SRAM GX Eagle Transmission groupset – Entry-level direct mount drivetrain in review
Goodbye derailleur hanger, hello direct-mount! After introducing the flagship models of their all-new Transmission groupsets, SRAM now present the new, more affordable GX Eagle AXS Transmission, which will be the most interesting option in the hangerless Transmission Type ecosystem for most riders. Read on to find out how the new groupset differs from its high-end counterparts, and what makes the € 1,300 GX Eagle Transmission even better.
Ever since mountain bikes have had derailleurs, companies haven’t stopped developing and improving them. The gear range has increased, the gear steps have been optimised, and with SRAM AXS and Shimano Di2, derailleurs have gone electric. The problem is that the more gears you have on the cassette, the more precise the adjustments must be. And the more important maintenance and care becomes. But manufacturing tolerances between the frame, derailleur hanger, and the derailleur are also partly responsible for inconsistent shifting performance and having to fiddle with the setup.
With the recently introduced SRAM X0 and XX Eagle Transmission groupsets, the tolerances and thereby the required adjustments could be reduced to a minimum. And now the new GX Eagle Transmission groupset has entered the Transmisison Type, or T-Type, cosmos – which is battery operated and relies on the wireless AXS protocol throughout.
Wait, what?! Another standard? No worries, though. You will have noticed that a big chunk of bike frames on the market use the universal SRAM UDH derailleur hanger, allowing the derailleur to be mounted directly to the frame, or rather the rear axle. So, if your bike has a SRAM UDH hanger, you’re good to go – your frame is compatible with the T-Type standard. The new GX Eagle Transmission groupset takes advantage of the same benefits as the higher end X0 and XX Eagle Transmission groupsets, and even builds on them. But does the new kid on the block also have drawbacks compared to the more expensive variants? We’ve got all the details, prices, and a first ride review.
Back to the future – What distinguishes the GX Eagle Transmission from the X0 and XX Eagle Transmission groupsets?
The new principle of the Transmission groupsets has now trickled down to the GX level. The GX Eagle Tarnsmission offers the same advantages as its more expensive siblings:
- a direct-mount frame interface = so no more derailleur hanger,
- no B screw to adjust, and
- no upper and lower limiting screws.
This minimises the adjustment options and reduces potential error sources.
What are the differences between the GX and the XX/X0 T-Type derailleurs?
So, how does the GX T-Type derailleur differ from the XX/X0 models? With the XX and X0 T-Type derailleurs, the upper bracket, which is the part that wraps around the axle and the frame and thereby replaces the UDH (Universal Derailleur Hanger), is machined from aluminium. On the more affordable GX model, the upper bracket consists of individual aluminium parts that are screwed together. Whether this makes this assembly less durable will only be revealed by long-term tests. Nevertheless, the GX T-Type derailleur makes an extremely solid impression, and the lower production costs are passed on to the buyers, which we’ve come to expect from a GX level drivetrain.
That said, the GX T-Type derailleur has a big advantage concerning the position of the battery, seemingly already boasting the next evolutionary stage of the SRAM Transmission line-up. The battery is no longer exposed at the rear of the derailleur but is now located between the axle and the derailleur.
The battery is securely embedded, making it virtually impossible for you to slam the battery into something and lose it. Moreover, the clip for attaching the AXS battery is replaceable in case it breaks – brilliant!! We wonder if this design will also be adopted by the flagship models in the future.
Differences and similarities of the SRAM GX and XX/X0 T-Type cassettes
The cassettes of the new SRAM GX Eagle Transmission, and the more expensive X0 and XX Eagle Transmission groupsets all have 12 gears, though they rely on a different manufacturing process. Just like the upper bracket, which is machined on the flagship models, the nine smallest gears of the XX and X0 cassettes are machined from a single block of steel. Gears 10 and 11 are stamped out of steel and riveted together, and the easiest gear, number 12 is made of aluminium. In the case of the SRAM GX Transmission cassette, the 11 smallest sprockets are made of stamped steel and riveted together to reduce costs.
Only the easiest, 52 t cog is the same as its higher-priced siblings and made of aluminium. The only noticeable difference is the weight, as the gear steps and 520% range remain the same. As with the XX and X0 T-Type cassettes, in the GX Eagle T-Type cassette cogs 10 and 11 now have 38 and 44 teeth respectively, which is two teeth more than non-T-Type cassettes, optimising the gear steps of the three easiest gears.
The chain of the new SRAM GX Transmission groupset
Like the other SRAM Transmission groupsets, the new GX T-Type comes with a Flattop chain. These chains have been adopted from the road segment and are flattened on the top, so they can only be fitted in one direction. You’ll also need a special quick link, of course, as it’s incompatible with non-Flattop quick links.
To fit the chain, it must be shortened to an exact number of links. This depends on the chainstay length, and the exact number can be found in the setup guide of the SRAM AXS app. The proper chain length is essential to get optimal shifting performance.
The cranks of the SRAM GX Transmission groupset
The cranks of the new SRAM GX Transmission groupset feature a new shape, which is very similar to the aluminium X0 T-Type cranks. The GX T-Type cranks are made of forged aluminium and have an upper and lower bash guard. You can keep both bash guards or you can remove them independently of each other, depending on which foot you keep forward, determining which section of the chainring needs protection.
The eMTB specific cranks are available in 160, 165 and 170 mm lengths. They’re kept short since the motor makes up for the reduction in leverage, which reduces the likelihood of getting hung up on the pedals. The MTB cranks will be available in lengths of 165, 170 and 175 mm – up to 5 mm longer than the eMTB-specific version. With analogue bikes the leverage matters more, of course, as it contributes significantly to the amount of power you can generate.
The controllers of the new SRAM GX Transmission
If you order the complete SRAM GX Transmission groupset, you will also receive the new controller from SRAM – the so-called Pod. With the two buttons arranged vertically, it provides a digital feel that no longer has much in common with a mechanical trigger.
Unlike the Ultimate Pod used on the high-end groupsets, the GX Pod isn’t silver, and the buttons aren’t rubberised. It’s got a premium shifting feel and the buttons provide noticeably more feedback than the old AXS controllers. The buttons can also be attached in almost any configuration thanks to the Infinity clamp, which resembles the infinity symbol. However, the new GX Eagle Transmission can be connected and used with any controller from the SRAM AXS ecosystem – in case you miss the feeling of a classic trigger.
The price and weight of the new SRAM GX Eagle Transmission
SRAM’s recommended retail price for the GX Eagle Transmission is € 1,300 .This is for the complete package, including the cassette, chain, chainring, quick link, crankset, derailleur, and controller. Compared to the SRAM X0, XX and XX SL T-Type groupsets starting at € 1,900 and going up to € 3,250 (including the power metre), this already represents a significant price drop.
Price list:
- Groupset € 1.300
- Derailleur € 480
- Cassette € 300
- Crankset with chainring € 240
- Chain € 60
- Chainring € 47
For the eMTB specific groupset, SRAM are asking € 1,250 of Bosch and Brose riders. For models on which the cranks are incompatible, the groupset can be bought without crank arms for € 1,150.
It should be noted that these are just the recommended retail prices and the prices of the first Transmission models have already been reduced by up to 30% three months after launch. So, if you’re patient, you’ll likely be able to get your hands on the new GX Eagle Transmission even more affordably. ;)
The weight of the complete GX Eagle Transmission is 2,020 g. Compared to the XX and X0 T-Type groupsets we’ve tested, this is a weight penalty of just 140 to 300 g.
- 170 mm crankset with both bash guards and 32 t chainring 733g
- Derailleur (incl. battery) 487 g
- Pod (incl. clamp) 71 g
- Cassette 440 g
By the way, if you’re in the gram counting game, you can save the most weight with the higher-end XX cassette (60 g) and the XX carbon cranks (138 g).
Our first ride review of the new SRAM GX Eagle Transmission
We tested the new SRAM GX Eagle Transmission on an eMTB as well as an analogue mountain bike. We didn’t notice the added weight compared to the previous non-Transmission SRAM groupset. The weight of two bars of chocolate or a half-filled water bottle are an acceptable price to pay for the increased shifting performance.
With the new GX T-Type groupset, you also get a significantly cleaner looking bike: due to the changed battery position, the rear derailleur seems more compact and doesn’t stick out as much. The black finish further helps the compact look. The new battery position also means it’s almost impossible to lose, yet replacing it remains easy: simply insert the battery between the axle and the derailleur and lock it in place with the clip. Following our SRAM Eagle Transmission installation guide, the initial fitment of the derailleur was easy, after which we only had to fine tune the alignment by three clicks using the MicroAdjust function – and we were all set.
That’s it for the installation, but how does the new GX Eagle Transmission perform on the trail? The shifting feels very similar to the flagship SRAM X0 and XX Eagle Transmission groupsets we’ve tested before. Although the individual shifts are somewhat slower, they’re more precise and feel significantly “softer” compared to a conventional derailleur. You can shift easily even under a heavy load, and it won’t sound like your chain is about to rip apart. About one in every ten shifts is noticeably louder, but you’ll hardly hear it the other 9 times, and it’s always smoother than non-Transmission drivetrains. When shifting, the derailleur waits for a shifting ramp on the cassette instead of simply forcing the chain up the cogs. This is intended to reduce wear on the chain and avoid potentially breaking it due to lateral loads.
If you shift many gears at once, however, it can happen that the derailleur shifts another gear when you no longer expect it. This delay is further enhanced by the fact that the chain doesn’t skip any cogs, moving from one to the next in succession. On the bigger cogs, i.e. easier gears, this delay can be more pronounced than in the harder gears. That’s because the cogs of harder gears have a smaller circumference, meaning the chain needn’t travel as far. The GX Eagle Transmission significantly reduces your fear of breaking the chain, especially on an ebike, even encouraging you to make the occasional shift under load on a technical climb.
Our conclusion on the new SRAM Eagle Transmission groupset
The new SRAM GX transmission left a positive impression throughout. It’s more affordable than its premium siblings, has a more refined and secure battery port, and offers nearly the same shifting performance. The only drawback is the slightly higher weight. For us, the advantages easily outweigh this. It may not be the right choice for weight fetishists that count every gram. However, all those who are looking for a good combination of durability, performance, affordability will get their money’s worth with the GX Eagle Transmission.
For more information, visit sram.com
