SRAM revolutionizes downhill: the XX DH electronic transmission arrives along with the new Maven brakes and the 2027 BoXXer fork

SRAM takes a decisive step in modern DH with the launch of its first electronic transmission specifically for downhill. The new XX DH Transmission introduces the AXS ecosystem into the most extreme discipline of MTB and does so with a radical proposal: shifting under full load, a no-hanger architecture, and a 7-speed cassette optimized exclusively for competition.

Alongside it, the new generation of Maven brakes and the revamped RockShox BoXXer arrive, completing a gravity package designed as a system.

XX DH Transmission: the first AXS specific for Downhill

The XX DH Transmission marks the official arrival of the AXS electronic shifting system to DH. It is not an adaptation of the Eagle Transmission, but a specific 7-speed system created for the real demands of a World Cup DH descent.

RECOMENDADO

Wout van Aert returns to competition in the Omloop Het Nieuwsblad

How Evenepoel's position has changed to dominate time trials

Most professional cyclists would agree to limit the development of the transmission

The Cannondale Factory Racing storms the Gobik offices to present its new kit

Are we facing a new version of Tom Pidcock?: power, race reading, and general ambition

The Cape Epic 2026 is left without a rainbow jersey, an accident with a car door leaves Keegan Swenson injured

The system has been designed to allow shifts at full power without loss of transmission, something especially critical in explosive starts and final sprints.

Shifting under load without power loss

The core of the system is the Cassette Mapping concept, a shifting sequence managed by AXS firmware that maintains continuous engagement of the chain during the transition between cogs. In a context where riders may be applying powers comparable to an E-MTB at the start ramp, avoiding micro-cuts in force can mean differences of hundredths.

The cassette is specific to DH:

• 7 speeds
• 10-24T development
• Full X-SYNC profile
• Compatible only with T-Type chain

Available in traditional XD version or in the new XD SLIM standard, which allows for a more symmetrical spoke angle in 148 mm hubs, improving balanced wheel tension.

Full Mount and no-hanger architecture

The rear derailleur adopts the UDH interface and Full Mount fixation, directly embracing the frame and eliminating the conventional hanger. This solution, already seen in XCO for several years, is reinforced here with a specific construction for DH:

• Inline cage optimized for downhill
• Replaceable components (skid plates, outer link, and cage)
• Type 4 damper to reduce chain bounce

The most inward position of the derailleur, combined with the 148 mm standard, increases the clearance from the heel and protects the assembly in technical areas.

Specific DH cranks and compatibility with the Ochain system

The new XX DH cranks are machined in high-wear areas and are offered in progressively shorter lengths: 165, 160, 155, and 150 mm. They aim for greater ground clearance and fine-tuning of the center of mass.

The T-Type chainring for 56.5 mm chainline has been reinforced against impacts, and there is a 104 BCD version compatible with the Ochain system that eliminates pedal kickback.

AXS on the handlebar

The control of the transmission is handled by the AXS Pod Ultimate, with adjustable ergonomics and interchangeable buttons. The system completely eliminates wiring, simplifies installation, and reduces interference.

Weights and price of the new XX DH Transmission

In official figures, the XX DH Transmission declares 426 g for the AXS rear derailleur (€765), 701 g for the cranks (€490), and 150 g in XD version or 144 g in XD SLIM for the 10-24T 7-speed cassette (€545). The cranks are offered in lengths of 165, 160, 155, and 150 mm, with DUB DH (56.5 mm chainline) and DUB Wide (55 mm) options, while the cassette can be mounted on a standard XD hub or the new gravity-specific XD SLIM.

New Maven brakes: more modulable, same raw power

Along with the transmission, SRAM also updates its gravity brakes with the evolution of the Maven B1.

The brand maintains the maximum power that made the Maven one of the most powerful brakes on the market, but modifies the actuation curve of the SwingLink system to achieve a more progressive delivery in the first 25% of the lever's travel.

All B1 models now adopt:

• Four 18 mm pistons
• New optimized hydraulic ratio
• Better thermal management
• SRAM mineral oil

Available versions:

• Maven Ultimate: carbon lever and titanium hardware (363 g)
• Maven Silver: new forged machined lever (379 g)
• Maven Bronze (OEM): black finish and simplified architecture

Upgrade kits allow previous A1 models to adapt to the new SwingLink B1 architecture without the need for bleeding.

New RockShox BoXXer 2027 fork: predictability as a goal

The RockShox BoXXer fork is a reference in DH, and its new version revolves around the concept of predictability.

The new BoXXer 2027 has been redesigned to gain speed, focusing on reducing unexpected variations in fork behavior. The idea is for the rider to maintain posture, vision, and precision in support at high speeds, which is key in current World Cup circuits.

The big change comes with the new LinearXL air system, an architecture that seeks a more linear and position-sensitive curve within the travel. Unlike traditional designs that are more sensitive to compression speed, LinearXL maintains a constant progression throughout the travel: initial sensitivity, firm support in the mid-zone, and control in the final stretch thanks to a specific hydraulic bottom-out system. To achieve this, RockShox has redesigned the assembly as a complete system, including the air volume of the lower legs.

In this sense, the BoXXer incorporates the AirAnnex system, which increases the air volume in the legs to reduce unwanted progression and sensitivity to speed. Additionally, strategically placed ventilation holes in the stanchions allow for internal pressure compensation as the fork works, reducing initial friction and improving sensitivity throughout the travel.

The Charger 3.2 cartridge has been readjusted specifically to work with LinearXL. It offers independent high and low-speed compression adjustment and maintains silent operation. Furthermore, the ButterCups technology remains a differentiating element, isolating the cartridge shaft and air spring to reduce high-frequency vibrations, with the brand claiming up to 20% less, which helps reduce arm fatigue on long and bumpy descents.

Structurally, the BoXXer maintains 38 mm stanchions and a chassis oriented towards precision in tracking without resorting to oversized components that generate parasitic vibrations. It also incorporates the ButterWagonTech system, a specific machining in the stanchions that distributes oil to the bushings during operation to maintain sensitivity throughout the maintenance interval. The seals developed with SKF aim to minimize deep friction in the travel.

The new BoXXer will be available in Ultimate and Select versions, with travel options of 180, 190, and 200 mm and compatibility with 27.5” and 29” wheels. The official price starts at €1,635 for the Select version and rises to €2,180 for the Ultimate.

A complete system for modern DH

With the XX DH Transmission, SRAM introduces for the first time a specific electronic group for Downhill. The combination with the new Maven B1 brakes and the 2026 BoXXer clearly points to an integrated system approach: transmission, braking, and suspension designed to work with greater control, less interference, and maximum robustness.

It is not just about eliminating cables, but redefining how power is managed, whether shifting gears, braking in support, or absorbing impacts in high-speed areas.