absoluteBLACK confirms the availability of the HOLLOWcage V2 for Shimano Dura-Ace Di2 12-speed (R9250), an oversized derailleur cage that bets on a quieter drivetrain and lower friction. The price is €399, lower than the first generation which was around €499.
Below are the key technical features.
Mono-plate: one plate, controlled flex
The most striking thing about the HOLLOWcage is the single cage plate, instead of the usual two-plate sandwich design. That mono-plate is injection-moulded from a carbon-polymer matrix, the same type of material that SRAM used for RED eTap AXS cages.
The construction weighs only 66 g (+/- 1g) and offers controlled flex. This allows the lower wheel to align better in sloping chain lines, reducing side load on the bearings.
Smoother gear changing with Xring technology
absoluteBLACK claims that the Silent Xring Pulley™ reduces drive noise by 5-7 dB, equivalent to about 40% less chain ratchet. The technology is simple: rubber X-ring bands in the pulley absorb the impact of the chain rollers on the teeth. According to absoluteBLACK, especially noticeable on quiet endurance rides or indoors.
The top wheel (12T) is rigidly mounted for fast Di2 shifts. The lower wheel (18T) has the distinctive hollow design and is deliberately more flexible.
Full-ceramic bearings with certification
The bearings are fully ceramic: races of Zirconia Oxide and balls from Silicon Nitride. No hybrid variant, then. The composition has been independently verified by Lucideon Ltd via X-ray diffraction. absoluteBLACK gives there 4-year warranty on.
Specifications
- Weight: 66g (+/- 1g)
- Materials: carbon-polymer matrix, 7075 aluminium, ceramic, rubber
- Compatibility: exclusively Shimano Dura-Ace 9250 Di2 12-speed (max 34T cassette)
- Bearings: full-ceramic (Zirconia Oxide races, Silicon Nitride balls)
- Colour lockring: PVD Rainbow, Black, Titanium, Red, Gold
- In the box: complete cage assembly plus lockring tool
- Price: €399
absoluteBLACK claims no specific power gains. Developed for use with an R9250 groupset, the HOLLOWcage V2 aims for a quieter drive and a different design; with €399 the price is below that of the first generation.
More info at absoluteblack.cc.
