SRAM AXS technology is a wireless electronic platform that controls shifting and dropper posts.
Launched in 2019 and originally only available in their top-of-the-line component range, the technology has now trickled down to the more affordable GX range.
I’ve spent two months putting the system through the wringer to see how it rates against its pricier siblings, exploring reasons to upgrade, reasons not to upgrade, and generally, what it’s like living with electronic shifting.
The most affordable path to wireless mountain bike shifting is with the SRAM GX Eagle AXS upgrade kit. The kit consists of a rear mech, the shifter that SRAM refers to as a controller, a charger and the battery. This is pretty much all you need to convert any SRAM 1 x 12 drivetrain to a wireless electronic setup. It’s priced around R12 400 plus R600 for the more ‘traditional’ feeling, Rocker Paddle.
|SRAM GX EAGLE AXS UPGRADE KIT|
|| AXS Controller with standard paddle|
|| AXS Rear Derailleur|
|| SRAM AXS Battery|
|| Battery cover|
|| Charger and cable|
|| Extra: Rocker Paddle|
|| Approximately R13 000|
On appearance, the GX AXS controller and derailleur are virtually identical to that of the XX1 and XO1 systems. Internally, the AXS systems on XX1, XO1 and this GX range, are very similar. The main difference seems to really only be with the material SRAM used to make the derailleur cage. The XX1 derailleur features a carbon cage and weighs +/-375g. The XO1 derailleur features an aluminum cage and weighs +/- 390g whereas the GX AXS derailleur has a stamped steel cage and weighs 454g. For everyday riders the extra couple of grams in the stamped steel cage is negligible and the upside of a steel cage is its strength. We hear there are some small differences in the bearings and pulley wheels however we have been reassured the battery, circuitry, gearbox and motor inside the GX AXS system is identical to that of the opulent XX1 and X01 models.
In terms of installation, if you are able to fit a regular derailleur onto a bike then you’ll find the installation of the GX AXS system, a walk in the park. Being wireless, there is obviously no cabling or internal routing to hack through and that speeds up the process significantly. Setting the gears is also a simpler process than with a cabled derailleur and there are plenty of videos available to walk you through it all.
There are two batteries involved with the system. A regular CR2032 disc battery powers the controller and will run for around two years (average riding) before needing replacement. The AXS specific battery which attaches to the derailleur weighs 25g by our account and will give around 20 to 25 hours of riding time. The battery is protected by a plastic cage and throughout this test period (and through hundreds of hours of ride time on other bikes with AXS) I never lost a battery on the trail. To preserve and extend battery life, the system automatically goes into sleep mode when the bike is stationary. To check battery life all you need to do is push a button on the derailleur; a green light signals a full charge, a red light signals it’s at half charge, and a flashing red light signals it needs a charge. The charge time is about an hour and I got into the routine of just charging it once a week.
How does it work? In essence, you touch a button to shift gears instead of pushing a cable-actuated lever. The controller has a ‘rocker paddle’ which you’ll touch with your thumb to shift either up or down. Additionally, this rocker paddle can be touched with the knuckle or tip of your index finger which comes in handy when needing to shift gears when you are out of the saddle.
The upgrade kit ships with the standard style paddle shifter but there is a more traditional feeling paddle lever available which I used in this test and I’d recommend it. With the AXS App, you can customize your controller to shift multiple gears at a time and change the function of each button. I set the controller in a forward (or down) position on the handlebar which meant I could use the ‘sprint button’ more often and my thumb had more wrap around the grip, with less reaching needed to access the buttons.
I’ve done a lot of riding and a video review on the range-topping XX1 AXS system and am pretty familiar with its slick performance and reliable operation. Here’s the clincher, with the lower-spec and way more affordable GX level AXS, I can’t say I felt any difference in shifting performance when comparing with its richer brothers. In fact, GX AXS performs so well I can’t stop wondering how on earth SRAM will ever sell any XO1 and XX1 AXS systems…
I like the GX cable shifting setup but the performance gap between it and GX AXS is significant. The electronic system shifts gears faster, the shifts are almost silent and with 100% reliability – even when under power. The comparison is chalk and (Swiss) cheese. For cross-country and trail riding I found I’m actually shifting more with the AXS system than with the cable system. On undulating trails, the button-style shifting makes it very easy to keep the cadence optimized.
In my opinion, one of the main reasons to look at upgrading is the overload clutch system. The derailleur has the regular clutch system – seen on other SRAM derailleurs – which keeps tension on the chain but also has an overload clutch to protect it from strikes on the trail. When the derailleur takes a hard knock – like when smashed against a rock – the overload clutch pulls it inward and away from the obstacle so that you don’t damage it or bend your hanger.
Another benefit of the AXS system is the gears never go out of sync. Never ever. The cable-free setup means less rattling and makes for a cleaner cockpit too. I really like the fact that shifting is effortless, as it does matter when the heart rate is high. Throughout the test, I could only imagine two reasons not to upgrade. One would be the 40g extra weight over the non-AXS GX system. Another might be that charging of batteries is another item you’d rather not add to your pre-ride checklist.
I’m all for any technology that improves my riding experience. The performance of GX AXS does just that. In addition, the stamped steel cage and overload clutch will save the derailleur when sh*t happens. I’ve heard the upgrade kit works with other brand drivetrain systems – although this is something I never tried. Overall, the system is easy to live with and adds to the ride experience for cross-country, trail, enduro or eMTB riding.
| IMAGES: Gary Perkin | TRAIL: Missing Link, Camps Bay, Cape Town |