Absolute Black Derailleur Pulley | Hollowcage Carbon-Ceramic OSPW Ultegra 8150 12-Speed

The New Era of Silent Pulleys. Meet the Silent Xring Pulley™
Does it bother you when you ride in quiet scenery, but you can still hear your bike's chain engaging the pulleys? This familiar clunking noise has accompanied us on every ride for decades, and it's time for a change.

Standard polymer pulleys are fairly loud, which has always been the norm. Aluminum pulleys are even worse as the material radiates the sound more than any polymer, making them louder. We are introducing a new generation of pulleys, which can reduce the sound level by 5-7dB compared to stock Ultegra pulleys. This corresponds to roughly 40% of the noise reduction. Practically speaking, the cage becomes very silent.

We use a pending patent solution, our unique xring rubber suspended bands, that dampen the chain impact on the guide pulley teeth, eliminating the engagement noise, the single most significant contributor to overall drivetrain noise. From now on, your ride will be more silent than it used to be, and you will hear sounds you haven't noticed before. It's the new era of derailleur cages.

Why Is Our Ospw Hollowcage® so Special?

• *It is super silent (over 5dB noise reduction vs. stock).
• *The shifting is as good as with the original Dura Ace cage.
• *One of the lightest oversized cages on the market.
• *First mono plate construction of its kind.

Our bearings are full ceramic. In technical terminology, it is a bearing with inner and outer race and balls made of ceramic material. The seals and the cage, however, are made of polymer. Other common types of bearings are steel bearings and hybrid bearings. The latter is often mistakenly called a "ceramic" bearing, but only the balls are ceramic. Races are still made of steel. Hence there is a term "full ceramic," indicating that not only the balls are made of ceramic but both races too. Our bearing races are made of 100% Zirconia Oxide ceramic, and balls are made of Silicon Nitride ceramic. The cage and seals are, of course, made of low-friction polymer.

How to Mount Hollowcage

Please refer to the video instruction below. For Sub Compact (<34/50t) and Compact (34/50t) chainring combinations, you can use the lowest spring tension setting (First hole from left). However, If you ride on roads with potholes, cobbles, etc., it is recommended to set the HOLLOWcage to high spring tension (First hole from right). Use a high spring tension setting if you have a 52t chainring or more significant.

Designed in England. Manufactured in the EU. The World's best-oversized derailleur pulley cage.

Specifications

• Size (Mass +/-1g): 71g
• Color Lower lockring: PVD Rainbow, Black, Titanium, Red, Gold; Upper lockring: Black
• Compatibility: Shimano Ultegra 8150 12spd ONLY. Fits up to a 34T cassette.
• Materials used: Carbon fiber-polymer matrix, 7075 Aluminium, rubber, ceramics
• In the box Complete cage, lockring tool, 2x spare xring rubbers.

SKU# TCRCAGEU81/BK-RD_Std