When you demand even more speed than an oversized pulley cage will give you, you need the Aero Kolossos Oversized Pulley Cage. This aero cage helps you to achieve the maximum power input by shielding as large an area of your pulley wheels and chain from the wind as possible.

Reducing chain articulation through the use of large upper and even larger lower pulley wheels decreases drivetrain friction, for a smoother ride and improved energy transfer from the pedals to the tarmac.

Built from CNC machined, aircraft grade aluminium, with an internal spine for maximum stiffness, aero road seals and fast ceramic bearings on stainless steel races, it will ensure that shifting precision is maintained and that hitting rough tarmac won't erase the aero advantages you've gained.

With a shape that minimises drag, so that you can maintain higher speeds with less effort, the Aero Kolossos Oversized Pulley Cage is as at home in bumpy crit and road races as it is with time trialling and triathlons. Choose the right model to match your derailleur and discover how fast you can ride.