SRAM RED XPLR: Why This Drivetrain Is a Game Changer

The cycling world is buzzing with the announcement of the new SRAM RED XPLR 13-speed groupset. Combining innovation and performance, this drivetrain marks a turning point in the world of gravel bikes, and soon, road bikes. More than just an addition to the existing range, the SRAM RED XPLR promises to redefine the standards, its gear range, and its modularity. In this article, we explore why this new drivetrain is a true stroke of genius and how it could transform your cycling experience.

A Significant Turning Point in Bicycle Drivetrains.

At CYKL, we believe the new SRAM RED XPLR system marks a significant shift in bicycle drivetrains. While 13-speed drivetrains have been on the market for some time, with Rotor pioneering and Campagnolo following suit with its gravel-specific Ekar groupset, SRAM's entry into the field is a game-changer. The configurations available with this type of drivetrain allow the majority of road cyclists and touring cyclists to ditch the front derailleur once and for all.

This article is not a simple review or technical description of the new transmission, but an in-depth reflection on the evolution of bicycle transmissions, present and future.

As a reminder, the SRAM RED XPLR AXS drivetrain announced in recent days is the gravel version of the latest RED AXS road drivetrain, launched earlier this year. This new groupset further elevates the XPLR range, initially introduced in 2021, and designed as a bridge between SRAM's MTB and road ranges. It brings the worlds of road and MTB even closer together, offering unprecedented flexibility. Beyond the 13-speed cassette, the derailleur has the particularity of using the T-TYPE or full mount standard. (more details later) For us, it is obvious that the T-TYPE rear derailleur mounting system will eventually be deployed in the coming years on all types of bikes. It remains to be seen how other brands will react to this new standard.

At CYKL, we anticipated this evolution. All our bikes, including our road models, are compatible with this new groupset. Thanks to the adoption of the UDH standard and the development of T-TYPE technology, our bikes are compatible with all drivetrains on the market, as well as T-TYPE.

Unlike Shimano, which offers specific groupsets for gravel with its GRX range, SRAM offers unparalleled flexibility. Want a double crankset? Choose from the road catalog. Prefer the simplicity of a single chainring with a wide range of uses? The options in the mountain bike catalog are there for you. This flexible approach allows for numerous hybrid builds, combining components from different worlds.

The new Red XPLR AXS adds a new dimension to all these possibilities, while remaining compatible with many existing products. We took the time to write this in-depth article to explain why this 13-speed drivetrain with a 10-46T cassette is a revolution for most road and gravel uses. You'll also discover why the double chainring is doomed and why SRAM's standardization strategy is a stroke of genius.

Why a 13-Speed ​​Drivetrain with a 10-46T Cassette Meets Most Road and Gravel Uses?

To understand the principle of a transmission, it is essential to consider three key factors: the speed range, the gear spacing and the size of the chainring.

The Amplitude of Speeds

The gear range, expressed as a percentage, indicates the range of available gears. It varies depending on the terrain: a flat region requires a small range, while a mountainous region requires a large one. This range is mainly determined by the cassette size. For example, on a 2x12 drivetrain with a 10-30T cassette, the range is 441%. In comparison, a 10-46T cassette offers a range of 460%, surpassing even double-chainring setups. Here's an overview of the ranges of the different cassettes:

• 10-44T Cassette: 440%
• 10-46T Cassette: 460%
• 10-50T cassette: 500%
• 10-52T Cassette: 520%

Thus, a 10-46T cassette offers a greater amplitude than a double chainring.

Speed ​​Gap

To determine the spacing, the amplitude will be divided by the number of gears. But this gap is not uniform across the entire amplitude. The first gears have a greater gap than the last five gears.

In theory, a 2x12 drivetrain offers 24 gear combinations (2 chainrings x 12 sprockets), but in reality, the number of usable gears is between 16 and 18, due to overlap and inefficient combinations caused by chain crossing. With a 13-speed drivetrain, the gear spacing is optimized, providing a smooth and continuous progression of gears. For example, a 10-46T cassette with a gear spacing of 10, 11, 12, 13, 15, 17, 19, 21, 24, 28, 32, 38, 46 offers similar spacing to a double chainring, with the added benefit of reduced overlap.

The Size of the Plateau

The chainring size should be chosen based on your muscular capacity and the desired maximum speed, maintaining a pedaling cadence between 80 and 95 RPM. A larger chainring allows you to ride faster, but requires more effort, especially when climbing. It is therefore crucial to choose a chainring adapted to maximize the efficiency of the intermediate gears, staying as much as possible on the 11th, 12th, 13th, and 15th gears of the cassette for optimal chain alignment.

Other Factors to Consider

A single-chainring drivetrain is simpler to use, faster when shifting, more reliable thanks to fewer parts, and lighter. All of these advantages make a 13-speed drivetrain with a 10-46T cassette an ideal setup for a wide range of uses, from all-road/endurance road bikes to XC or trail mountain bikes. With a wide variety of chainring sizes available from SRAM and other manufacturers, it's possible to optimally match the drivetrain to each rider.

Other Reasons for the Success of this Transmission

Two key elements of the new SRAM drivetrains deserve special attention: the UDH derailleur hanger and the T-TYPE or full mount derailleurs.

The UDH Derailleur Hanger

SRAM initiated one of the most significant evolutions in bicycle drivetrains with the Universal Derailleur Hanger (UDH). Even before the introduction of the SRAM RED XPLR gravel group, SRAM had a long-term strategy in place. The often-overlooked derailleur hanger became a revolutionary element.

Traditionally, the derailleur hanger is a sacrificial part connecting the rear derailleur to the frame, designed to bend or break upon impact, protecting both the derailleur and frame. For years, each frame had its own specific hanger, complicating replacements. In 2019, SRAM launched the Universal Derailleur Hanger (UDH) standard, unifying the standards and simplifying replacements. The UDH, consisting of the hanger itself and the "UDH bolt," is an open, unlicensed standard adopted by many brands. It is compatible with derailleurs from various brands, including Shimano, Campagnolo, and TRP.

This standardization not only facilitates replacements, but also improves structural integrity and optimizes shifting. The UDH thus paved the way for SRAM's new mounting system, the full mount.

T-TYPE or Full Mount Derailleurs

SRAM discovered that more than half of all drivetrain issues were related to the derailleur hanger and traditional rear derailleurs. The T-TYPE drivetrain project aimed to eliminate these variations. By eliminating all adjustment screws, SRAM simplified installation and significantly reduced issues.

The UDH derailleur hanger is designed to absorb shock by pivoting rearward or sliding slightly to absorb an impact. If it pivots, it can be pushed forward without loosening the thru axle. It also features a hooked lip to reposition the chain on the smallest cog in the cassette in the event of a derailment.

The derailleur and hanger design has been redesigned for a coaxial connection with the frame, eliminating the B-bolt and other adjustment screws. The upper pulley now rotates around the cassette with a constant gap, improving shifting performance. SRAM has also developed an inline cage with a curvature for better tire clearance, ensuring that the upper pulley remains aligned with the cassette.

With this design, SRAM was able to specify the exact range of motion needed, eliminating traditional stop screws. The rear derailleur features a contact point with the cassette to prevent derailment in the spokes, and an internal stopping point to prevent the chain from falling between the cassette and the frame.

The new interface, directly connected to the thru-axle, makes the derailleur much more resistant to lateral and frontal impacts, transferring less crash energy directly into the frame. The integrated overload clutch allows the derailleur to fold in the event of a strong hit or when the axle is released. This innovative design works with all bike designs, including split-pivot, and frame clearance specifications are available to frame designers.