It may seem like the high-end Transmission kits just hit the market a few weeks ago, and that's because they did. In quick succession, we're now met with the more budget-conscious version of gruppo, meant to provide all the magic of the T-type system to a wider audience. In order to hit the lower pricepoint that GX looks to strike, SRAM did some clever re-engineering of the derailleur architecture, cutting material and cost where possible.
That may sound like the means of creating a cheaper-feeling and less robust drivetrain, but let me head that off by saying that the GX kit performs just as nicely as the X0 group I've been running for the past few months. Same wireless elegance, same improved clutch tension, and same fantastic shift quality.
GX Eagle Transmission Details
• 12-speed, 10-52 tooth cassette
• Direct mount, wireless electronic rear derailleur
• Flattop chain only
• Price: $1,099 USD (cassette, derailleur, cranks, shifter, chain, battery, charger)
The price is lower, the color is more grey, and the cranks are free of holes. I've been testing (read: abusing) GX kits on three different bikes, so let's dig into the similarities and differences to the other tiers of the T-type family, and see just how well the "people's champ" holds up. Battery
Same as ever, but tucked away from harm. The main visible difference in GX Transmission's derailleur architecture is the battery location, now slotted nicely right underneath the axle. The plastic clasp is now replaceable, so you'll still be able to clip that puppy in if things get banged up.
The lifespan of that battery is still excellent, with my highly technical mental clock timing out well before ever having to replace a battery on any of my three test bikes. I always carry a spare regardless, but you can rest assured that the little robot will keep zipping around for many a ride.Clutch
In my experience so far, the clutch is one of the better improvements to the overall system over the prior AXS drivetrains. My primary complaint with old AXS was just how weak the clutch mechanism was, as it barely seemed to fight any sort of trail chatter or hard impacts. The rattle and misshifts that would occur as a result were frustrating to say the least, but conceptually the wireless action was enough to keep me intrigued. Come the advent of the Transmission system, and those clutch woes were all but gone away.Cranks$200 USD
They are, in fact, cranks. Rejoice, all you who like a sturdy metal object. These handsome grey pedal holders are available in 175, 170, and 165mm lengths, and all feature SRAM's new 8-bolt chainring mounting standard, which facilitates the use of their new power meter rings and bashguard/chainring combos. Speaking of the latter, I actually prefer the performance of the cheaper plastic bashguards to the admittedly sexier raw aluminum ones seen on the XX models. Like a good pair of plastic pedals, they glide rather than catching when you smoke a rock, letting momentum keep on a little longer.
As you can see, these have seen their fair share of rock strikes, but the chainring remains unaffected. Overall, I'd say the GX cranks show use and abuse more readily than the aluminum X0 counterparts, but there's something about rugged handsomeness to be said here. Considering the fact that they're half the price of X0, I'm okay with a few more scuffs and rub marks.
They're a bit portly, clocking in at 740 grams for the 170mm variant. That's about 55 grams heavier than the XO crankset, but I wouldn't recommend drilling two -27.5 gram holes in the GX ones, just accept that increased heft. Cassette$250 USD
Thankfully, nothing has been done here to decrease the quality of the shifting, but weight does take a penalty. At 445 grams, the GX cassette is 60 grams heavier than the X0 equivalent. Not a ton, but that will matter to some. The pinned construction hasn't produced any creaks, and the chromed-out look is holding up so far.
One of my favorite attributes to the Transmission system is the smoother gear progression, and that carries through to the new kit. Pedal hard, shift whenever, and the change in mechanical advantage is smooth and intuitive. Chain$50 USD
Half the price, 286g at full length, and featuring a flat top. Not too much to say about a chain, but if old truths hold up, the X0/XX version may prove to be a bit more durable in time, though performance is indistinguishable. I'll be playing with combinations of all three tiers in time, so we'll see what proves to be the best bang for your buck. Derailleur$400 USD
$150 cheaper and 6 grams heavier than the X0 derailleur, the new mech casts a much different shadow, but manages to shift just the same. However, here lies my only complaint with the GX system - the construction uses two halves bolted together to get that Full Mount
attachment that allows you to toss your derailleur hanger. Compared to the one-piece construction that the X0 and XX versions use, the GX one can feel a little less stable, but really that's only a difference present in hand. The noise, security, and durability seem to be the same so far, but we'll see how things shake out after a few more months at the Whistler Bike Park.
Speaking of which, that's the only place I was able to produce a single issue with the GX Transmission. After days of hitting rocks and bottoming out the Nomad I've been riding, the derailleur's mounting bolt came loose, causing some rattling that I quickly noticed. Luckily, thanks to the easy setup procedure, I was able to fix this trailside, getting things back up to power-shifting perfection in no time. Full Monty$1099 USD
A grand for a drivetrain is still a hard pill to swallow, but if you're after the finest shifting in the game right now, that is currently the lowest price of entry. I've come away from many trail miles impressed, and it might just be enough to get me off my 11-speed setup. In my mind, the weight difference is negligible, and the shift quality is damn near the same, so the choice really comes down to aesthetics and status. If you fancy yourself more of an X0 rider, then you're welcome to spend the extra $600, or double the price for a truly baller XX kit. My money is probably going to be on the GX, perhaps with a mix and match combo of the X0 cassette and chain, should they prove to be more durable in time.