CUSTOM Kolossos Oversized Derailleur Cage - Shimano GRX and Ultegra RX800

Get the perfect color scheme for your Shimano GRX 2X (RD-RX810) and Ultegra RX800 series derailleurs. (This includes mechanical and Di2.)

What Kolossos Does for You

First, 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.

Also, oversized pulley systems are an excellent way of reducing the additional friction caused by clutch derailleurs.

Cycling Passion + Your Style

Now, are you ready to take your bike's personalization to the next level?

Choose your favorite colors for every component of your Kolossos oversized derailleur cage using our customizer.

Select colors for pulley wheels, assembly screws, stop pin, front & back cages and pulley covers.

We don't want to limit your imagination so dream big.

Please Note:

- For the best customizer experience, please select your options from top to bottom. After that you can go back and change it up as much as you want.

- Please allow three business days to build and ship your custom Kolossos

- This cage fits on the GRX 1x derailleur (RD-RX812) and will allow it 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.

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

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