When SRAM's XX1 drivetrain debuted back in 2012 it created quite a stir, thanks to its wide-range, eleven speed 10-42 tooth cassette, and a unique chainring tooth profile that made chain guides optional equipment for riders that chose to get rid of their front derailleurs. There was only one catch – the high price of admission. The XX1 group retails somewhere in the neighborhood of $1500 USD, a price that helped create a burgeoning aftermarket accessory industry fueled by riders that wanted to run a wide-range 1x setup, but couldn't justify laying out the cash to turn things up 11.
SRAM GX Drivetrain Details
• 11-speed, 10-42 tooth Full Pin cassette
• Available in 1x or 2x configurations
• Trigger or Grip Shift
• Open Core aluminum crank arms
• Bottom bracket options: BB30, PressFit 30, GXP, PressFit GXP
• Price: $564 USD
Last year's launch of the X1 drivetrain slightly reduced the cost of converting to a SRAM 11-speed drivetrain, but its pricing still remained on the higher end of the spectrum. That brings us to the GX gruppo, the one that finally tips the scales in favor of affordability. A complete drivetrain, including cranks, goes for $564 USD. Already have a set of cranks and a narrow-wide chainring that you like? Then the price for a new derailleur, chain, cassette, and shifter is $333, although bear in mind that doesn't include the price of an XD driver body, a necessity for running SRAM's 11-speed cassettes.
We covered the nitty-gritty details
of the GX group when it was first announced, but here's a quick rundown of the components, and a look at how SRAM was able to reduce the overall price so drastically.
Cassette: The GX cassette is where a large portion of the cost reduction comes from. It's constructed from 11 chromoly cogs that are joined together with 123 stainless steel pins. Using those pins rather than machining the whole assembly from one chunk of steel (the method used for the XX1 cassette) does create a heavier final product, but it greatly reduces the cost, and the 401 gram XG 1150 cassette retails for $144 USD. For comparison, an XX1 cassette costs $416 and weighs 260 grams.
Shifter: Once again, the GX shifters are nearly identical to their X1 relative, with an aluminum thumb paddle for upshifts and a smaller composite paddle for downshifts. There are two mounting position to help get the distance between the lever and a rider's thumb just right, and the unit is also Matchmaker compatible, allowing it to play nicely when it's used in conjunction with SRAM's brakes.
Derailleur: Visually the GX derailleur looks very similar to an X1 derailleur, and the weight difference between the two is less than 10 grams. It has all the features we've come to expect from SRAM's higher end derailleurs, including version 2.1 of their roller bearing clutch design, and the Cage Lock system that (as the name suggests) locks the cage into a forward position for easy rear wheel removal.
Cranks: The GX 1400 crankset's hollow crank arms are constructed from 7075-series aluminum, and are joined to either a 24mm or 30mm spindle depending on the bottom bracket being used. A four bolt, 94mm BCD pattern is used to hold the X-Sync chainring on, but it is possible to remove the spider and install one of SRAM's direct mount rings, which are available all the way down to a 26 tooth option, just in case you plan on pedaling up a vertical wall.
On the Trail
Although there may be a significant price difference between the GX gruppo and its more expensive siblings, out on the trail the performance is remarkably similar. Each click of the shifter is met with a positive response from the rear derailleur, and it's easy to tell when the chain has moved to the next cog. The shape of the thumb paddle on the GX shifter, the one that's used to move to an easier gear, is ever-so-slightly different than that found on an X1 shifter, but the action feels identical. It's possible to move up through five gears with one push of the larger lever, and the smaller trigger moves the derailleur down the cassette one gear at a time. Throughout the duration of the test period, shifting was accurate and precise, without any ghost shifting or odd behavior. This particular drivetrain spent time on two different bikes, and ended up being impressively low maintenance - other than a minor cable tension tweak no other adjustments were needed.
The best components are ones that don't call attention to themselves, and that proved to be the case with the GX crankset. Once installed, there weren't any issues, just smooth spinning no matter the conditions. The fact that they can accept a direct mount chainring is a nice touch, an option that will be welcomed by riders seeking easier gearing or just looking to save a little bit of weight. Given the GX 1400's ability to accept chainrings ranging from 26 all the way up to 38 teeth, it's simply a matter of picking the size that best matches the terrain you ride most frequently and going from there.
The overall durability of the GX group has been downright impressive. The rear derailleur now bears a few scratches and scars from close encounters with rocks, but it's still shifting smoothly, and there's no excessive play or noise coming from any of the pivots. Even the little pulley wheel that the cable is routed around is spinning freely – I thought for sure that the mud and grit would have gummed it up to some degree. All of the pins in the cassette are still securely in place, and the wear on the cogs is relatively even and on par for the number of miles it's seen.
As far as functionality goes, the GX drivetrain was completely trouble free – the derailleur and shifter both withstood months of abuse, and they still have plenty of life left in them. I do have two small wishes though, wishes that apply to all of SRAM's mountain bike drivetrains and not just GX. They may not be possible due to patents held by Shimano, but it's worth a try.
The first request would be for an adjustable clutch. Previously, even though it wasn't specifically advertised or recommended by SRAM, it was possible to increase the clutch tension on Type 2 derailleurs by removing a plastic dust cap and turning the large torx head bolt hidden underneath.
Type 2.1 means you really, really can't adjust the derailleur's clutch mechanism.
Newer derailleurs are marked as being Type 2.1, and have a pin that holds the bolt into place, making increasing the tension impossible. There was enough tension on the GX derailleur to keep the chain on without a chain guide, but I would have liked to be able to increase it a little bit in order to reduce the amount of chain slap.
The other request would be to have the ability to drop multiple gears with one push. If you're currently on a SRAM drivetrain, think about how many times you 'click, click' through two gears at a time. It'd be great to be able to push the smaller thumb paddle a little further and be able to drop two gears instead of one.Pinkbike's Take:
|For riders who are interested in giving a 1x11 drivetrain a try, the GX gruppo drops the price of admission even further, and offers nearly identical performance to SRAM's higher end offerings at a much lower cost. The extra weight is really the only penalty that the more wallet friendly components incur, and if those grams are truly a concern they can easily be shed by ponying up for a lighter cassette. This is the trickle-down group that riders have been waiting for, and there's no doubt that we'll be seeing it specc'd on plenty of complete bikes in 2016. - Mike Kazimer|
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