SRAM

Red WiFLi Rear Derailleur - Medium

Gone are the days of mixing groupset tiers in order to accommodate your L'Angliru-esque climbing cassettes. With SRAM's introduction of the Red WiFLi Rear Derailleur, you now have the option of running cassette gearing as high as a 32-tooth cog. The result is a new range of gears that're wider than the standard triple chainring system, which, besides keeping your drivetrain clutter-free up front, also saves well over 250 grams. This means that when your big climbing days loom ahead, simply throw on a big cassette and stop fretting about whether your standard chainrings were the best choice after all. Of course they were.

When SRAM first introduced its groundbreaking 10-speed Red component group, the heart of the industry-shaking design was its 1:1 Exact Actuation technology. In ordinary terms, this means that with each shift, the derailleur pulls the same exact length of cable, regardless of what gear you're in. 1:1 is simple to set up, it stays in position longer, and it provides laser-accurate shifting. This advancement sent competitors scrambling to one-up SRAM -- cranking it to 11 or going electric. SRAM's engineers didn't buy the hype, and instead of 'me too-ing,' SRAM put massive efforts into improving its 10-speed drivetrain. The result is that the Red WiFLi benefits more directly from the lessons learned over the life of the first generation 1:1 than if SRAM were to start from scratch.

The Red WiFLi now has an air-cheating, low-profile mounting bolt that's made of titanium in order to keep weight as low as possible. Varying slightly from SRAM's Red Aero Glide Rear Derailleur, WiFLi lengthens its cage and gets a subtle variation in geometry in order to accommodate an 11-32 cassette. Additionally, it has ample chain wrap capacity in order to handle any SRAM crankset/cassette combination. The WiFLi's long upper-knuckle is still made of flex-resistant forged aluminum, which helps to maintain a perfect gear alignment. The inner-carbon fiber pulley plate has also been enhanced as to resist flex. Accordingly, the new design increases rigidity, providing more precise gear changes as its low weight results in a light action.

SRAM continues to run its Black Box ceramic cartridge bearings in the pulleys. Ceramic bearings provide higher durability and roundness in comparison to steel, which reduces mechanical drag by a substantial amount. After all, after aerodynamic drag, mechanical drag is the leading source of power loss.

The pulleys themselves were a focus area for SRAM engineers, and they improved weight, durability, and operation. Coined AeroGlide, SRAM optimized the jockey wheel's profile so that the chain will glide more efficiently over the tooth profile as it threads through the cage. This helped silence a notably noisy drivetrain, while also enhancing chain movement across the cassette. With those advancements, most would call it a day and skip out for an early ride, but SRAM's R&D team developed an elastomer coating to further quell pulley noise.

The SRAM Red Rear Derailleur WiFLi also receives a barrel adjuster for simple fine tuning, and because it continues to use Exact Actuation technology, it's compatible with all SRAM shift levers: Red, Force, Rival, and Apex.