SRAM GX Eagle Transmission Review – The Perfect Sweet Spot

Almost all my singletrack miles in 2024 were tackled with SRAM GX Eagle AXS Transmission. As their newest Eagle Transmission drivetrain, it’s the most affordable and arguably the best-designed rear derailleur of the bunch. And, it’s outfitted on a plethora of stock builds from almost every manufacturer. With it, you can be confident of smooth, accurate shifts under all conditions and on any terrain.

SRAM GX Eagle Transmission Features:

• Available with 165, 170, 175mm crankarm and 32T chainring
• Bashguard compatible
• GX Eagle Transmission derailleur
• 10-52T GX Eagle Transmission cassette
• GX Transmission Flattop chain
• Pod controller
• AXS battery/charger
• Syncs with SRAM AXS mobile app
• MSRP: $1099

GX Eagle Transmission Setup & Configuration

This year, I’ve had both the Trek Supercaliber SL 9.1 Gen 2 and the Ibis Exie USA. The Supercaliber came dialed in from the factory with perfectly-crisp shifting, but I did have to set up and configure GX Eagle Transmission myself aboard the Exie. So, I’ll briefly cover the initial setup process.

Since I hadn’t yet set up a Transmission rear derailleur, I installed it just like I would a traditional derailleur and thought it was good. Well, I was wrong. Getting the GX Eagle Transmission (XX SL, XX, X0 too) dialed in first starts with a UDH frameset which SRAM then uses for their Full Mount system. Without question, this achieves the most durable and stiff derailleur attachment to date by eliminating derailleur hangers and their inherent flaws. From there, it does also require a T-type Eagle cassette (all included with the GX kit). Both the mount and cassette work together to facilitate the proper setup.

In short, the setup is easy, but totally new from drivetrains of the past. Here’s a list of what you will do, followed by the SRAM’s technical video guide.

1. Use SRAM AXS app to obtain the proper chain length and setup key position
2. Use those settings to configure your derailleur, set chain length and sync components
3. Shift the derailleur into either the 21 or 24T cogs, based on setup instructions
4. Install derailleur snug, then back out the bolt slightly so it hangs loosely
5. Open the derailleur cage and lock into place
6. Thread the chain into place and lock the PowerLock link
7. Pull the derailleur rearward to eliminate any chain slack
8. Tighten the mounting bolt and thru-axle to spec
9. Push the setup key button down
10. Verify all shifting and proceed to shred

Following these instructions is easy and key to obtaining proper performance. My initial setup on the Ibis Exie USA was no bueno (totally my fault), but after following the above procedure, it has been smooth sailing. Another noteworthy point… SRAM Eagle Transmission cassettes are required with any Transmission drivetrain. I installed an X0 Eagle cassette briefly for one ride and the performance was severely degraded.

And, with all pre-Transmission SRAM AXS components, you could mix-and-match everything to achieve the desired setup for any drop bar or mountain bike. However, keep in mind that Transmission does throw a caveat into that where only Transmission cranksets and cassettes are compatible. Shifters are interchangeable, but stick with Transmission components elsewhere.

GX Eagle Transmission Meets Dirt

Once configured and personalized to my liking, I proceeded to rip the local trails on two different bikes throughout the year. As with the X0 Eagle Transmission I tested last year, the SRAM AXS App is your BFF to tweak settings and manage all firmware updates (which are a breeze, btw). Once the shift pod is in place, shifting becomes intuitive and natural — no matter the terrain.

With SRAM’s Full Mount design, mis-shifts and adjustments are pretty much a thing of the past. Any fine-tuning can take place with the shifter pod on any flat surface. One set up, I didn’t have to do anything through months of aggressive riding. Frames look cleaner without extra cables and the mess of spaghetti cables is simplified — even further with the RockShox Reverb AXS Dropper.

Of course, all drivetrains will shift well on smooth terrain, but where the GX Eagle Transmission shines is on undulating terrain. And, particularly, when tackling sudden climbs when in the wrong gear. That has proven to be a lifesaver on many occasions. Specifically, when descending Upper Mill Creek Canyon from the Wasatch Crest Trail, the trail suddenly pitched upward on several occasions as it snakes through north-facing pines. After long descents, these sudden upticks can wreak havoc on mechanical groupsets, but with GX Eagle, I can shift under the most extreme standing loads as I try to make up for my lack of foresight. It doesn’t mash the gears, but quietly ticks up the cassette to keep me going. The same behavior would undoubtedly cause cringe-worthy gear mashing with mechanical systems.

Admittedly, these accurate shifts are a touch slow (as I’ve noted before), but that millisecond of wait time doesn’t detract from the accuracy and reliability of GX Eagle Transmission. When climbing or descending, I’m not losing sleep or becoming distracted because it shifts perfectly 99.9% of the time. The only hiccup I’ve felt has been on a steepening, off-camber switchback climb when the suspension compressed just as I was trying to shift gears. I wouldn’t even call it a mis-shift, but a slight momentary hiccup.

There’s not much to say about the GX Eagle Transmission crankset. It’s stiff, durable and capable. I think it looks great and chain retention has been excellent. You can change the chainring as desired and the finish has remained intact throughout all my testing.

While the SRAM Full Mount ensures the rear derailleur and frame is protected, it’s nice that the GX Eagle Transmission is also rebuildable should stuff hit the fan. It’s a very expensive part and I appreciate that it can be fixed without full replacement. I also prefer the tucked-in battery placement as opposed to the one hanging off the back of the higher-priced derailleurs. It’s nice having it completely out of harm’s way.

Getting Nit-picky

I have gotten used to the AXS Pod Controller and we get along, but it’s not my favorite. Yes, it makes hitting the buttons easy and the mounting system is surprisingly-adjustable to get it into the right position. However, I remain a fan of the GX Eagle AXS Controller. Instead of deliberate thumb presses on the Pod, I appreciate the more subtle up/down push and still find it easy to access with urgency. Additionally, the AXS Controller offers shifting without moving your thumb all the way to the front of the controller by using the back of my thumb. For my own bikes, I would 100% choose it over the Pod controller. You can read my thoughts on this in my GX AXS Upgrade Kit review.

Electronic groupsets are amazing — I’m not gonna lie. But, if you’re an infrequent rider, tend to be forgetful, or are a seasoned rider, take 10 seconds to do a full system test before every ride. It only takes a second to test battery life. And, go ahead and pick up a spare battery so you always have one at the ready. When traveling long distances, remove the battery and put in the blank to eliminate any battery drain whatsoever.

While I have become accustomed to electronic drivetrains in recent years, by no means are mechanical groupsets dead. I absolutely love SRAM GX Eagle and the price point makes for a much more wallet-friendly build. But, if you’re going to go electronic on your singletrack machine, this is hard to beat.

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