After introducing Kolossos last year for road and gravel bikes, it was about time we gave some love to cross country, trail and marathon riders.

Translating what we learned from the drop-bar bikes to 29-inch wheels helped us deliver stiff, bordering on overbuilt, cages that keep chains running smoothly and shifting accurately.

The Kolossos for Sram Eagle is our burliest oversized derailleur cage to date. 

Mountain-Bike Drivetrain Challenges

Mountain bike drivetrains cause higher friction than road bikes due to smaller chain rings, use of 10 tooth cogs on the cassette, and increased chain tension of clutch derailleurs.

Further combating efficiency and rolling resistance are those larger knobbier tires that don’t roll smoothly like a svelte road tire.

It seems obvious why one would want to reduce drivetrain friction, and an oversized derailleur cage is a meaningful way to gain back a portion of these performance losses.

Our oversized derailleur cages represent a tectonic shift in mountain biking performance: like dropper posts, disc brakes and so many other innovations we consider mandatory. 

Designed for Guaranteed Performance

Mountain bikes are designed to ride over the toughest terrain imaginable, zipping close to rocks, roots and all types of soil conditions, so we had to design a product that guarantees performance.

We did this by focusing on the following design elements.

  • Reduced Friction – First, we purposely designed the Kolossos for Eagle cages for reduced friction by incorporating larger 14 and 19-tooth pulleys. Those larger pulleys mean less rotation and wider bends in your chain, two things that reduce friction. A nice side benefit is that your pulleys will last longer because they rotate less often.
  • Shifting Performance – Secondly, we had shifting accuracy and chain retention in mind; something near and dear to all XC, marathon and enduro riders. To this point, we over-engineered the cage to be incredibly stiff. A stiff cage means snappier shifts. Coupled with the larger pulleys Kolossos invites rapid shifting in any riding scenario.
  • Ground Clearance – Third, Kogel’s Eagle Kolossos design also prioritizes ground clearance. By carefully redesigning the geometry of the Kolossos compared to the stock cage, we managed to fit in the giant 14 and 19 tooth upper and lower wheels AND keep the total length of the cage within 2mm of the non-oversized cage.
Plus, a nice side effect is not needing to install a new, longer chain when upgrading to Kolossos for Eagle. Keep your current chain and replace it when worn.
  • Efficiency - Oh, and let’s not forget that one element near and dear to any rider counting grams in their sleep. Our scales say the Kolossos for Sram Eagle weighs the same as the GX Eagle version of rear-derailleur cage.
Compared with a stock XX1 Eagle that’s a weight penalty of 9 grams; about a third of an ounce. (That’s less than an empty beer can.) Hopefully, you’ll sleep better now knowing this and after consuming the contents of that can.
  • Road vs Cross Seals – Finally, our Eagle Kolossos further prioritizes efficiency and lower friction by shipping all Kolossos for Sram Eagle with our road seals.
This performance-oriented decision means you will go fast, but also means you do not have maximum protection for wet conditions. However, all Kogel products are designed with seals that can be easily swapped back and forth.
Run low friction seals during the dry season or race days and swap them for cross seals when the weather looks less than perfect. I personally run road seals on all my mountain bikes year-round, but hey, I live in a desert.

Uniquely Yours

If you’ve been following Kogel for some time, you probably have noticed our passion for performance AND personalization. (Where does it say you cannot have both the best performance and color choices that match your personal brand?)

Kolossos for Sram Eagle is now available in three color schemes (black, Midas gold and fire-engine red) or you can show your creative side in the customizer for that perfect match to your ride or kit.

I hope by now you’re excited about expanding your bike universe and giving our latest Kolossos a go. If you still have questions, hit us up on email or live chat. We’re here to help.


Ard Kessels