Get the perfect color scheme for your Shimano Dura Ace R9100 and Ultegra R8000 series derailleurs. (This includes mechanical and Di2 as well as short (SS) and medium (GS) cage lengths.)

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. 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

- 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**

Level up with Kolossos
Customer reviews
Customer reviews
I’ve been using the Kolosos, and BB for an year now, they still perform as it they were brand new!!! Shifting improved and going downhill with other people is where you will really see the ceramic bearings do their thing!!!
— Tincholeyes
Customer reviews
The Kolossos is definitely my favorite upgrade on my Orbea Occam. It shifts a lot smoother and it looks RAD! I went with a black cage, gold pulleys, & oil slick bolts. It's really cool how you can customize it to your bike. Highly recommend!
— Jkrawczyk71
Customer reviews
The setup has worked so well for me, it’s almost shocking. The hike is a hardtail, and despite this, I’m able to run the derailleur with the clutch off for all my off-road riding, without chain drops. So I get extra drag reduction! I also have to powershift a lot on my local terrain, and it always works. The claimed stiffness is real. Love it!
— Msurch
Customer reviews
Much stiffer than my stock cage and looks way better!
— Dwgreen27

Experience a silky smooth drivetrain

No amount of chain lube or coating can eliminate your rear derailleur's inherent design limitations. The path a chain takes during each revolution requires passing through a chicane of derailleur cage pulleys diminishing your return on each pedal stroke. It's a drag on all geared bikes and why your stock rear derailleur will never perform as efficiently as one with an oversized derailleur cage.




Installation is easy, but does require disassembly of the stock cage.

The process takes roughly 20 minutes, including minor adjustments to the B-screw and limit screws to fine tune placement on the bike.

Frequently asked questions

How hard is it to install a Oversized Derailleur cage?

Installing an oversized derailleur cage is best left to expert level mechanics. Derailleur manufacturers do not support disassembly of the derailleur. For this reason online instructions will be limited.

The installation procedure is also different for each model. Some types are straight forward, with some types you need to disassemble the entire cage and use proprietary tools for the installation. With others you run the risk of having to rebuild the clutch if the parts pop out while you’re happily tooling away. Derailleur failures are typically expensive: the chances of breaking a wheel or a seat stay are probably not worth the risk.

Kogel recommends leaving the installation to a professional.

How hard is it to install a derailleur cage

This depends on the derailleur model. Some require special tools, others can be done with regular allen and torx keys. Please have a look at the installation video for your model for the specifics.

Will my existing chain work?

Probably not. Installing an oversized system demands a longer chain than the one used on a stock derailleur. The longer cage and larger wheels create a need for additional chain links.

Will I notice a difference in performance?

Yes and No. Kolossos has been designed to shift just as accurate as your stock derailleur cage. You will notice reduced drive train friction. Upgrading to an oversized derailleur cage is one step in the eternal search to go faster with less effort.

Are Oversized Derailleur cages noise?

The only sound you will hear is from using aluminum wheels instead of plastic. Aluminum wheels are stiffer and more durable than their plastic counterparts at the expense of a faint rattle when the chain runs across the cogs. We like to call it the sound of speed.

What are the downsides to an oversized derailleur cage?
  • Every installation requires a new chain
  • A slight reduction of ground clearance due to the longer cage
  • Your friends will envy you