The not-so-minor details
SRAM XX1 groupset
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Crankset w/ BB
Simpler, quieter, lighter
Flawless shifting performance
Bottom bracket still not as good as Shimano's
After more than six months on SRAM’s 11-speed, single-ring-specific drivetrain, we’re ready to give up a kidney to get this system on all of our bikes. Hands down, this is the best mountain biking product to have been released in quite some years. Here are 11 thoughts about going 11 speed.
1. The triple chain ring is dead. Its reign ended the day 10-speed mountain bike shifting was released. With the advent of the 36-tooth rear cog, the 22-tooth chain ring became superfluous; two chain rings paired to an 11–36 cassette was all you needed. And now, with the development 11-speed XX1, we think the days of 2×10 drivetrains are numbered too.
We’ve been fans of 1×10 drivetrains for a while now, but a 1×10 setup inevitably has some compromises, particularly when it comes to climbing. You do still lose a small amount of gear range with XX1, compared to a double-ring setup, but it’s negligible. And when you consider the advantages, the compromise is well worth it.
2. The right gearing for 99 percent of the time. We have encountered precious few situations where we’ve been left wanting more gears, in either direction. On our test bike we opted to run a 34-tooth chain ring – it was the perfect choice. If you’re struggling to push a 34:42 uphill, you’re going to go just as fast if you hop off and walk. At the other end of the spectrum, a 34:10 is more than tall enough to sail along a fire road at over 40km/h.
3. This is not a cross country-specific product. One of the most impressive things about XX1 is how it can’t be pigeonholed as a product for a particular style of bike. While we’ve been running it on a cross-country race bike, it’s just as applicable for use on a 160mm-travel all-mountain bike. We’re sure that some of the XX1 technology will be adopted in the downhill world soon too.
4. We have not dropped a chain. From the very first day we installed our XX1 drivetrain on our Trek Superfly test bike, right up until the moment we sat down to type this review, we are yet to drop the chain on our XX1 groupset. And, no, we haven’t been running a chain guide. Furthermore, it hasn’t felt like we’ve come even close to losing the chain. There is so little chain slap going on, you just know that the chain is going to stay in place.
Part of the XX1’s amazing chain retention comes down to the tooth profile of its chain ring. The teeth are in two widths and they alternate (wide, narrow, wide, narrow), so they mesh perfectly with the alternating widths of the chain links. It’s an incredibly simple solution, and now we’re starting to see copycat rings from other manufacturers as well.
5. You’re never caught out. How many times have you caught yourself in the wrong chain ring, having to crunch a shift under load? Or had to listen to the grinding of an out-of-adjustment front derailleur? Or shifted to your granny ring and dropped the chain onto your bottom bracket? These issues don’t exist with XX1. You’re never caught in the wrong ring, never listening to a grindy front derailleur, never bending chain ring teeth.
6. Chain ring selection is key. There is only one cassette spread available for XX1 (10–42 teeth), so the chain ring choice (from 28 up to 38, in two-teeth increments) determines your gear range. Choose wisely! In our opinion you’re far better off to pick your chain ring based upon the lowest gear you’re likely to use. Swapping the chain rings is very easy, however, because you don’t need to remove the cranks. It’s so easy you could just purchase a couple of chain rings and change them out according to the conditions – keep a bigger ring in the tool box if you’re heading to a flatter race.
7. SRAM’s bottom brackets still suck. We found the installation process with SRAM’s GXP bottom bracket pretty fiddly, especially compared to Shimano’s seamlessly simple systems. There are a bunch of spacers and rubber bearing covers that just didn’t play nicely, not even when we followed the instructions. The system also requires you to tighten the cranks very, very tight in order to get it all to cinch together without any play. It’s a little unnerving the first time you do it.
8. Chain strength. We remember when 10-speed was first introduced and the mountain bike world was quick to cry out that we’d be swamped by broken chains. It didn’t happen. In fact the new 10-speed chains proved tougher. But with the advent of 11-speed, SRAM has had to go narrower again. And this time around, it seems that perhaps it has been hard to retain that same strength in the chain.We’ve witnessed XX1 chains snapping twice – including seeing Chris Jongewaard’s chain snap during an eliminator round at the National Champs. The chain on our test groupset has been fine to date, but we’re not putting out the same kinds of watts as Jongewaard and many bigger riders.
9. Compatibility. XX1 uses a completely new freehub body design – the XD driver system – to accommodate the tiny 10-tooth cog and handle the leverage forces from the large diameter 42-tooth. This means you can’t just whack the system onto any old wheels – you’ll need a rear hub that’s compatible. Fortunately, there is an increasing number of brands now manufacturing XD/XX1-compatible freehubs that can be retrofitted to existing wheels. Of course, this doesn’t include Shimano, the world’s biggest producer of hubs.
10. Silence! A quiet bike is a fast bike, and nothing is as quiet as XX1. The combination of the Type 2 clutch derailleur, which keeps chain slap in check, and the absence of a front derailleur means there’s no rattle. We removed the chain slap protector from our Trek Superfly and replaced it with lightweight Framewrap and the bike is still deadly quiet.
11. The possibilities are incredible. Doing away with a front derailleur has some obvious advantages (weight reduction, less complicated, cleaner appearance and cabling, better mud clearance and many others) and some less obvious advantages too, particularly when it comes to frame design.
Front derailleurs are tyrants of mountain bike frame design. Squeezing in a front derailleur limits how robust you can make the lower pivots point on full suspension bikes, having implications for frame stiffness. All kinds of horrendous asymmetrical formations are required to fit a front mech in too, increasing manufacturing costs. Front derailleurs cause all kinds of headaches when it comes to wheelbase lengths as well, forcing bikes (particularly 29ers) to run much longer chain stays than is ideal. Broader adoption of single-ring drivetrains will solve many, many problems. If the only price to pay is an ever-so-slightly reduced gear spread, sign us up to a single-ring future.
ONE. AND ONLY. SRAM XX1 was built with a dedicated 1X drivetrain philosophy—making it simpler, lighter and more durable than any other. No matter where you ride, no matter what you’re up against: SRAM XX1. UNSTOPPABLE.