absoluteBlack HOLLOWcage® DuraAce 9250 Carbon Ceramic Oversized Derailleur Pulley Cage | Rainbow

absoluteBlack HOLLOWcage® DuraAce 9250 Carbon Ceramic Oversized Derailleur Pulley Cage | Rainbow

HOLLOWcage® for Shimano Dura ace 9200 12spd. Our revolutionary mono-plate OSPW design is the quietest and best shifting, oversized derailleur cage for Shimano 12spd created to date. HOLLOWcage ® OSPW has a carbon-polymer mono-plate construction with bespoke, oversized, full ceramic bearings and the most advanced silencing pulleys ever made.

Features

• Area of intended use : road, triathlon
  
• Material Cage: Carbon fiber-polymer matrix
• Material wheels: plastic, rubber
• Bearing: ceramic
• Number of teeth: 12 (top) 18 (bottom)
• Compatibility: Shimano Dura Ace 9250
• largest sprocket: 34 teeth
• Colour: PVD rainbow, black, titanium, gold or red
• Weight according to the manufacturer: 71g (+/- 1g)
• Weight weighed: 69g
  

Why is 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.

The new era of silent pulleys meet the silent XRING Pulley

Does it bother you when you ride in a really quiet scenery but you can still hear your bike’s chain engaging the pulleys? This familiar clunking noise has been accompanying us on every ride for decades. It’s time for a change.

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

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

Stiff roll
The popular belief is that a stiff cage equals good shifting. But if you take a close look at how the derailleur gears work, it quickly becomes apparent that the shifting precision depends largely on the upper roller. Since the upper roller is installed directly in the pivot point, the rigidity of the cage hardly plays a role in shifting precision. Rather, a stiff bearing of the roller is crucial. In contrast to other manufacturers, Absolute Black uses oversized bearings to reduce the lateral play of the wheels to a minimum and thus increase shifting performance.

Flexible cage
The construction of the cage allows for some alignment of the lower roller to keep the chain running as straight as possible. In addition to the smooth running of the chain, this special feature also reduces running noise.

X ring pulley
The patent-pending Xring-Pulley uses special rubber bands to reduce the noise of the chain by 12-14dB compared to the standard Dura Ace wheels. This corresponds to a noise reduction of about 60%.

High tooth profile
Some of the competitors use rollers with a very flat tooth profile in their oversized derailleur cages. However, a tooth that is too flat will never shift the chain to another gear as precisely as a tooth that is too high can. Absolute Black uses very high teeth on the upper roller of the hollowcage for exactly this reason. In conjunction with the large and stiff bearing , this results in the best possible shifting performance.

The game with the watt saving
There are many variables that can contribute to saving a watt or two. Lightly greased full ceramic bearings are used in the hollow cage for maximum service life. Thanks to the high tooth profile, the system manages with little cage tension and still shifts extremely precisely. The aligning lower roller also saves some power because the friction in the chain run is minimized.

The cage fits Dura Ace R9250 rear derailleurs.