HOLLOWcage has a carbon-polymer mono-plate construction with bespoke, oversized, full ceramic bearings and advanced silencing pulleys
Special xring rubber suspended bands dampen the chain impact on the guide pulley teeth, therefore eliminating the engagement noise, which is the single biggest contributor to overall drivetrain noise (over 12dB noise reduction vs stock)
The shifting is as good as with the original Dura Ace cage. Abnormally large, bespoke, full ceramic bearings make the pulleys incredibly stiff and very tall teeth of the upper pulley gives the best possible shifting precision
The mono plate cage can dynamically adapt to the chain angle as it allows the cage (and therefore lower pulley) to align better with the angle of the chain when using the higher gears of the cassette. This means less friction (and less watts lost) as the pulley doesn’t have to fight against the chain itself
Adjustable spring tension lets you adjust for cassette size and chain length to find the lowest possible tension (and lowest watts lost) for your needs
Compatible with Shimano 12 speed Dura Ace 9250 ONLY. Fits up to 34T cassette