Big pulley wheels were not the final step to free speed. Kolossos now comes in Aero, shielding your wheels and chain from the wind for those riders looking for maximum output. Aero Kolossos is built with Kogel Ceramic bearings and road seals. Fully built in CNC machined aluminum with an internal spine for maximum stiffness, Aero Kolossos will help you cut through the wind as well as help you maintain shifting accuracy. When it comes to marginal gains, there is just no point in gaining a few watts, only to give away your benefits every time you change gears or hit rough tarmac. While the obvious use is for triathlons and time trials, we did not want to restrict the range of use for these cages. The Aero Kolossos is equally at home in road and crit racing, where the terrain can be bumpy and shifting happens often and aggressively.