Up And Away

The weight penalty of disc brakes is lessened by the single chainring set-up with no front derailleur.​

Editor's Note: This article is part of our Cyclocross Race Bike Shootout series, which also includes reviews of top competition steeds from Trek, Jamis, Specialized, and Van Dessel, as well as tests of several wheelsets and 'cross tires.

The Lowdown: SRAM Force CX1 drivetrain with HydroR disc brakes

I was skeptical at the outset of my test time aboard SRAM's Force CX1 single-ring drivetrain paired with the company's hydraulic road disc brakeset, wondering if a 1x set-up would provide a wide enough gear range for cyclocross racing, and questioning how well SRAM could overcome the problems that befell its first iteration hydraulic brakes, which were recalled due to cold weather failure issues. But those worries have been eased. While not perfect, both drivetrain and brakes have proven to deliver reliable race day performance. Indeed, SRAM's CX1 drivetrain paired with HydroR disc brakes would be my top choice for competitive 'cross racing - and could well be capably used for other applications such as gravel grinders, triathlon and even some criteriums. Check out the full review below to learn more about this dynamic modular system that's convinced me to drop the front derailleur for good. And read about what improvements SRAM may have in store for both the drivetrain and brakes on page 2.

Thick Thin

The X-SYNC chainring teeth are designed to keep the chain securely in place - and shed mud better.​

Cassette: SRAM 11-32 or 11-36Chainring: X-SYNC 38, 40, 42, 44, or 46t
Chain: SRAM PC-1170Cranks: SRAM Force CX1
Levers: SRAM Force CX1 hydraulicWeight: 1150-1348 grams
Rear derailleur: SRAM Force CX1MSRP: $874-$942
Front derailleur: Not applicableRating:
4.5 Stars
4.5 out of 5 stars
Stat Box: SRAM Force CX1 Drivetrain


  • Lower overall system weight
  • Bigger gear jumps
  • Improved chain security
  • Heavy rear derailleur
  • 1:1 shift actuation
  • Exposed shifter internals
  • Easy upgrade
  • B-limit screw adjustment finicky
  • Clutch derailleur ideal for cyclocross
  • Soft chainring bolts
  • Roller bearing clutch controls chain tension
  • Taller gearing compared to 2x systemss
  • Cage lock for faster wheel changes
  • Reduced maintenance
  • Improved hood ergonomics
  • Individual reach adjust
  • Reduced chain slap
  • Simpler operation
  • Exceptional mud clearing
  • Durability

Stopping Power

We like the extra power and modulation provided by the 160mm rotors. Now if we can just get Zipp to make us a set of tubeless ready thru-axle equipped wheels.​

Levers: SRAM Force CX1 hydraulicWeight: 902g (levers, calipers, hose, rotors)
Calipers: SRAM Force CX1 hydraulicMSRP: $851 (rotors not included)
Pistons: 18mm front/ 18mm rearRating:
4 Stars
4 out of 5 stars
Rotor: SRAM Centerline 160mm
Stat Box: SRAM Force HydroR Disc Brakes


  • Vastly improved braking compared to cantis
  • Weight
  • Allows for wider tire clearance
  • Boxy hood shape
  • Improved hood ergonomics
  • Brake bleeding complexity compared to cantis
  • Lower hand force required
  • Price compared to cantis set-ups
  • Individual reach adjust
  • Alloy caliper with stainless steel backed pads and stainless hardware
  • Fully sealed system
  • Tall hoods easier to grip
  • Easy to install and bleed

Full Review: SRAM Force CX1 drivetrain with HydroR disc brakes

Like a lot of people, I was skeptical at the outset of my test time aboard SRAM's Force CX1 single-ring drivetrain paired with the company's hydraulic road disc brakeset. As a mid-pack cat. 3 racer with a fairly low genetic-ability ceiling, I wondered if a 1x set-up would provide a wide enough gear range. As a follower of the cycling gear industry, I questioned how well SRAM could overcome the problems that befell its first iteration hydraulic road brakes, which were recalled at the beginning of last year.

Test Rig

We draped our SRAM CX1 and HydroR parts on the highly capable Van Dessel Full Tilt Boogie carbon cyclocross frame.​

Flash forward about four months, and those worries have been eased. While certainly not perfect (what is?), both the drivetrain and brakes have proven to deliver the kind of reliability and performance that heretofore had been the hallmark of SRAM's primary competitor in this space. For pure road applications, I'd still choose Shimano over SRAM when it comes to shifting and braking. I just think it works better. But for cyclocross racing, I'd flip that statement around. SRAM Force CX1 with HydroR disc brakes, in my opinion, is the top choice. And that statement holds whether you're name is Jeremy Powers or Joe Schmo.

Clutch Addition

The SRAM Force CX1 roller bearing clutch helps maintain critical chain tension.​

Security is Job No. 1

If you've raced more than a handful of 'cross races you've invariably encountered the dreaded dropped chain. It usually happens at the beginning of a race, putting you so far off the back you feel like dropping out. Or chain leaves chainring teeth sometime early in the last lap when a sure-thing top 5 turns into, I think I made the front half. Whatever the case, it sucks.

In the past, whether you were running a traditional 2x set-up or an old school 1x, your best defense against this malady was all manner of chain catchers, guides and watchers. Some worked better than others. None was a perfect solution. Enter the star of the SRAM Force CX1 show, the X-SYNC chainring. Utilizing the same thick-thin tooth pattern that's all but killed the front derailleur in the mountain bike world, SRAM has created a secure chain-chainring interface that's essentially eliminated dropped chains or the need to baby sit said chain with the aforementioned add-ons. The shape of the teeth help reduce side to side motion of the chain.

Working in concert with the X-SYNC chainring is SRAM's Force CX1 rear derailleur with its roller bearing clutch. I wont delve too deep into the technical minutiae, but it's basically the same rear mech used in SRAM's wildly popular XX1 and X01 single-ring mountain bike drivetrains. Chain tension changes based on current gear selection, as the clutch takes up or lets out chain slack, keeping tension constant.

To you and I that means chain security - and peace and quiet. Gone is the whack-whack chain slap so common when rambling over bumpy terrain during a 'cross race. It's a profound and welcome silence. So is not dropping your chain, which has happened exactly zero times during our SRAM Force CX1 test session, which included numerous races, hard-charging test rides, and some of the world's sloppiest dismounts and remounts, when our bike was bouncing around like a kid in a jumpy castle. Still no chain drops.

All You Need

For us, the 11-32 cassette combined with a 40-tooth chainring was the ideal 'cross race day set-up.​

Right Gear for the Job

But all this chain security is meaningless if your gearing is so tall you have to dismount and run every time the course tilts slightly upward. That was certainly my biggest concern. I've never been a big power guy, and figured a 1x set-up would leave me turning squares - or just running a lot.

Not so. Just like with its XX1 MTB platform, SRAM has engineered enough gear spread into the CX1 system that just about any amateur level racer can set it up with enough variance to assure that pedaling - not plodding - is primary mode of race transportation.

Up front, CX1 users can choose chainrings with 38, 40, 42, 44 and 46 teeth respectively. The more teeth the taller the gear. I started out on a 42t, but quickly slotted back to a 40t so I could spin easier. Whatever chainring you choose, it's paired with SRAM's 11-speed cassette, which initially was limited to an 11-32. That combination of the 40/32 was plenty for just about any obstacle faced on the 'cross course, and I'd advise any amateur starting out on a 1x system to begin there and adjust accordingly. If you're a spinner, fall back to the 38t. If you like grinding, the 42t chainring might be the way to go.

If you're reigning national champion Jeremy Powers, the 44t is the choice. "I ran a 42 once this year because I was feeling sick and got out-sprinted at the finish because I didn't have enough gear," Powers told RoadBikeReview. Most people don't have to worry about such things.

It's also worth noting that in December, SRAM added an 11-36 cassette to its CX1 product mix. This is more gear than most people will need for cyclocross racing, but it opens up other interesting possibilities which are addressed on page 2 of this review.

Powerful Endorsement

Reigning U.S. national cyclocross champion Jeremy Powers is a vocal advocate for SRAM's 1x drivetrain.​

Weights and Measures

Depending on how you add SRAM Force CX1 to your life, the system will either increase or decrease the weight of your bike. And this speaks to another of the group's upsides: modularity.

You can opt to swap on a full CX1 group plus hydraulic disc brakes, which will obviously be heavier than a traditional cantilever brake set-up. (Powers says his canti race bikes are about a half pound lighter than his disc steeds.)

You can also just add the X-SYNC chainring and CX1 rear derailleur to an existing 10 or 11-speed SRAM drivetrain, which would likely shed weight because you're eliminating the front derailleur and a second chainring. The X-SYNC chainrings even come with the spacers to compensate for your missing old inner ring. Or you could try something in between, say adding a set of Red HydroR levers instead of Force, and Red crankarms (both of which would be lighter, but more expensive).

Whatever the case, all the X-SYNC chainrings are 110 bcd, which allows for all this swapping as long as your starting point is an existing SRAM 10- or 11-speed drivetrain. And if you're going from a 2x to CX1, you can even strip out the internals of the left-hand shifter, since it will no longer have anything to shift.

Big and Beautiful

Though a little on the heavy side and finicky to set up, the SRAM Force CX1 rear derailleur does a solid job of moving the chain up and down the wider cassette and maintaining chain tension.​

What's Not to Like

Arguably the No. 1 thing you need to know is that by forgoing a second chainring and using a cassette with a wider gear spread, you'll encounter bigger jumps between some gears. This wasn't a huge issue during our test time, but there were certainly a few instances when the proverbial porridge was too hot or too cold but never just right. Whether it was grinding up a hill or trying to close a gap during a flat section, it sometimes felt like the gear I was in was too hard or too easy and the next one up or down was just the opposite.

But that's the nature of the game when for instance you switch from the more tightly spaced 11-28 cassette (which has cogs of 11, 12, 13, 14, 15, 16, 17, 19, 22, 25 and 28 teeth) to an 11-32 (which goes 11, 12, 13, 14, 15, 17, 19, 22, 25, 28 and 32). Depending on what you were used to before, sometimes you'll miss that 16 or 21 or 23, and there's nothing you can do about. The good news is that if you're like me, you'll soon forget about what you've given up and get used to spinning a slightly different cadence.

Another rub on SRAM CX1 is rear derailleur adjustment. It can be a little finicky, and as one pro level mechanic put it, "There always seemed to be a compromise between great shifting on the top of the cog and great shifting on the bottom, but never perfect in both."

This is tied to adjustment of the B Limit screw. SRAM recommends 1cm of clearance from the top of the pulley to the largest cog, but with an 11-32 cassette, that can cause the shifting in the lower cogs to be a little sluggish. It's not like it doesn't work, but in my experience it certainly could be a little more crisp. Edwin Bull, owner/operator of Van Dessel Bikes, which provided the full carbon Full Title Boogie cyclocross frame for this test, says he too is a big fan of SRAM Force CX1, but agreed that it can be a "little loud in the larger cogs."

We broached this subject with Nate Newton, SRAM's road technical marketing rep, and he admitted that overall he'll spend more time adjusting the rear mech of a CX1 system versus a 2x rear derailleur.

"What I've found works best is to start by making sure the derailleur hanger is dead on," Newton explained. "Then I dial out the B limit screw reasonably far because the system usually runs well with a big B gap. So I dial it out far enough that when I am going onto bigger cogs I am not going to have clearance issues with the top pulley going into those cogs. Then once I am on largest cog I dial the B gap back in until I am really getting a smooth shift off that largest cog."

Newton adds that it's also key to have set up the high limit correctly at the other end in the 11-tooth cog. "If that limit is set properly I can run reasonably low tension," he continued. "This is something that applies to just about all SRAM derailleurs. If you get the high limit set right you can run much lower cable tension than you can with competitor's groups. I think sometimes that's something people forget. So dial in the B gap so the shift off the 32 is good and that tends to clear it up all the way through the cassette range."


Our cyclocross bike has turned into our go just about anywhere bike.​

Our pro mechanic also took issue with the openness of the HydroR shifter internals. "After any really dirty or dusty race, we'd have to flush out the shifter with WD-40 to get them to work correctly. They jammed up pretty easily."

SRAM's Newton said he wasn't aware of this issue, adding, "We feel like our shifters with the way the rubber hood covers them, are more closed than our competitor's product. But super muddy cyclocross is super muddy cyclocross."

Fair point - and in our experience, which was limited to a very dry amateur 'cross racing season in Colorado, shifting performance held up admirably without much TLC beyond the occasional garden hose spray down. But if your 'cross arena is frequently drenched in muck and mud, it's something to think about.

Continue to Page 2 to read about our test impressions of SRAM's hydraulic disc road brakes and hear what SRAM may be planning for the future »

Less is More

SRAM whittled away its shift paddle, providing greater finger clearance.​

Let's Talk About Brakes

While not required to run a CX1 system, this test also included extended time on what SRAM calls its MY15 HydroR hydraulic disc road brakes, which is another way of saying these aren't the brakes that they had to recall in January of 2014.

Our first experience on SRAM's hydraulic road brakes was actually on a set of the recalled version. Fortunately we never had any issues. In fact, then as now, modulation and power was impressive. Anyone worried that disc brakes on road or cyclocross bikes are dangerous because they're too powerful simply doesn't understand how they work. The predictable leverage ratio of hydro disc brakes delivers better control and modulation with less hand effort. Whether ripping down a paved mountain descent or diving into a muddy corner in a 'cross race, hydraulic disc brakes (be them SRAM or Shimano) slow you down in a precise and controlled manner. Racers can carry more speed and brake later going into corners.

What don't work well oftentimes are cantilever brakes, which in my experience, squeal, cause fork shudder, and generally create a feeling of uncertainly as you plummet down steep inclines. Yes, I'm a passionate disc road convert even if there is, as Powers noted, a half pound weight penalty.

Our pro cyclocross mechanic took a similar stance, saying he had no complaints at all. "It's hard to believe after all the screw-ups with the first generation that these worked flawlessly for our team all season," he said. "They are easy to bleed, which we hardly ever had to do. They are easy to install and they were reliable. We didn't even run through brake pads very often. No, the lever feel still isn't as good as Shimano, but functionally, they're on par."

No arguments from this tester. All else being equal, we'd opt for the smoother feel of Shimano's R785 hydro brakes, which we rode during tests of 'cross race bikes from Specialized and Trek. But it's not a huge difference - and until Shimano makes a serious play in the 1x 'cross arena, we'd accept the slight drop in braking feel for the gains of the simple, lightweight and reliable CX1 drivetrain for pure racing applications.

Here's a look at some of the changes SRAM incorporated into the brakes following the January 2014 recall.


Hold Tight

While some balk at the height of the SRAM HydroR hood, it certainly provides more to grab onto.​

SRAM also gets props for making some nice on-the-fly improvements between the recalled brakes and this version. While still a little boxy, hood ergonomics are improved. It also trimmed the size of the shift paddle, which provides more finger clearance when braking, and is especially invaluable if you're wearing thick gloves.

What Say the Euros

Until the final race of the 2015 UCI world cyclocross championships, it was common to wonder why the top European pros had been slow to adopt disc brakes. Powers blamed it on a combination of old school mechanics and weight.

"Weight will always be an issue," the U.S. national champ admitted. "I still have a canti bike that I race in certain situations. I think in some cases it's a course thing. In the U.S. we have a lot of blazing fast courses where we need disc brakes on our bikes. But a lot of the courses in Europe are slower because it's always wet so you don't have to come off high speed as much. That's when the weight matters more. But I also think it's about the Euro mechanics not knowing the technology. It's a lot of old Belgian and Dutch guys and you just cant say you have to start bleeding these brakes and switching pads and deal with different hub widths. It will take time for whole sport to get their heads around the change."

Da Man's Machine

Jeremy Powers Focus race bike with full SRAM CX1 and HydroR.​

That change may come sooner than later. We interviewed Powers in December. In late January, two of the top 3 riders in the men's elite race were on disc equipped bikes, including new world champion Mathieu Van der Poel.

"Top level European racing always seems to be hesitant to adopt radical technologies," added SRAM's Newton. "But we are starting to see that change with some of the young pros who are on disc and winning. I'm actually surprised to see how fast adoption is happening."

What Does the Future Hold?

We're aware that cyclocross season ended a few days ago for the pros, and probably at least a month ago for most people reading this review. Thus we'd be remiss if we didn't try to look into the future and guess what improvements the next iterations of SRAM Force CX1 and HydroR might have.

Reduced weight is always the obvious starting point, and SRAM's Newton says that is certainly in the realm of possibility. "As soon as we told Jeremy Powers about the group, he wanted a Red version," said Newton. "Higher - and lower - cost 1x systems are certainly possible. And right now because of the 110bcd chainring and the same cable pull as other shifters, you can already use a Red crankarm or Red shifters if you want."

"Also the rear derailleur is obviously not the lightest we've ever made but a lot of that comes from really essential parts," added Newton of a difference that's about 100 grams more than a Red 22 derailleur. "The clutch will always add a few grams but it's a really key part of the system. Of course we are always keeping our options open."

Swap In

Powers saves weight by swapping in a Red crankarm to what is otherwise a Force level offering.​

As for improvements of the brakes, Newton points to the sport's governing body as holding the key. "We really hope that disc brakes will be UCI legal for road racing soon," he said. "Once that happens getting feedback from the pros will be key. Right now I feel like our system has great power and modulation. But overall weight remains an issue, especially for road applications. I can't tell you how we change that at this stage. But given that we've already solved a lot of important issues, and we're only two years into this, it's fair to say there are plenty of improvements that are still possible."

And while that possibility probably doesn't mean totally killing off the front derailleur like what's happening in mountain biking, SRAM Force CX1 may well have application beyond cyclocross.

"The next step is to figure out how to expand the gear range to make the group more plausible for more uses," explained Newton. "When we introduced the group in January of 2014, we didn't have the 11-36 yet. But now with that cassette option, you have a gear option that is 13 percent lower than the 11-32. That might not sound like much, but if you have a 42/36 combination you can pedal up just about anything. Or you can go up to the 46t chainring and have a 46/11 that's not too bad in a highspeed road situation. We don't see the 1x being an end all for all road use, but for crits or triathlon or some gravel races where chain security is really important, it could be the way to go."

It's certainly an appealing concept - and one we plan to put to the test. With 'cross season done, we'll swap an 11-36 cassette, 46-tooth chainring, and a set of 40mm tires onto our test rig. Then what was a dedicated CX race bike will be ready for everything from steep road climbs to gravel grinding to light duty singletrack. More fun is sure to follow - and that's what it's all about.

For more information visit www.sram.com and make sure to check out the extended photo gallery below for more details on SRAM Force CX1 and HydroR, as well as pictures of Jeremy Powers national championship winning race bike.