Welcome to the SRAM School of the Mountain, the Whistler-based home of the all-new XX1 drivetrain. It's time to get your learn on.
The XX1 derailleur has deep roots, using "Straight-P" technology that stems clear back to old 6 and 7 speed road bikes. Several years later, the enduro scene will be the first to benefit from its resurgence. Could downhill be next? We're guessing so.
The X-Horizon rear derailleur, from prototype to finished product. This thing is exciting. Note that it can't be used on 2 or 3X systems as it doesn't have the necessary chain growth capacity.
Here's your typical parallelogram style rear derailleur. Note the 7mm offset distance between the center of the pulley and the point at which the cage pivots.
"The secret" of the X-Horizon derailleur lies not only in the horizontal plane on which it moves, but also in the increased offset distance of 44mm. As the cage rotates, this ensures that the pulley stays close to the gears for fast and precise shifts.
Here it is in action. See how the cage swings down, not the body? For those wondering about clearance, the cage length is equivalent to an XO medium cage.
Jerome Clementz has spent the longest time on XX1, rallying enduro courses around the world and winning one at Crankworx. He'll run a chainguide for the roughest of courses, but spends the majority of his time without one. Seriously. No guide.
What about that little 11-speed chain? Surely it's weaker, right? SRAM says that isn't the case because it sees less side-to-side bending. We'll have to verify that one later on.
Another key to the system is the CNC-machined chainring. Each tooth’s thickness is precisely CNC-machined to support the chain’s inner and outer links. The rear derailleur pulleys share this design. We dig the fact that all sizes of chainrings fit a universal spider, allowing you to swap them without removing the cranks.
Also, we know you're curious... Yes, the chainring is compatible with current 10-speed systems, but the use of the entire XX1 system is required to see the full benefits.
The XX1 cassette starts at 10 teeth and climbs to a whopping 42. Why not 9 at the low end? Due to chain drag (bending), less engagement, and increased skipping on 9 teeth, SRAM decided it best to stay with 10.
The cassette doesn't mount using a lock-ring at the end of the hub like traditional designs. There simply isn't room with a 10 tooth cog. Instead, the XD driver body hooks on from the inside.
SRAM has made it possible for any hub company to manufacture the XD driver body, so expect to see more hub options in the near future. It takes just five minutes to swap a traditional body out for this new one.
To test the XX1 system out, we headed to the Top of the World with Curtis Keene, enduro racer extraordinaire. This new drivetrain is right up his alley.
If there's one thing Keene appreciates the most, it's the similarity to tried and true 1x10 but with a larger range.
Things we loved: Without a guide, there's no resistance and no noise when you pedal. Shifting performance was easily the best we've experienced, and it never skipped during our ride. Add to that the massive range of gears and well... awesome.
You know the silence you get while riding chainless? It's the same with XX1, except now you're able to sprint to keep up with guys like Keene.
Video or it didn't happen, right? XX1 is silent and solid, even over rough terrain. We never dropped a chain, and neither did anyone else.
Our first ride was eye-opening. XX1 is simplicity at its best, and frame manufactures believe in it too. Expect to see a few new bikes at Eurobike without front derailleur provisions.
XX1 is coming this winter. You can bet that it'll be on our Christmas wish list. Visit www.sram.com for more details.