First Impressions: SRAM XX1

Riding Whistler on SRAM’s new single-ring group

Nouns and Verbs by Vernon Felton
Photos by Adrian Marcoux

"We're going to talk about XX1--the features and the benefits--and then we're going to ride the shit out of it," so said Tyler Morland, media manager at SRAM, in his opening address to the gathering of international journalists. Morland’s introduction proved on point: we rode the poop out of the new single-ring group and, on the whole, walked away mightily impressed by XX1.

Before we get too far into this post, here's a quick reminder as to the what and why of XX1.

At its heart, XX1 is a drivetrain system geared around a single chainring mated to a gargantuan, 11-speed (10×42) cassette. If you already run a "one by" system on your bike, you probably see where this is going: it's a simpler system with a much wider gear range than anything you could cobble together with existing 10-speed parts. Front derailleurs can be finicky beasts. More to the point, they give frame designers a massive headache (particularly designers who are grappling with squeezing 29er wheels and wide tires into longer travel designs). Taking the front derailleur out of the equation allows for a much wider range of frame designs.

While most riders are drawn to one-by systems because of the simplicity, XX1 has more going for it than that. When SRAM began tinkering with the idea of building a dedicated single-ring system they found a variety of unexpected benefits that just sort of came with the new package.

"When you take the front derailleur and front shifter out of the equation," explains SRAM external drivetrain product manager Chris Hilton, “you begin to eliminate all these compromises that exist in traditional drivetrains. We began making improvements that weren't initially on our radar."

Such as?

"Front derailleurs are supposed to drop chains--it's common sense, really--but that's what they do. They derail the chain from one ring to the next. That's fine and well, but in trying to make front derailleurs that shift super quick and smoothly, we also create more opportunity for chains to fall off when we don't want them to."

Why not simply install a clutch derailleur, such as Shimano's Shadow Plus or SRAM Type 2 models, on the bike and call it a day?

"The reason chains fall off has nothing to do with the rear derailleur," says Hilton. "It's because chainrings are specifically designed to make shit fall off. Putting a clutch on a rear derailleur is a way to address that, but you're still working against the chainrings' nature to dump chains. This XX1 ring holds chain on."

Chris Hilton, SRAM's external drivetrain product manager

The new XX1 chainrings sport a unique alternating "wide tooth, narrow tooth" pattern that meshes perfectly with the chain links and acts to keep the chain where you want it--on the chainring. The chainring is also fairly robust--spending all your ride time in just one chainring will obviously increase wear and tear on that ring and SRAM has responded by beefing up the ring.

"We're not saying that XX1 completely eliminates the need for a chainguide device,” says Hilton. “You have to decide on just how much chain management security you want or need. We are, however, confident that you aren't going to drop a chain today.”

Given that the day's test ride would cover much of the Crankworx Enduro course--including the new and very chunky Top of the World trail, that was saying a lot.

Even though the 11-speed XX1 chain is narrower than its 10-speed siblings, Hilton contends that it will prove more durable. SRAM has applied a new friction-reducing coating to the chain that, they contend, will reduce elongation and subsequent weakening of the chain. To that end, they’ve seen remarkable gains in overall chain durability in their testing.

"I guarantee you this chain will last way longer than a 10, 9 or 8-speed chain on a normal bike," says Hilton. "I can say that with a straight face. And yes, you'll see that new coating technology move over to other chains as well."

XX1 sports a very wide-range, 11-speed cassette: (10-12-14-16-18-21-24-28-32-36-42), to be exact. The chatter on Internet forums has been that there must then be massive, awkward gaps between gears, but SRAM has kept the jumps between most of the gears at a fairly constant 17 to 18 percent.

"When you have more than a 20 percent change between each cog," explains Hilton, "it feels weird. That's why most of our gear steps are between 17 and 18 percent. The only big step is on the extreme ends of the cassette–between the largest cog and the second-to-largest cog and in that gear you generally want a bigger jump, a bailout gear."

Why 11 speeds?

"We didn't set out to make an 11 speed group," says Hilton. "We wanted to make the best single-ring group with a wide enough range to be practical and that required an eleventh gear."

SRAM has been adamant from the get-go that XX1 is not intended to make dual chainring or triple chainring systems extinct. "XX1 doesn't remove two-by and three-by from the equation, but it does make sense for a lot of riders and we do see a lot of development in this in the future,” says Hilton. “Are you doing Leadville tomorrow? Okay, you should go with a double or triple crankset. You want that wider range for that kind of event, but most people don't need that kind of range."

Six chainring sizes to choose from gives riders the opportunity to vary the gear range on XX1

The gearing options for XX1 vary based on which of the six chainrings you opt to run. There are currently 28-30-32-34-36 and 38-tooth models. Changing your gearing is incredibly easy. One of the clever aspects of the XX1 drivetrain is that you can remove the XX1 chainring and swap it out without removing the crankset from the bottom bracket. XX1, however, has a unique crank spider, which makes the XX1 chainring and crankset a package deal. You can’t, in other words, install the XX1 chainring on someone else’s crank. While, you can use some other crankset with the XX1 cassette and rear derailleur, you're probably going to drop chains along the way.

XX1 utilizes a unique straight parallelogram derailleur, so, nope, you can’t mix and match it with existing 10-speed drivetrains. Likewise, while XX1 will fit on any existing frame, it does require a unique driver body. At this point, SRAM, DT Swiss and Mavic offer the XX1 driver body. SRAM, however, states that most wheel manufacturers will soon offer XX1 driver bodies, which will ultimately make the system compatible with most wheels.

Our first ride on XX1 was ambitious. The plan was to take the lift to the very top, ride the newly-opened Top of the World trail and then chase it with a mix of black diamond and intermediate trails that included No Joke, Too Tight and Angry Pirate. Once we rolled back into Whistler Village, we’d raise our saddles and pedal away for some XC riding on the Lost Lake trail network.

In short, we would take the components that were just raced to gold and silver-medal finishes at the London Olympics a few days ago (on 29er and 650B hardtails) and we'd bash the hell out of them on balls-out downhill trails. It would be an impressive test of SRAM’s claim that XX1 is a group with wider appeal than most riders would suspect.

The riding part of the press launch--a nice bit from Top of the World.

The first thing I noticed was how precise and quick the shifts were on my XX1-equipped Trek Slash--even when pedaling like a kook through chunder fields. The bike shifted flawlessly. I encountered a few of finicky up-shifts mid-ride, but chalked this up to cable stretch. A quarter turn of the barrel adjuster set everything right again.

Amazingly, no one in our group of eight riders experienced a single dropped chain over the course of the ride. Not one. Does this mean that you can toss out your chainguide entirely? If I lived for bike park riding, I'd still mount a guide, but for trail riding I can see running this thing naked. Riders like Jerome Clementz are killing it on the roughest enduro courses in the world and they've eschewed chainguides entirely when running XX1.

Our initial concern that we’d be hurting for some lower gears during the XC-segment of our ride proved unfounded. I resorted to that 42-tooth granny cog just once and even then, could have scaled the steep climb without the aid of the bail-out gear. My Trek Slash, for the record, was equipped with the 32-tooth chainring.

Of course, one day's riding in Whistler does not make for a complete product evaluation--not by a long, long shot--but a day of riding the Whistler bike park is no cake walk on components either. In short, we're looking forward to getting our hands on a set for long term testing, but we are also surprised by what we experienced out there in the dirt. Personally, what impressed me most about XX1 is its versatility. Cross-country racer, trail rider, gravity fiend--any of those types of rider can find something to like our very niche sport of mountain biking, that's a rare thing indeed.