If you’ve gone shopping for a new mountain bike in the last few years, you’ve probably noticed the transition away from front derailleurs on the vast majority of new bikes. Bikes with two or three front chainrings have all but been replaced by systems featuring a single front chainring and 10, 11 or 12 wide-ranging speeds in the rear. These one-by systems offer simplicity of use and maintenance, reduce cable clutter, and offer potential weight savings, depending on the configuration. There is, however, a downside to reducing the overall number of speeds in a bike’s drivetrain. For many riders, this downside manifests itself in an inability to replicate the so-called “granny gear” that their old bike’s multi-chainring system provided.

Prior to the advent of the one-by system, bikes with a 3x10 system would feature an easiest gear of something like 22-36, for a gear inch value of 17.62*. Until recently, most common 1x11 drivetrains would come spec’ed with an easy gear of something more like 32-42 (21.96*). Easier climbing gears could be attained, but at the expense of a diminished top end speed that would find riders spinning out on any kind of faster and more open terrain. A combination of 26-42, for instance, makes for a gear inch value of 17.91*, but the diminutive 26t chainring would undeniably prevent riders from pedalling comfortably at high speeds.

Gradually, wider range options became available, as Shimano expanded their 11 speed cassettes to feature a 46t “bailout” cog, and several smaller companies began to offer aftermarket cog options beyond what was available from biking’s Big Two – SRAM and Shimano. Then, in early 2016, SRAM launched its new, 1x12 drivetrain, dubbed Eagle. The new system offered a largest cog of 50 teeth, enabling users to run a 30-tooth chainring and still achieve a generous climbing gear inch value of 17.33*. It appeared to be the answer for riders who had caught the one-by bug, but were yearning for a wider range of gears. There was only one problem: upon its debut, complete Eagle group sets ranged from $1300 to $1800 CAD, thus landing exclusively in the realm of no-expense-spared spenders and pro riders. Initially, many critics chimed in that the extra cog and extended range of the new system was overkill, symptomatic of an endless game of frivolous one-upmanship between the major players in the bike component game. Then a funny thing happened.

In mid-2017, SRAM debuted a new version of its 12-speed group set, dubbed GX Eagle. The GX group set offered the same 10 thru 50 range of cogs as it’s pricy predecessor, but shocked the bike world by arriving at an MSRP of under $700 CAD. What’s more, initial reports on the performance of the newly attainable iteration of Eagle were favourable. In his initial product overview for Pinkbike, Mike Kazimer wrote that its “shifting performance feels almost the same as the pricier X01 [Eagle] group.” All of a sudden, SRAM's new novelty was anything but, and it quickly catapulted into the conversation on preferred shift systems to run on any mountain bike.

What does all this mean for consumers? Two things: One, if you already have a bike that you’re happy with, but are considering an affordable drivetrain upgrade, GX Eagle should absolutely be on your radar. All of SRAM's 12 speed cassettes are installed to the hub via their proprietary XD driver, so you will have to confirm compatibility in that regard. Second, get ready to see a lot of new 2018 bikes coming spec’ed with GX Eagle. Most will likely come stock with a 32-tooth chainring, a pairing which brings the 500% overall gear range of Eagle in realm of the broadest ranging of triple drivetrains. Whether you’re new to the concept of one-by, a familiar user who has always wished for more range, or even someone who has been satisfied with past single-ring offerings but loves new product, be sure to stop by and test ride a bike equipped with GX Eagle. It is, without a doubt, a product you’ll be seeing a lot of in the coming season and beyond.

 * all gear inch calculations based on 29er wheels w/2.2” tires; the lower the gear inch value, the “easier” the gear.