There are two main differences between NX and the groups above it (GX, X1, X01 and XX1), and they both concern the PG-1130 cassette. Because it mounts onto a standard splined freehub body rather than a dedicated XD driver, the smallest sprocket has 11 teeth, not 10.
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That’s a big difference in percentage terms (382 vs. 420 percent), but we rarely use the 10t cog on other set-ups so it’s less of an issue on the trail. Being able to fit the cassette straight onto your existing freehub is useful though, saving you the cost of an XD driver and potentially a whole new rear hub/wheel.
At 545g the £68 / US$79 / €89 / AU$125 NX cassette weighs nearly 220g more than the £115 / US$155.25 / €138.00 / AU$204.70 GX block but the steel sprockets are more durable. The 110g difference between NX and Shimano’s XT cassette is much smaller too. Back on the trail, there’s no obvious difference between the cog-to-cog movement of the NX cassette and more expensive SRAM or Shimano blocks, and the shifting is definitely faster and slicker than with an aftermarket wide-range cassette or expander sprocket.
Testing them back to back, the action of the NX shifter (£22 / US$30 / €27 / AU$40) is noticeably less crisp even when new than GX (£38 / US$52 / €46 / AU$68) and slightly more strained after a few months. NX also has a built-in rather than bolt-on shifter clamp, which means it can’t share Avid/SRAM lever mounts.
The cheap (£11 / US$14 / €14 / AU$20) PC-1110 chain also needs lubing more religiously than more expensive options so we’d suggest upgrading to the PC-1130 if you can. NX is still a massive step up, in terms of sharper shifts and resilience to dirty cables, than SRAM’s older 10-speed groups though. You’re getting all the sequential shifting and weight, space and clearance advantages of a dedicated single-ring set-up as well.
The chainring itself (30-38t) is a good one too. SRAM’s ‘X-SYNC’ narrow/wide tooth profiling still sets the benchmark for quiet, smooth, secure shifting and NX feels no different. While there’s no direct-mount ring option on the acceptably stiff forged cranks, they do come in a range of lengths (155 to 175mm). There’s a BB30 version (£115 / US$155 / €138 / AU$205) and the chainline is compatible with Boost rear axle spacing.
Overall, that means we’ve been thoroughly impressed by the several sets of NX we’ve ridden extensively this year. It delivers all the simplicity and durability that we love SRAM’s 1x11 transmissions for, and for £200 / US$254 / AU$323 less than GX.