First Impression – SRAM Eagle Transmission Electronic Drivetrain

SRAM Eagle Transmission is a radically robust, fully integrated, interdependent wireless transmission. It uses no derailleur hanger or adjustment screws and lets you shift flawlessly under maximum power. All the Eagle Transmission components use the T-Type designation. If it’s marked T-Type, it’s compatible with all the Eagle Transmission T-Type parts, allowing you to mix and match between the groups. It is only compatible with UDH bikes.

It currently comes in a XO ($1599), XX ($2099-$2299), and XX SL ($2199-2699) version.

We got to do a short test ride and see the drivetrain up close at a Criterium Bike Shop and SRAM MTB presentation in Colorado Springs. See our ride impressions at the bottom of the post.

UDH and Full Mount

It utilizes the Universal Derailleur Hanger (UDH), and the Hangerless Interface allows Eagle Transmission to work around the one universal constant – the center of the rear axle. Utilizing the larger diameter of the Hangerless Interface, Eagle Transmission mounts to your bike with a super strong, super simple Full Mount design. Full Mount literally clamps around both sides of the frame itself and eliminates the need for a hanger. This super-strong connection eliminates variance and improper adjustment across frame designs. It also eliminates hanger failures and allows the derailleur to rotate backward in case of an impact.

Currently, there are 210 UDH bike models available and counting.

AXS Derailleur

No more B-screw or high and low adjustments are required!

Engineered as integrated, interdependent transmission components, the T-Type derailleur mounts around the wheel axle itself, contacting the cassette directly with a first-of-its-kind Hangerless Interface. The new Transmission derailleurs feature the same intuitive pairing and setup procedure as our Eagle AXS derailleurs, and it features an overload clutch and a tucked-in profile.

The derailleur houses its pulley wheels in what they call their Inline Cage, and it’s oriented to keep the top pulley in perfect alignment with the cassette throughout the entire gear sweep and keeps the bottom pulley at an optimum angle with the front chainring, all for superior chain management and better longevity. This design provides noise reduction, smoother running, chain management, and better longevity. The 14-tooth oversized bottom pulley in the Inline Cage is called the Magic Wheel because its outer ring rotates independently from the inner spoked hub. Magic Wheel takes over should a stick become lodged between the pulley and cage, and your chain can continue threading through the derailleur without a damaging jam or bind.

The significant differences between the XO, XX, and XX SL derailleurs are materials and the amount of finish work, primarily for weight-savings. The derailleur is mostly serviceable/rebuildable, with replicable parts and coverings.

Cassette

The cassette still uses SRAM MTB standard 10-52t range, but it gets improved gear progression with the 38 and 44 tooth cogs (instead of 36,42), making for steps of 10,12,14,16,18,21,24,28,32,38,44,52. The cassettes use narrow-wide X-Sync profiles, along with well-defined ramps and shaping. The shift ramps have been redesigned for improved inboard and outboard shifting performance under load, chain retention, and engagement. The one odd cog is their “setup” gear which is indicated by a red plastic insert, and it’s used during their system’s initial installation.

The XO and XX use hardened tool steel machined X-Dome design for the cluster, and stamped steel 38T and 44T cogs are pinned to the lighter weight aluminum 12th gear. The XX SL uses hardened steel X-Dome architecture for gears 1-9 and an ultra-lightweight, all-aluminum Spider Cog for gears 10-12.

Chain

The Flattop mountain chains are their strongest chains ever. The upper Flattop profile, along with the smooth-shift bottom profile, offers the ultimate in-shifting performance. The XO has standard pins and plates, the XX gets hollow pins, and the XX SL gets hollow pins and cut-outs on the outer plates.

Crank

The cranks utilize a new 8-bolt direct-mount chainring interface instead of their current 3-bolt. The XO is an alloy crank, the XX is Carbon with a foam core, and the XX SL is Carbon with a hollow core. The XO and XX have integrated bash guards on the chainrings and are correctly positioned and removable. They also have power meter options.

AXS Pod

The Eagle Transmission AXS Pod Controllers are intuitive, discreet, and programmable. Mount on the left or right, or which button shifts up or which one shifts down; configure your way on the AXS app. The Infinity Clamp gives you infinite mounting configurations for ultimate freedom, with a flippable design and 360-degree adjustability at both the controller mount point and the handlebar. The standard Pod has fixed concave button pads, while the Deluxe version has removable buttons with both concave and convex pads.

First Ride Impressions

While I only got a brief period riding a bike with the new SRAM Eagle Transmission, it was a vast eye-opening, and enriching experience. I got to place the drivetrain under a significant load going up a steep hill and pulling a weighted sled (that was pretty cool).

The new SRAM Eagle Transmission wireless electronic drivetrain is a wonder to ride, making cable-operated systems seem quaint. The Transmission is an entirely different beast than all cable and electronic systems (including their own), and this technology is truly unique and highly engineered. It offers quick and consistent shifting, and once set up; it requires no further adjustments. Under any heavy load, the action was buttery smooth and precise, though it did seem a tad slower than the normal AXS (hardly notable). On typical terrain, it shifted effortlessly, lightly rolling through the gears. The drivetrain was quiet, and the newly designed cassette cog ramps, chain, and derailleur worked in synergy for a swift and smooth gear transition without any clunking or hesitance, quickly and effectively moving from cog to cog. It was the first time I felt that SRAM had matched the highly engineered work of art ramping and shifting capabilities on the Shimano cassettes. The Pod offered crispy clicks as the system shifted gears.

The derailleur design means it can take some abuse (not tested), and it is serviceable with replaceable parts.

Some other highlights of the SRAM Eagle Transmission:

• Wireless transmission
• Full Mount design – due to Universal Derailleur Hanger and the Hangerless Interface
• Fully integrated T-Type system
• Simple and quick setup; no further adjustment required
• Derailleur – Inline Cage and Magic Wheel
• Configurable AXS Pod

The only bummers are the entry price and that it only works on UDH bikes. Want!