AbsoluteBlack has today unveiled HollowCage, its entry into the market for large step wheel systems.
A 71-gram HollowCage stands out from conventional designs by virtue of its large hollow center to the lower pulley wheel, with bold claims around performance.
It will compete with products such as Kogels Kollossos, Muc-Offs LOPS and Token’s Shuriken, as well as the market-leading OSPW from CeramicSpeed. While the hollow design has been done before – by Joshua Ogle from oglomponentdesign – AbsoluteBlacks HollowCage is the first of the largest brands to use this concept.
It is constructed using a number of patent pending designs. The first is a mono-plate carbon cage that avoids the traditional two-sided design in favor of a single-plate carbon polymer that hoses from the left side of the upper pulley, down and out to complete on the right side of the lower pulley.
The other comes in the form of a ‘Silent XRing Pulley’, which AbsoluteBlack claims enables a reduction in noise of 12-14dB compared to stock Dura-Ace pulleys, thanks to what it calls ‘xring rubber-hanging straps’, which dampen shocks between the chain and the teeth of the step wheel.
According to the brand, HollowCage will now be almost silent in operation, while still maintaining changing performance on a par with Shimano’s OEM Dura-Ace.
To achieve this, AbsoluteBlack claims that it has moved stiffness from the cage to the upper pulley, and adds high teeth to the upper pulley to improve displacement accuracy.
“It is the upper pulley that moves the chain to the left and right, so that the gear can be shifted, so making the upper pulley very stiff gives greater shifting precision,” states AbsoluteBlack. “HollowCage, unlike other pulley systems, uses abnormally large, bespoke, full ceramic bearings that make the pulleys incredibly rigid.”
To add to this, AbsoluteBlack claims that the monoplate cage provides flexibility in the cage itself, which makes it possible to better adapt to the chain lines, which further improves the system’s efficiency. AbsoluteBlack actually believes that HollowCage will save more watts overall than any other cage on the market. The monoplate construction itself is constructed of a carbon polymer material and is covered in pits to aid in aerodynamics.
However, it is not aerodynamics, chain line optimization or even the ceramic bearing quality where the bulk of HollowCage’s performance gains were found. According to AbsoluteBlack, it comes from spring tension.
“There is a linear correlation between spring tension and power loss generated by the cage,” the company claims. “HollowCage uses lower spring tension than any other cage on the market, while providing excellent shifting thanks to the unique combination of step stiffness and high teeth.”
Not surprisingly, it is not cheap, and is launching today with a retail price of £ 519.00, available at AbsoluteBlack.cc.