SRAM has unveiled an all-new mountain bike drivetrain. Badged GX, the new group is available in 1x and 2x configurations and replaces SRAM’s long-standing X7 and X9 component lines.
Most importantly, GX signifies 1x transmissions taking a big step up in affordability, with the cost of a complete 1x GX group dropping in at £451/ €588/US$564, a massive saving over the cheapest 1x dedicated transmission currently on sale – SRAM’s own X1 group.
Like XX1, X01 and X1, GX in 1x11 and 2x11 configurations features a full 10-42t cassette and uses the X-Sync chain retention technology that SRAM’s mountain bike groups are now renowned for.
OE Implications and cheaper spares
The OEM take up of GX1 is an exciting prospect, particularly with SRAM telling us to expect GX on bikes as low as €1,000. To put that into perspective, the cheapest X1-equipped bikes this year are still around the €1,799 mark.
We can also expect manufacturers to mix and match the cross compatible GX1 components with the company's other 1x specific groups, say placing a GX shifter and cassette with an X1 derailleur. Cross compatibility means that current SRAM XX1, X01 and X1 owners will be able to replace broken or worn out parts with these simpler but heavier components if desired.
Shimano’s slowness to deliver a 1x solution and the cost of SRAM’s current 1x groups has meant a barrage of conversion and aftermarket components has entered the market. Swapping out OE kit for wide range cassettes, derailleur cages and narrow wide rings has become the norm as riders try and get the advantages of a 1x system as cost effectively as possible.
Sometimes these components simply don’t work as well as intended and durability of parts can be affected. This is where GX gets the upper hand – by being extensively tested and sold as a complete system each component is designed to work with each other and durability, as with SRAM’s other 1x groups, should be strong.
Compromise in the right places
What SRAM claims to have done with GX is offer the same shifting performance as its other dedicated single ring drivetrains but at a fraction of the cost. So, just how has it managed to take so much off of that retail price? Well, it’s not just a case of making X1 components a bit heavier – that’s for sure.
To reach the desired sweet spot between weight, durability and cost of manufacturing, GX has swapped out some fancy for functional and introduced unique construction methods including a rather special cassette.
On paper, using SRAM’s own claimed weight information, the GX group starts at a smidge over 1.7kg – just 78g over that of the lightest X1 configuration.
SRAM hasn’t phased out 10-speed shifting entirely and a 2x10 version of GX will be available with a choice of two regular range 10-speed cassettes.
1x11 Component breakdown
SRAM admits that this was the most challenging component to produce more economically. Whereas XX1 and X01 get a cassette extensively and expensively machined from stainless steel and X1 gets a cost cutting partially pinned alloy/steel item, GX had to reduce costs further. SRAM’s solution arrives in the form of an entirely pinned item that consists of only pressed steel cogs.
The result is a claimed 393g part, only a 78g penalty over the X1 version. There’s also the familiar corrosion preventing black finish, 10-12-14-16-18-21-24-28-32-36-42t gear ratios and exclusive compatibility with XD driver bodies.
Pricing is US$144/£115/€150
GX rear derailleur
The GX rear derailleur holds the same technologies as its more expensive siblings including the horizontal parallelogram design, roller bearing clutch and handy cage lock function. Two offset 12-tooth pulleys feature the same X-Sync chain retention technology of SRAM chainrings; these work to reduce side to side chain movement and provide better guidance for shifting.
To keep costs down certain alloy parts take a shift from being forged to die-cast. It’s not as pretty and a bit of weight has to be added to achieve the same levels of strength. The claimed weight penalty over X1’s components is just 9g though.
Pricing is US$115//£92/€120
As far as shifting is concerned GX is available with both trigger and gripshift hardware options. The former is a 122g component that looks near enough identical to that of X1 and retains its multi-position mounting bracket and MatchMaker compatibility.
The grip shifter weighs 144g and looks near enough identical to the part that already exists on X01 and XX1 configurations.
Trigger shifter – US$43/£34/€45
Grip shifter – US$52/£42/€54
GX cranks will come in two alloy flavours – the GX1400, a 680g part that makes use of SRAM’s Open Core Technology and a cheaper, simpler, and slightly more portly GX1000 version at 720g. GX cranks are available with a 24mm or 30mm spindle with options to fit PressFit 30, BB30, GXP and PressFit GXP bottom brackets. Compatibility also extends to the new BOOST148 wider axle standard.
From US$120/£96/€125 to US$225/£180/€235 depending on configuration
SRAM has chosen to use the same 258g 11-speed solid pin chain as debuted in its X1 drivetrain.
Pricing is $37/£27.99/€33
1x11 GX group weight comparison
XX1 claimed weight (g)
X01 claimed weight (g)
X1 claimed weight (g)
GX claimed weight (g)
GX is also available as a 2x11 transmission with two levels of double cranks, a front derailleur with several mounting options plus a dedicated double rear derailleur and the same cassette as the 1x11 group. It’s available with either trigger or grip shifters.
Prices for the 2x11 group are as follows:
GX1400 2x11 trigger shifter US$661/€689/£529
GX1400 2x11 grip shifter US$677/€705/£542
SRAM also offers GX in a 2x10 option, this time with only one crank option, a different derailleur design and no grip shift option. GX 2x10 arrives with a choice of two regular range 10-speed cassettes. To easily distinguish the 10-speed kit SRAM has dropped the red accents that you’ll find on other GX parts. A complete 2x10 GX groupset will retail for US$511/€534/£408