Kolossos Oversized Derailleur Cage - Shimano GRX and Ultegra RX800

Oversized ceramic pulley systems are an excellent way of reducing the additional friction caused by clutch derailleurs.

Kolossos is the Greek word for a statue, much larger than the original subject. Seems fitting for an oversized derailleur cage.

Imagine the performance of replacing your stock pulleys with a ceramic 12-tooth top pulley and a 19-tooth bottom pulley built on the stiffest cage on the market.

Besides reduced friction, this cage is built with shifting accuracy and chain retention in mind. Kogel Bearings has always had a strong connection to off-road disciplines. We wouldn't build it if it weren't gravel proof.

This model is built for the GRX 2X (RD-RX810) and Ultegra RX800 series derailleurs. This includes mechanical and Di2.

This cage fits on the GRX 1x derailleur (RD-RX812) and will allow to shift through the entire range on an 11-42 cassette, but it will leave a large spacing between the top pulley and the smaller cogs. Expect shifting to be less snappy in these three gears in a 1x setup.

Please note** Installing this oversized derailleur cage typically requires replacing your chain to accommodate the larger pulleys.