Many riders were stoked when SRAM launched their 12-speed GX Eagle
drivetrain last year. It offered a high level of performance at a more affordable price than its XX1 and X01 Eagle siblings. Now, that technology is available at the NX level with an even lower price tag.
SRAM also moves away from the XD driver body for NX, with the 12-speed cassette mating with a standard 8, 9, 10 speed splined SRAM or Shimano driver body - which will further increase compatibility and allow upgrades to a 1x12 system without having to switch drivers.
SRAM NX Eagle Details
• 1x, 12-speed drivetrain
• 11-50 tooth cassette
• 8, 9, 10 speed splined driver body compatible
• DUB BB compatible
• Weight: 2049 grams
• Price: $375 USD
• Available: September 2018
GX Eagle was half the price of the XX1 Eagle and had similar performance. Priced at only $375 USD, (shifter, derailleur, cassette, cranks, chainring, and chain), the new NX Eagle system is even easier on the wallet and it still performs incredibly well. It does come with a weight increase 202 grams, but the functionality of the group will be difficult to tell apart. The big story with NX is the cassette. Rather than requiring an XD driver body, it mounts on the tried and true splined drivers common to SRAM and Shimano 10-speed freehubs, which are a lot more common and also less expensive. That's good news for companies trying to pack even more value into their entry- to mid-level bikes - this gruppo will likely be a common sight on bikes in that price bracket for 2019.
NX Eagle is compatible with all SRAM 12-speed Eagle drivetrains (meaning you can mix and match parts). More compatibility is always better in my mind, especially when you've already emptied your piggy bank on gas and ramen to get to your summer riding destination, then inevitably crash and damage part of your drivetrain on your first day there.
There are a lot of similarities in the NX Eagle drivetrain with GX Eagle but, the cassette is a different story.All New Cassette
The big change for NX Eagle is the splined-driver-style cassette. The XD driver that SRAM has been using for the last several years works well and is great in terms of making a lightweight system with a wide range of gears. However, when it comes to compatibility across wheelsets, for those looking to switch from a lower end drivetrain, or anyone already using a splined driver body, the associated costs to switch to the XD driver can add up quickly. If you are lucky, you'll just need to buy a new driver body, but a lot of hubs don't have that option, so you would be looking at a new wheel or wheel-set in addition to the drivetrain, making what was at first a somewhat affordable GX Eagle upgrade quickly double in price.
The new NX Eagle cassette mates right up to an 8/9/10 speed splined freehub, so you can't have that ten tooth cassette cog. NX cassettes begin with an 11-tooth, sacrificing a tiny amount of gear range. Some people may want to pick this apart as a negative, but really, most aren't going to notice a difference and if you do, you can always use a larger chainring.
The 11 by 50 tooth cassette mounts on a standard splined driver body.
The cassette is made out of 12 stamped steel cogs. The largest four gears are bound together with stainless steel pins and then the rest of the cogs slide onto the freehub body individually. There's a normal lock-ring holding everything together, and as a side note, the NX cassette is also the only Eagle cassette designed to be strong enough to use on E-Bikes. The 50-tooth bail-out gear, as some call it, could actually bail you out if you run out of power on a big e-xcursion. The NX Eagle cassette weighs 615 grams and retails for $100 USD - yes, it's heftier than GX by 167 grams, but it's also $95 less.
The NX Eagle crankarms are 6000 series forged aluminum. They are designed to be used with SRAM's X-SYNC 2 chainrings and interface with SRAM's DUB bottom bracket system. They're available in 165mm, 170mm, and 175mm lengths and come with a 32 tooth steel chainring for $105 USD.
Shifter, Derailleur, and Chain
The NX Eagle shifter, derailleur, and chain are very similar to the GX versions. There are no major changes between the two groups, and NX shares all
of the same features, benefits, and technologies as GX. The biggest difference is NX components are manufactured from more affordable materials and weigh a bit more. The shifter sells for $42, the derailleur for $107, and the chain for $26 USD.
The shifter is no frills, but still it's still Matchmaker compatible and it functioned flawlessly.
I have been riding the NX Eagle group for almost two months at this point. A lot of that time has been in rain and mud, optimal conditions for accelerating wear on a drivetrain, and I have zero complaints with the NX group. Comparing it to the GX group that I had been running on the same bike for a few months prior, the shifting and overall performance are nearly impossible to tell apart.
The shifter is smooth and firm in its action. The large paddle tends to be the first piece to loosen up on any shifter as it wears, especially on more budget oriented models, but the NX has stayed firm and there's no play in it to date. Although it lacks the adjustability of the higher end XX1 and X01 models, it's comfortable and by no means feels "cheap" as some other more affordable shifters do.
I have not dropped or broken a chain, and despite the poor conditions I've ridden in, the drivetrain is as quiet as any other Eagle group in those same elements. From the small cog to the 50-tooth bail-out gear, everything is smooth, quiet, and crisp both up and down. I am starting to notice some wear on the finish of the cassette in my more commonly used gears, as to be expected, but performance has not degraded in any way.
I really can't find anything to pick apart in this drivetrain. It simply works and works well, at that. Yes, it's heavier, and maybe a little clunkier than XX1 or X01 Eagle, but you can also buy the entire drivetrain for less than what a XX1 cassette costs. As far as practicality and ease of use, it's exactly what it should be.Pinkbike's Take: