SRAM X01 AND X0 TRAIL
Final Take: Niche demolishing. This simple, versatile group is perfect for novices, professional racers and everyone in between, on any type of bike.
No matter how excited we get about the next best widget, in the end it doesn't really matter what we are riding, just that we are. A massive amount of work goes into creating this gear guide, but do we actually need any of this stuff? No. I'm looking at all the white space on the page below my blinking cursor, wondering what to write, because none of it matters. In fact, you should stop reading this immediately and…run to your shop and demand they put this group on your bike right away.
And absolutely not take another pedal stroke until whatever drivetrain currently residing on your bike is melted down into the paperweight it should be.
Even SRAM, the innovative company that thought up XX1, didn't realize how popular the 11-speed single-ring drivetrain would be. Regardless of the word 'revolutionary' getting overused like crazy, it sort of is. Here's why: While everyone else was trying to figure out how to bolt more stuff to your bike, SRAM engineered bits off of it. Rather than tirelessly working to optimize front shifting they asked the question, "What if we could just get rid of it altogether?" That's the type of out-of-the-box thinking that put SRAM on the map.
X01 is nearly identical to XX1, with a few minor differences. The X01 chainring and removable spider are a bit less sculpted, some of the weight-saving machining tasks on the X-Dome 10-42 cassette have been spared, and carbon bits on the shifter and derailleur have been replaced with alloy. The result is about a $150 cost savings and negligible weight penalty.
Shifting is precise and instant, and the X-Sync chainring, with alternating narrow and wide teeth, never drops the chain. The simplicity of not having a front derailleur makes X01 incredibly user-friendly. We would recommend it to anyone who gets frustrated or confused by front shifting, at any skill level. Most of the skeptics we encounter mention gear range, worried that they don't have the fitness for a single ring. All we can say to that is don't be scared.
No group is complete without stoppers. We decided to include the four-piston X0 Trail brakes in this group. These brakes pack serious stopping power in a surprisingly small package. They aren't as maintenance-free as Shimano brakes, but they're stronger, modulate better, and have a smoother lever feel when they're working properly. Even though SRAM brakes have gotten much better over the past couple years, they still need to be bled fairly often. –RYAN PALMER
Final Take: The mechanic's measuring stick for durability against all other drivetrains.
There's a reason Shimano's XT group has remained the workhorse component group of the mountain bike world for 31 years—it works. True, it's not as sexy or lightweight as XTR, but it puts less of a hurt on your pocketbook and it possesses nearly all the same tricks. We've been beating on this variety of XT since the summer of 2011 and have walked away with some strong impressions.
Let's start with the shifting. It could become a bit mushy and indistinct with the previous generation of XT. Shimano fixed that with the advent of its Vivid Index shifting technology. XT's rear-derailleur shifts are now accompanied by a tangible and satisfying click. What's more, shifting remains remarkably consistent over time. I flogged an XT group for much of the season and adjusted it only once to account for the inevitable, initial cable stretch. That's saying a lot; I ride in the Northwest and I basically bathe my bikes in mud for nine months of the year.
Shimano's 2-Way Release trigger design allows you to shift up and down the cassette with either just your thumb—push-push—or thumb and index finger—push-pull. That's admirable, but in trying to please both camps, Shimano has placed the forward release trigger a little too close to the bar for index finger pulls and a little too far away from the thumb for easy push-push activation.
There is one area in which Shimano shifters clearly take the cake—you can run the same left-hand shifter with either a triple or double crankset—just twist the mode converter, and you're good. It's a nice bit of flexibility. That said it's also been a long while since I've wanted to run a triple crankset.
Shimano's XT crank is an impressive bit of gear. The crank's finish quality definitely exceeds that of SRAM's X9. Unfortunately, Shimano only offers two double cranks—the crazy-steep 40/28 model and the more realistic 38/26. SRAM, by contrast, offers four two-by cranks, including the very low 36/22, which is ideal for burlier, enduro/all-mountain bikes. Shimano needs to add some depth to its offerings.
I'm of two minds when it comes to XT brakes. On one hand, I don't care for the feel of them. I find the levers too short and their actual feel to be sort of dead until the final third of the stroke. What's more, the free-throw adjuster still doesn't appreciably change lever throw. I readily admit, however, that this is entirely personal. A lot of riders love the way Shimano brakes feel. I will say this: XT brakes are insanely reliable. I routinely get twice as much ride time between bleeds on XT than on just about any other non-Shimano brake out there. Living in a wet environment, I wish more brake manufacturers took a cue from Shimano and made the move to mineral oil. It's easy to work with and it doesn't suck up moisture like DOT fluid. –VERNON FELTON