large chainring, and a common 10-speed cassette might have an 11-tooth small cog and a 36-tooth large cog. The gear inch ratios on this setup range, then, from 19.3 inches [ (29 x 24) ÷ 36 ] in the easiest gear, up to 94.7 inches in the hardest gear. That means the total gear “range” is 75.4 inches.

Noah Bodman reviews the SRAM X1, Blister Gear Review.
Noah Bodman on the SRAM X1, Spencer Mountain, Whitefish, MT.

Comparing this to an 11-speed setup with a single 32 tooth chainring and a 10-42 cassette (which is the gearing that I rode with the X1 kit), the gear inch ratio ranges from 22 inches in the easiest gear to 92.6 inches in the hardest, yielding a total range of 70.6 inches.

While those numbers might seem somewhat abstract, this ought to demonstrate how close an 11-speed setup can be compared to a more traditional 2×10 system in terms of gearing. With a 32-tooth chainring, the easiest gear on the 11-speed is a bit harder than that of the 2×10—to get down to that super easy 19.3 ratio with an 11-speed setup, you’d need to move to a 28-tooth chainring (which isn’t an option on the X1 cranks, but it is an option on the XX1 cranks)

However, the more important number here is the gear range; our normal 2×10 setup covers a range of 75.4 inches, while the 11-speed X1 setup covers 70.6 inches. That’s pretty dang close. And if your particular riding style needs easier or harder gearing, that range can be shifted down (made easier) by running a smaller chainring, or shifted up (harder) with a larger chainring.

For reference, the 32×42 easy gear (22 inches) that I’m running with the X1 is roughly equivalent to the easiest 24×32 gear on a 2×10 (19.3 inches). So on many 2×10 setups, that 22-inch gear would be the second easiest gear. In other words, if you’re running a 10-speed setup and you can live without your easiest gear and your hardest gear, an 11 speed setup will still cover everything in between.

Ok, that’s not quite true. With many of the 10-speed setups, cogs in the high gears are usually different in size by two teeth (i.e. the cassette progresses from a 12 tooth cog, to a 14, to a 16, etc.), and the gaps increase to 3 or 4 teeth in the lower, easier gears. 11 speed cassettes generally follow this same pattern at the high end (starting with a 10 tooth cog, then a 12, 14, 16, etc.). However, the gaps are larger in the easier gears on an 11 speed cassette; there is a 6 tooth difference between the last two cogs, which have 36 and 42 teeth respectively. So, if we’re splitting hairs, an 11 speed cassette doesn’t provide exactly the same gearing sequence throughout its range.

Noah Bodman reviews the SRAM X1, Blister Gear Review.
Noah Bodman on the SRAM X1, Tally Lake Overlook Trail, Whitefish, MT.

For people that prefer to sit and spin, this is potentially problematic. It can be a bit tougher to find that perfect gear to match your cadence when you only have one gear option in the front, and there are larger jumps between gears in the rear. Personally, this doesn’t really bother me at all. Most of my rides don’t involve long periods of spinning the pedals at a consistent cadence, and if they do, I don’t mind settling with a slightly harder / easier gear for a bit.

16 comments on “SRAM X1 Drivetrain, Part 1”

  1. Noah, your X1 vs The Field breezes over a pretty significant point. It’s still really, really expensive to buy an X1 kit since. Once you adapt your hub you’re looking at the same price as an XT kit that comes with brakes, and that’s before deal shopping. To the casual observer it appears there was very little cost savings by going to a partially milled cassette.

    Why not compare the weight and performance with what you get with a One Up kit? Since SRAM still wants a grand for the full kit this is a much more realistic ‘field’ for the real world.

    • Jeff – I definitely agree that X1 is still pretty pricey. To be fair though, I don’t think I breezed over it; I said “Even if X1 is less expensive as a kit than XX1, if you want to upgrade your 10-speed machine, you’re at the very least going to need to buy a shifter, derailleur, cassette, chain, and XD driver (assuming you have a rear hub that has an available XD driver option).
      That’s an expensive investment, especially if your current drivetrain is more or less in working order.”

      As for the One Up kit and similar offerings from other companies, I agree that those are a fantastic option if you’re looking to convert your existing bike to 1x and need a wider range than a normal 10 speed cassette offers. I’m not at all trying to detract from that as a cost effective option – while I haven’t ridden it much, I’ve played with a bike mounted up with a 40t Wolftooth replacement cog, and it seemed to work pretty well (although it definitely didn’t shift as cleanly).

      That said, my overall point is that decreasing the price of wide range, 1x drivetrains allows frame manufacturers to look at how they design their bikes differently, which I think is a good thing. But frame manufacturers aren’t going to re-design the rear end of their bike because some aftermarket company makes a replacement cog for a 10 speed cassette. That’s a stop-gap solution to fill a void of reasonably priced 1x options. X1 is still expensive, but like I said in the write-up, I think we’ll start seeing it on more and more “reasonably” priced bikes, and in not too long, it’ll be relatively common, thus rendering the stop-gap solutions obsolete (yes, I’m speculating – if 2 years from now this turns out to be completely wrong, feel free to come back and call me an ass).

      • My real gripe here is that a $1000 price tag keeps getting glossed over in most of the commentary on this package. How did we get to the point where this is considered either reasonable or mid level? The only part in the X1 kit that seems to carry forward the XX1’s development costs are those last 3 rings on the cassette. Everything else is just a boilerplate, SLX-esque component but runs double the price.

        I agree with you that front derailleurs are pointless and shouldn’t exist anymore on 95% of mountain bikes. Unfortunately, due to the hype on its kits SRAM is able to sell a package with fewer moving parts and a price tag where it’ll only sit on $3500+ bicycles. A game changing kit really needs to be priced for a $2500 retail bike to hit the masses. SRAM appears to be putting money in the bank and impeding redesigned mid-level frames until Shimano gives in and makes a real 1X competitor.

        • Yup – I certainly don’t disagree that $1000 is still pretty spendy. A couple thoughts on that:

          1) The two components that are really keeping the X1’s price tag elevated are the rear derailleur and the cassette; all the other parts are in line price-wise with comparable 10 speed equipment. The 11 speed derailleur and the cassette are both manufactured differently than, for example, the X9 equivalents. To some extent, those prices are probably inflated just because 11 speed is the hot new thing, but I also expect those prices will come down as SRAM gains manufacturing efficiencies through increased production.

          2) The price for you and I to buy this kit as an aftermarket option is high, but the price for bike manufacturers to purchase these parts to spec on a new bike is far lower. Take a Santa Cruz Bronson for example (admittedly not a mid-priced bike, but the comparison is still valid). An XT equipped Bronson costs about $200 less than one with X1 / XO1 (with all other parts being the same). So yes; XT is still a bit cheaper and $200 isn’t pocket change, but the jump up to 11 speed isn’t all that cost prohibitive in that situation. Another example: Kona just released some teasers for their 2015 lineup with a couple of X1 equipped bikes that are quite a bit less expensive than most of the high dollar 11 speed options that have thus far been available on the market.

  2. A third element that must be considered in the Price/Weight ratio must be reliability and/or longevity. While SRAM parts are noticeably lighter I’ve had problems in the past with shifters breaking after very little use.
    I’ll be interested to hear how long the newer SRAM 11 speed system lasts.

    • Wholeheartedly agree, and I’m interested as well. My prediction: X1 will fare slightly better than current X9 offerings.

      I’ll report back when I have more time on the group.

  3. Well, this has been a fine rewording of sales puffery. Solutions that demand the formation of problems are the standard bicycling industry practice. It’s nice to see that blister gear review is happy to tell us 1×11 is how things should be, since there can’t possibly be anyone riding bicycles who has no interest in being forced to use a system that doesn’t benefit him/her. If the sponsored riders/racers say it’s great, then it’s great. Besides, who ever has been heard or read to complain honestly about something that cost $1000 where their bicycle is concerned? At that level of expense, nobody wants to have the performance in situ contradict the performance imagined when agreeing to the $1000 expense.

    Are tough questions and ugly realities subjects that are best avoided when trying to grow a web brand?

    I don’t know a single rider who has been clamoring to see the death of the front derailleur, but to hear SRAM and blister speak on the subject, apparently the only people who intend to run a front derailleur now are luddites and other poor psychotic misanthropes who want everyone to ride bicycles with saddles made from granite, tires made from lead-filled iron, brakes made from a metal strap that abrades the rolling tire, and a very tall front wheel followed by a tiny rear wheel.

    • While you’re obviously welcome to your opinions concerning the front derailleur, there are quite a few people who are, in fact, clamoring to see its death. Several aftermarket component companies have sprung up with the sole purpose of allowing people to ditch their front derailleurs (see: OneUp Components, Wolf Tooth, among others). And there are literally hundreds of forum threads on pretty much every bike related website with people discussing getting rid of their front derailleurs and generally noting that FDs are increasingly unnecessary.

      Am I advocating that everyone run out and throw $1000 at an X1 kit right at this very moment? No, of course not – it’s an expensive investment and for lots of people, it’s probably not worth it. Take me, for example; I have X1 on my Canfield, which I was riding for this review. I also have a 2×10 setup on my Specialized Enduro, and I have no intentions of buying a 1×11 group or taking off my front derailleur on that bike.

      But when I buy my next bike, whenever that may be, I’ll probably be looking for one that comes spec’d with a 1×11 drivetrain. It gives me everything I want out of a drivetrain; it weighs less, there’s less to break, it runs more cleanly, it gives me the gear range that I want/need, and (at least for X1) it doesn’t increase the price of the bike by much, if anything. So yeah – I’m pretty comfortable with my conclusion that I want that.

      If you’re dead set on loving front derailleurs or if you’re just a Shimano apologist, I think you’re in good shape – I doubt front derailleurs are going to disappear anytime soon. And I certainly wouldn’t say your predilection towards one particular option for upper end mountain bike drivetrains renders you a luddite; just because this is the internet doesn’t mean we need to lose perspective on the fact that we’re discussing the finer details of leisure equipment. But I would suggest that 1x setups are worthwhile; they improve the bike’s functionality and allow for more leeway in frame design, both of which are a good thing.

    • Not exactly fair comments Cary. Almost all the peeps I ride with now ride a single ring setup, either 11 sp or a converted 10 sp. Enjoy your triple rings Cary.

  4. Just give me a 10-speed Shimano cassette, 11-42t with reasonable spacing, fitting on a standard driver, and I’d be pretty happy on my trail bike (but no go on the race bike). New cassette, new derailleur, about $200 street price, done.

    I find it interesting that the current dominant female enduro racer in the world 1) runs a double crankset, and 2) prefers a 29er to 650B.

    Finally, if efficiency matters at all, note that there is a large dropoff when going from a 12 to 11 cog, and it only gets much worse for a 10t. Perhaps insignificant in the face of other factors like tire drag, wind resistance, etc., but then again, maybe not!

    • Hey Tom – I’m with you; if some company would make a wide range 10 speed cassette that worked with existing 10 speed shifters, I think that’d be fantastic. The only issue would be finding a 10 speed derailleur that would do a good job at covering that range. Existing derailleur options sort of work, but it’s a stretch and shifting performance suffers a bit.

      As for what world class racers are running, I honestly don’t pay that much attention to it because 1) they’re in way better shape than I am and are way better riders than I am, so their gear choices aren’t necessarily reflective of what will work well for me, and 2) they’re riding whatever their sponsors tell them to. Moseley, for example, is sponsored by Shimano. So yeah; she’s not going to be racing on XX1.

      But your point about efficiency is spot on – anything below a 12t cog starts to get dramatically less efficient (I’ve heard unverified reports that a 10t cog loses something like 20% efficiency over a 12 or 13t). If nothing else, I suspect that if you’re spending much time in the 10t cog, your chain will wear out pretty quickly. But in my experience on the X1, anytime I’m in the 10t, I’m going really fast down a dirt road. The drivetrain might be less efficient, but I certainly don’t notice it. I’m just happy to have that high gear so I don’t spin out.

      • I really expect somebody to come out with an aftermarket, wide range, 10-speed cassette and derailleur before year’s end. I agree that the “bottom your b-screw” approach is moderately successful, at best.

        I tried Absolute Black’s replacement for the first “block” of a Shimano cassette, which consisted of 3 or 4 cogs of their own manufacture, going to a max of 40t, and it shifted poorly. Not just poorly in comparison to Shimano or SRAM, but poorly period.

  5. I fully agree 1×11 systems are the future. If any mid to high end mountain bike is selling with a 2×10 in 5 years time it will be a miracle. I tried the poor-man’s XX1 (that being a 1×10 with 40t rear) and I absolutely love it!

    I busted my rear derailleur on my 2×10 and had to replace it and of course the clutch XT is inexplicably cheaper than the non-clutch XT on Chain reaction Cycles. So I got it. Then I though, meh, for $150 i can buy a NW front ring from Raceface and a 40t ring from Oneup or Wolftooth. I got the Wolftooth because it came in blue :)

    I have to say, the 1×10 with Wolftooth is awesome!!! The front derailleur is like a VCR in the age of Internet downloads – totally useless. Shifting is just simple. One lever. Can’t screw up the shift and don’t need to plan in advance when transition to a steep up from a qick descent – just drop the lever and the gears switch quickly. It’s brilliant! I ride the North Shore/Sqamish/Whistler and steep transitions happen often here. People talk about the shifting not being smooth but I have the solution for that. DON’T get ride of your 17t ring in the back. Add the 40t and take off the 10t and just stay with the 12t as the smallest sprocket. You will have to get a new lock ring for the cassette, but luckily crappy cassettes (like for crappy Canadian Tire bikes) start with 11 or 12t, so just cruise by your local bike shop (or Mountain Equipment Co-op if in a big city) and they will be able to throw you a larger used lock ring for $2. Most riders will never notice the lack of the 10t sprocket. It just means you can’t go as fast on logging roads or pavement – meh – who cares unless you are racing on flat ground – but that’s what road bikes are for :)

    I’m surprised frankly that it took until 2013/2014 for SRAM to come up with it, and that Shimano still doesn’t have anything reasonable. Even if the Wolf and One-up rings die every season, it’s still cheaper to buy a new ring every season for 10 years than an SRAM 1×11 system.

    Supposedly One-up just redesigned the rear mech cage to accommodate the 1×10 – haven’t tried it – but Noah you should get on it. Get your Enduro on a poor-man’s XX1 and blog the crap out of it so we can try it out! Help us poor riders out and let’s get the poor-man’s XX1 going with INNOVATIVE companies like One up, Wolf and Raceface and not greedy SRAM (although big kudos to them for the idea) and super slow and stodgy Shimano, who will make something eventually then charge 2x what SRAM currently does.

  6. I was able to upgrade my x7 equipped bike to X01 (including xD driver) for less than the price of 2×10 XT using a WolfTooth direct mount chainring and my existing SRAM crankset (must have removable spider) and some creative shopping. I realize that $80 is “expensive” for a single ring, but it’s much better than the price SRAM is asking for their 1x cranksets, and it’s an easy viable option for most people looking to upgrade.

      • Well played Kai – and for those converting Shimano – Raceface has a 30T NW ring which I can attest works great. I calculated that i basically lost 1.25 gears at the low end by using a 30T front (raceface) and 42T rear (One-up or Wolf) – which is not a problem. Frankly i’m finding I’m spinning out less – so it’s another win.

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