Kogel is bringing low friction and precise shifting to GRX 12-speed gravel bikes with this Kolossos oversized derailleur cage

This upgraded cage fits mechanical12-speed (RX820 series) drivetrains for Shimano GRX 1X rear derailleurs .

About our Kolossos Oversized Derailleur Cage

Named after the Greek word for a statue, the Kolossos Shimano GRX 12-Speed Oversized Derailleur Cage features large pulleys (18-tooth narrow-wide bottom and 14-tooth top) and is constructed with our strongest cage design yet.

Designed to enhance chain retention and reduce friction, Kolossos cages are a critical component for gravel riders seeking top performance.

The overall length of the Kolossos is within a few mm of your stock cage, so ground clearance is not a concern. It is also equipped with road seals for optimal efficiency, but can easily be switched to cross seals for wet riding conditions.

Fitment

This cage is actually the same as our XTR 12 speed MTB cage and works perfectly on 1x gravel derailleurs. GRX 12 speed (RX820 series) only.

If you run a front derailleur on your gravel bike, have a look at our Kolossos cage for GRX 11 speed. It runs well on a 12 speed 2x derailleur.

**Kolossos is a component upgrade for existing rear derailleur. Derailleur not included**