Chainline and chain security are two of the system's highlight features.

Chainline and chain security are two of the system's highlight features (click to enlarge).​

Were it not for the disclaimer at the bottom of the press release, which states in part that SRAM "remains completely committed to 2x drivetrains," one might get the impression that the Chicago-based component maker was trying to kill off the front derailleur - on all bikes.

Already it's helped make 1x drivetrains for mountain and cyclocross steeds commonplace. Now SRAM's unveiled a collection of new parts designed to bring 1x shifting systems to road bikes, gravel bikes, fitness bikes, crit bikes, time trial bikes, triathlon bikes, urban bikes, and well, you get the idea. [See which company's are spec'ing 1x drivetrains here.]

Salsa is one of many brands that are spec'ing 1x on its bikes. Pictured is the Warbird gravel bike.

Salsa is one of many brands that are spec'ing 1x on its bikes. Pictured is the Warbird gravel bike (click to enlarge).​

"Two-by shifting has been around for a long time and has many great purposes. This is not a replacement," said SRAM road product manager JP McCarthy during a small press event last week in central California. "So why the fascination? Obviously we've seen huge success in mountain biking and cyclocross where the main story was of chain retention and cleaning up the bike. For road it's a different story. Here we're talking about simpler sequential one-handed shifting, and a super secure chain-chainring interface that really gives the bike a different, quieter feel. Yes, you are sacrificing something when you cut the number of gears in half. But what you get back is a bike that is simpler to interact with."

That's a bold statement - and one that's surely to get shouted down from many corners of the cycling world. The jokes about how SRAM ditched the front derailleur because they couldn't make one that worked are already flying around the interwebs. But before we delve into the right or wrong of 1x for road, here are the key specifics of what's new and what you need to know.

Teeth from 10 to 42.

Teeth from 10 to 42 (click to enlarge).​

Opening the Road

That catchy headline is not reference to some seasonal thoroughfare in the Rockies; that's SRAM'speak for what 1x will (could) bring to the road bike world. Their stance is that the definition of a road bike and what a road bike can do has greatly evolved. Think disc brakes, wide tires, and "road" races and rides that include extended time on unpaved roads and you get the idea.

SRAM is also a big fan of efficiency and simplicity versus excess and complexity (paging Shimano). Perhaps they've also realized the best way to combat ongoing complaints about its road group's front derailleur shifting was to get rid of the damn thing all together. (Our words, not theirs.) This leads us to SRAM's new 1x drivetrain systems, SRAM Force 1 and SRAM Rival 1. (Note that SRAM Force CX1 is now just called SRAM Force 1 and that there's no Red level yet "in part due to issues of weight." More on that in a minute.)

The thick-thin tooth profile improves chain security.

The thick-thin tooth profile improves chain security (click to enlarge).​

Like its predecessors, the heart of the new system are SRAM's X-SYNC thick-thin-teethed single chainrings, which expand from the previously available 38-46-teeth options to now include 48, 50, 52 and 54-teeth versions. These are combined with cassette options that include 11-30, 11-32 and the 11-36 that was released late last year and works with standard freehub bodies, and the brand new (and incredibly wide) 10-42, which requires an XD driver body. (Not coincidentally, SRAM subsidiary Zipp has launched three XD driver body compatible road wheels in the last month. You can learn all about that here and here.)

As a refresher, SRAM's X-SYNC technology utilizes tall square teeth edges that engage the chain earlier, and have rounded chamfer edges that help keep the chain in place. If you've not ridden them, they're worth a go. It's a quiet and secure experience.

And in case you're wondering, the 10-42 cassette gives you roughly 95 percent of the gear range you'd have were you running a traditional 2x10 drivetrain with an 11-32 cassette. In other words, you'll still be able to sprint for the town limit sign - and crawl up steep climbs. What wont be replaced are the evenly spaced gaps between gears. So if you love small jumps in cadence when switching gears, 1x may not be for you. At least not until SRAM offers other XD driver body cassette options that pair the 10-tooth cog with something smaller than a 42t. If for instance they offer a 10-32 or 10-36, you'd have smaller jumps, a sprintable gear, and plenty of range for steep climbs. [If you want to dive into how various gearing combinations compare, check out this handy on-line calculator.]

There are now three clutch style rear derailleurs, including a long cage version that can handle a 10-42 cassette.

There are now three clutch style rear derailleurs, including a long cage version that can handle a 10-42 cassette (click to enlarge).​

The Rear Derailleur is Clutch

The other key to this system is SRAM's Type 2 clutch rear derailleur (now called 2.1), which extends or shortens based on the situation in order to maintain ideal chain tension. Otherwise every time you shifted into the small cog the chain could come flopping off. SRAM calls this straight parallelogram design, which limits horizontal axis movement and makes ghost shifting nearly impossible while maintaining that constant chain gap across gears.

For the road version of this rear derailleur, SRAM added a barrel adjuster and will be offering three cage lengths, including a new long version that accommodates the 10-42 cassette. The short cage can handle up to a 28-tooth cog, with the mid-cage handling up to 36. The clutch rear derailleur also has a cage lock button, which locks the derailleur in place, making it easier to take wheels off and put them back on. Trust us when we say it's a wonderfully helpful feature.

Finally, it's worth noting that all these new 1x goodies will be offered in traditional and hydraulic disc braking packages (HydroR), and that SRAM's also launched a new 1x trigger shifter for flatbar bikes, which brings us to the why part of this equation.

Continue to page 2 to find out why SRAM thinks 1x for road makes sense »

Reigning U.S. national CX champ Jeremy Powers shows off his 1x skills. Photo by Nils Nilsen/N2Photo

Reigning U.S. national CX champ Jeremy Powers shows off his 1x skills (click to enlarge). Photo by Nils Nilsen/N2Photo​

You Need a 1x Bike Because…

The answer to the above question is highly variable, user dependent, and imminently debatable. For some applications it seems to make perfect sense. If you've ever tried to explain the finer points of cross-chaining to your grandma, the benefits of this-button-makes-it-harder-this-button-makes-it-easier shifting are readily apparent. Frankly, unless you simply demand even cadence jumps, there's really no reason why 1x systems don't make sense on fitness bikes, commuters and the like. Pair the new 10-42 cassette with the appropriate chainring for where you live and you'll never run out of gears.

Here are some arguments, as presented by SRAM, for other applications:

Gravel Road Riding: Chain retention is key on rough roads, and the idea of fewer parts on your bike is never a bad idea when you're venturing onto the road less traveled. And if your gravel roads point straight to the sky, the 42t cog will help you keep spinning, instead of walking.

Triathlon: Chain retention is not a big deal, but the simplicity of sequential shifting makes it easier for the rider. And many - if not most courses - can be covered by a smaller range of gears than what's provided by a traditional double set-up. Eliminating the front derailleur also means less cable routing issues with often complex TT bike frames. There is also the potential for aero advantages from losing the front derailleur, cable and hosing, and possibly the front derailleur mount.

Triathlon seems a natural application for 1x systems. Photo by Nils Nilsen/N2Photo

Triathlon seems a natural application for 1x systems (click to enlarge). Photo by Nils Nilsen/N2Photo​

Criteriums: Racers typically don't need the small chainring since courses are flat. Having a secure chain means a silent drivetrain with no chain slap. Bikes can be geared specifically to the course. These same ideas would apply to the rider who lives in a flat region of the country who simply doesn't need true climbing gears.

It's also worth noting that one chain length can essentially accommodate three chainring sizes (one below and one above the current chainring) and that a mildly competent mechanic can switch chainrings in about 5 minutes with a 5mm and 6mm Allen wrench. You'll just need to adjust the B gap because the upper pulley of the clutch rear derailleur will be sitting different because of the change in chairing size. You could also extend your chain by adding a second SRAM PowerLock, though SRAM is quick to point out that does not recommend multiple uses of PowerLocks.

Cyclocross: This application has already been proven out at many levels. (Read our SRAM Force CX1 review here.) But SRAM wanted to reinforce the fact and trotted out reigning U.S. national champion - and SRAM sponsored athlete - Jeremy Powers to sing the praises of 1x systems during the press launch. "Last year I used CX1 exclusively," said Powers. "I had no mechanicals, no chain drops, no chain suck, zero problems." And while you could easily discount this as shill, you can't argue with Powers' success. Dude won a ton of races last season.

Fitness bikes are sure to see 1x options.

Fitness bikes are sure to see 1x options (click to enlarge).​

Fitness Bikes: This is the catch-all category of flat bar bikes that would include grandma's aforementioned steed. Here again 1x would seem a great way to go. You get the simplicity of one handed shifting, which is far easier to teach a new-to-cycling customer.

Travel Bikes: Owners of Ritchey Breakaways and the like would certainly appreciate one less cable to deal with when packing their bike for travel. There's also less breakable parts when the baggage-handlers start playing Olympic shotput with your bike case.

Adventure Bikes: Call this the bikepacking segment, those folks that weigh down their rigs with 20 pounds of camping gear and take off into the woods via jeep roads and mellow singletrack. SRAM says this realm is where the loudest requests from bicycle product managers came, with a wider gear range (think 10-42) and less parts to break being the No. 1 and 1A desires. Of course chain retention is also key, not to mention saving a little weight.

McCarthy expects the overall system weight savings to be somewhere in the 150-170-gram range, though it could be less. "You take a shifter, chainring and front derailleur out, but the [heavier] rear derailleur gives a little back. Of course cassette choice will also impact the equation; a 10-42 is clearly a little heavier than a 11-28."

All the new parts will become available this summer starting in June. You can see a full breakdown of highlights, claimed weights and pricing below. Click the images for an enlarged view. Also be sure to click over to page 3 to read about our First Ride and First Race impressions.

All the Details

All the Details

All the Details

All the Details

Continue to page 3 to read our first ride and race impressions and see an extended photo gallery »

Our first 1x road experience was primarily off-road. Photo by Nils Nilsen/N2Photo

Our first 1x road experience was primarily off-road (click to enlarge). Photo by Nils Nilsen/N2Photo​

First Ride Impressions

Riding 1x systems is nothing new. I've ditched the front derailleur on all my mountain bikes and one of my cross bikes. And I can say in all honesty I don't miss it. Cadence jumps are not perfectly spaced, and I've occasionally wished for a little bit more gear when grunting up steep singletrack climbs. But mostly I love the simplicity of one-handed sequential shifting and the quietness that comes with a secure chain.

During the press event for the SRAM 1x launch we got the chance to put the new road gearing through its paces on a spirited mixed-surface ride in the rolling hills around San Luis Obispo, California. Gearing on my tester Specialized Diverge gravel bike was a 44-tooth chainring paired with an 11-36 cassette.

That wasn't enough gear for flat, fast sections, but it provided more than enough range to comfortably spin up numerous climbs, some of which exceeded 10 percent in spots. More importantly, the system greatly increased chain tension, quietness, and general confidence on several rowdy (for road bikes) dirt road descents. I never worried about dropping my chain, and could stay focused on avoiding the litany of rain ruts brought on by a recent downpour.

Of course this is just one admittedly niche application for road bikes. But we're big fans of the horizon-expanding movement underway in the drop-bar bike world, and thus welcome the notion of simplification. If this was our bike, we'd up the chainring to a 48, which would still be spinable up most climbs, and make it less likely we got spun out on descents. [For comparison sake, a 48-36 chainring-cog combination is essentially the equivalent of a 34-27.]

At the Boulder Roubaix, we raced this Van Dessel Full Tilt Boogie with a 48t chainring and 11-36 cassette.

At the Boulder Roubaix, we raced this Van Dessel Full Tilt Boogie with a 48t chainring and 11-36 cassette (click to enlarge).​

First Race Impressions

The Boulder Roubaix is Colorado's version of the famed race in northern France. And while we don't have many cobblestones, there are plenty of rough dirt roads in the rolling farmland north of the city. This is sight for this semi-annual test of mettle, which pits riders against an 18.7-mile circuit that's nearly 60-percent dirt.

Before even knowing about SRAM's new 1x offerings, I'd planned to do the race on a Van Dessel Full Tilt Boogie disc-brake equipped cyclocross bike with a SRAM Force CX1 drivetrain. The frame would allow for larger tires (27c Challenge Paris Roubaix). Gearing wise, I'd planned to run a 46-tooth chainring with an 11-36 cassette. My only concern was getting spun out when pushing the 46-11 on flat paved sections.

But thanks to the guys at SRAM who let me take home one of the new 48-tooth chainrings, I didn't have to find out if those worries were valid. The 48-11 combination was more than enough to stay in the group during what was a brisk 90-minute race. And while I didn't manage to hold the front during the final race-deciding mile, I never used the 48-36 combination on the series of short, punchy climbs that dotted the course.

Moral of the story: I felt like I had the perfect set-up for the race. Chain security was Fort Knox solid, chain slap was non-existent, and it was really nice not to think about front derailleur shifting when I was completely cross-eyed.

Looking ahead, it's hard not to imagine some version of 1x drivetrains someday showing up at the real Roubaix and other flat'ish pro road races. But only time will tell whether or not this translates into wider use by the public at large.

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