Brakes & Gears Etc

SRAM GX Eagle 1×12

Lower priced twelve speed shifting now dominant on 2018 bikes

It’s just over a year since the launch of SRAM’s premium pricED XX1 and XO1 twelve speed Eagle transmissions. Now SRAM GX Eagle gives all the benefits but with a more down to earth price tag and only a small weight penalty.

Words: Sean White  Images: SRAM (Mick Kirkman)


We’ve always been fans of the single chainring approach to gearing and when SRAM launched the groundbreaking XX1 1×11 transmission five years ago we were sold on it after one ride. Here was a drivetrain that was designed as a complete system with every component having a redesign. And so it was with the Eagle twelve speed – an all-new chainring, chain and the cassette with a huge spread of ratios. ‘A total revamp, an extra gear and a massive 10–50 tooth spread!’ is how we summed up this new innovation. This wide range cassette allowed either an incredibly low gear ratio, or the ability to increase the highest gear (using a larger chainring) while still giving you a bottom gear to climb most gradients.

All this comes at a price though. The exquisitely constructed twelve cassette (although very hardwearing) and the rear derailleur commands a very high purchase price and this Eagle transmission is usually seen on premium custom builds or top of the range production bikes. Until now. For 2018 production bikes and for aftermarket upgraders SRAM have launched a 1×12 version of their GX level drivetrain. Now the current 1×11 GX kit has always been a hit on many of the £2-3K test bikes that roll though our doors and won a place in the 2017 Dirt 100.

Step forward GX Eagle, SRAM’s newest addition to their 1×12 drivetrain range. Most of the technology, innovation and thinking that goes into the XO1 and XX1 level kit but with a more economical construction, a little less polish and a touch more weight. If the current SRAM GX components are anything to go by this new hardware will be more than up to most types of riding. There’s no carbon crank but of course you can mix this drivetrain with that of the XO Eagle (or even XX…) if you wish.

‘GX is seemingly bombproof, reliable, with no problems to report. We definitely used this drivetrain far above its intended purpose’

This was how we summed up the original eleven speed version of SRAM’s mid priced hardware. After two wet and filthy days of testing a ‘box fresh’ GX Eagle 1×12 drivetrain earlier this spring, we can report that it seemed to carry on these qualities and didn’t disappoint. Long term test bikes with XO1 and XX1 Eagle have also ‘not missed a beat’. Impressive stuff, and were looking forward to putting some serious mileage onto our test GX Eagle transmission to see just how it can handle a full twelve months of UK riding and just what the running costs are…


Here’s a break down of the new SRAM GX Eagle transmission with listed weights and current UK retail prices. Weights/prices in brackets are for XO Eagle for comparison. NOTE: Cranks will vary with bottom bracket spec and chainring size (GX is 610g – 662g) but below we are comparing the 7000 series aluminium GX and carbon XO with the listed weights for a 175mm length, 24mm axle and 32T chainring spec.

CRANKS: GX 628g £107 GXP/£148 BB30, (XO 495g £328/353)

CASSETTE: GX 450g £170 (XO 360g £302)

REAR MECH: GX 290g £93 (XO 276g £185)

TRIGGER SHIFTER: GX 122g £30 (XO 126g £112)

CHAIN: GX 270g £25 (XO 250g £50)


TOTAL TRANSMISSION PRICE: GX £425/£466 (XO £977/£1002)


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