HOLLOWcage® for Shimano 9100 /
8000. Ourrevolutionary mono-plate OSPW design is the quietest, best
shifting,aerodynamic derailleur cage design created to date. It is a
dawn of new era forrear derailleurs. HOLLOWcage ® OSPW has a
carbon-polymer mono-plateconstruction with bespoke, oversized, full
ceramic bearings and the mostadvanced silencing pulleys ever created.
FLEXIBLE OSPW CAGE IS BETTER THAN ASTIFF ONE.
Contrary to common knowledge,
flexibilityis good as it allows the cage (and therefore lower pulley)
align better withthe angle of the chain when using the higher gears of
the cassette. This meansless friction (and less Watts lost) as the
pulley doesn’t have to fight againstthe chain itself. Shimano has
partially solved this issue by bending the lowerpart of the cage
slightly outwards, to align better with the chain when usingtop of the
cassette range. We have taken a different approach and eliminatedone
part of the cage all together, creating mono plate cage that
candynamically adapt to the chain angle.
STIFFER GUIDE PULLEY, NOT CAGE, MEANSBETTER SHIFTING.
Many companies try to convey
that a stiffercage is a better shifting cage. But the single most
important factor thatimpacts the shifting is the upper pulley itself.
Since the upper pulley ismounted directly to the rotating pivot axle,
the flexibility of the cage playsvery little role. It’s the upper pulley
that moves the chain left and right enablinggear change, so making the
upper pulley really stiff allows for greatershifting precision. Most
oversized pulley cage systems use very small bearings,with a lot of
lateral play at the teeth which in turn provide poor, sloppyshifting.
HOLLOWcage®, unlike other pulley cage systems, use abnormally
large,bespoke, full ceramic bearings that make the pulleys incredibly
stiff. Lowerbearing alone is actually big enough to fit 11T pulley
inside of it.
THE PROBLEM OF SHALLOW TEETH.
One of the main shifting issues,
apart frompulley stiffness alone, stems directly from the low teeth
profiles. Low teethsimply can’t move the chain effectively left or right
when you change gear.They are the only points of contact with the
chain, but for some bizarrereason, majority of oversized pulley systems
come with very shallow teethprofiles. This is the major contributing
factor to oversized pulley cagesshifting badly. HOLLOWcage® uses very
tall teeth of the upper pulley whichgives the best possible shifting
precision.
OVERSIZED CAGE IS ACTUALLY MOREAERO.
There is a general belief among
some of theriders that oversized cages are less aerodynamic. Their
larger surface area,when compared to OEM cages, must result in some
power losses, which wouldoffset the gains generated by the bigger
pulleys. We have tested the marketleading cage as well as original
Dura-Ace cage in a bespoke wind tunnel,designed for smaller objects.
HOLLOWcage® proved to be more aerodynamic thanthe OEM (DA cage) as well
as the other leading brand.
THE GAME OF WATT SAVING.
There are four main components
to thesavings that oversized pulley system can provide. Bearing quality
and itslubrication, the number of teeth in the pulleys, the cage spring
tension andthe ability of the lower part of the cage to align with the
chain. We are usingbespoke, shielded, oversized full ceramic bearings
that are actually lightlygreased not oiled (nor dry). The difference
between special grease and oil isonly 0.04W in real life conditions,
under load, despite the fact that onepulley can free spin and another
not at all with no load present. What we gainis great durability and
reliability at a cost of 0.04W. Bearings, contrary tocommon assumption,
are not the place of big savings (0.03-0.1W between ahigh-quality
bearings). It’s the companies that sell them want you to thinkthey are
by comparing them to Acera level pulleys.
