The most important facts in brief

Unfortunately, this means once again: a new technology and no compatibility with previous products. If you want to switch to a transmission rear derailleur, you first need a frame that is designed for UDH derailleur hangers. This is because they are mounted directly on the bike frame and not via the derailleur hanger. Due to the newly introduced T-type tooth profile of the drivetrain, the chain, chainring and cassette also need to be replaced. In addition, the "Eagle Transmission" requires special wide cranks with a 55 mm chainline. Now for the good news: If you have an AXS shifter, you can continue to use it. What's really great is that if the rear derailleur is defective, almost every component is available from specialist retailers or online stores.

First impression

The new design of the rear derailleur is solid and, according to Sram, should be able to withstand even major crashes and readjust itself so that the shifting process runs smoothly again. Compared to the top groupsets, the AXS battery of the GX is located inside the frame mount. This makes it seem impossible for it to fall out during use due to contact with the ground. The crank comes with two bolted-on bash guards and, like the derailleur, looks ready for the toughest applications. The Ultimate shifter, which is also new, is supplied with two differently shaped rubber pads that can be changed in seconds.

In use

Installation is a little more complicated than usual and requires a few more steps than with the previous AXS components. You can find good video instructions online, so it's not a big deal. Fine-tuning the gears with the app is done in record time. The only difficult part is finding out which spacer rings need to be fitted to the bottom bracket. Sram should provide better instructions for this.

After a few rides off-road, you'll be familiar with Transmission, as shifting itself hasn't been reinvented. Unfortunately, it's a little slower than with the classic AXS Eagle, but barely audible at low pedal pressure. The only thing that takes some getting used to is that you only shift one gear at a time. If you briefly press the shift lever three times, it takes three shifts to complete. Upshifting takes noticeably longer than downshifting. Under full load, the "teeth" occasionally grind, even if they are well oiled. Due to the high chain tension, the system makes no noise when riding downhill.

When there was actually a rock on the ideal line and the rear wheel didn't want to ride around it, the rear derailleur suffered a good knock. After a brief whirring noise, it readjusted itself and the ride continued. Cool, it seems that Transmission is really robust. Two weeks later, it bangs again, but only half as hard as the first time. The whirring stops and only 9 of 12 gears can be changed. The chain jumps around in three of them like children on the playground. Take out your cell phone, start the app and adjust the gears with the software while riding and you're back on the road. Cool once again!

There are now some transmission-compatible attachments from third-party manufacturers. For example, oval chainrings from Absoluteblack. Changing the chainring makes you shake your head again. It is mounted with no less than eight small Torx 20 screws. Another new standard, which also requires a tool that can only be found in well-stocked toolboxes.

Conclusion

Sram's "GX Eagle Transmission" leaves a mixed impression. The individual parts are significantly more robust, the function is top-notch, as is the self-adjustment. The fact that the groupset is not compatible with its predecessors is no joy. New standards such as the flat-top chain, the chainring mount and the fact that the rear derailleur cannot be mounted on many older bike frames are annoying. The somewhat slower shifting process will primarily upset racers and the impatient. To answer the initial question: Yes, the "GX Eagle Transmission" basically delivers what it promises, but it does not herald a new shifting era. Considering that the cable-operated GX groupset costs just half as much and is also durable and reliable, everyone has to decide for themselves whether the purchase is worthwhile. The new groupset is definitely not a bad buy.

Price: from CHF 1299 / EUR 1150.00

Recommendation

In order to install the transmission groupset correctly, some information about the bike is required. Sram even offers a bike brand guide, in which many models and their transmission presettings are stored. If you can't find what you're looking for there or if choosing the right spacers for the bottom bracket is driving you crazy, we recommend going to a specialist dealer. Otherwise, there is a risk that the drivetrain will not function correctly or may even be damaged.

Manufacturer

www.sram.com