Experimental Prototypes carbon fiber cassette for 10-speed road bikes

Tucked away in Insjön, Sweden, is a little company called Experimental Prototype that’s making the kind of things that we love to geek out about. Things like a 63g custom ratio 11-23 road bike cassette with eight of ten cogs made from carbon fiber!

For just €300 and about 6-8 weeks of breathless anticipation you can get one of your very own in any gear range and combo you want. Need more? They specialize in making pretty much anything you want. By hand. Usually from carbon fiber or titanium from the looks of things. Thinks like replacement Lefty steerer tubes, ti chainrings and cassette cogs and sooooo much more. Take a quick spin through their website for a gallery of lust-worthy hacks and one-off upgrades. And by quick spin, we mean 20+ minutes of your life, gone.


Experimental Prototypes 6-4 titanium and alloy 42-36T chainrings for Cannondale hollowgram si cranksets

This is the 2nd version of a 6/4 titanium chainring combo for Cannondale’s Hollowgram Si crankset. The set up here weighs in under 90g, a full 10g+ savings over version one. They claim it has much improved durability over aluminum, too.

Experimental Prototypes 6-4 titanium 36T cassette for Shimano spline freehubs

When 34T just won’t do, there’s a custom 6/4 titanium 36T cog Shimano/SRAM splined free hub bodies. Both this and the chainrings above are water-jet cut from 2.0mm titanium sheets, then the teeth are profiled.

Experimental Prototype 7075-T6 alloy ultra lightweight derailleur pulley and jockey wheels

Head Engineer Mattias Hellore tests many of these products on his own bike, giving them a little real world love, but not everything on their site is ready for prime time. These are an unfinished prototype set of 7075-T6 pulleys that have the smallest bearings we’ve ever seen.


  1. Speedy on

    It’s great they are pushing the weight boundaries of parts like these. However, I am a bit concerned that the weight savings will come at the cost of performance (and a bit of reliability) Look at all the small individual tooth detail on a shimano or sram cassette. Then look at this (prorably cnc’d) carbon cassette. The teeth are not shaped in any way to aid shifting. The same goes for the chainrings. Compare those to offers from the big boys, as well as Praxis or Wickwerks. With no ramps, or pins, or any tooth shaping on that large ring, I would expect some of the worst ever. Is it worth it?

  2. greg on

    Well it does say its the “second version”. All of those products are labelled experimental. I think it’s awesome and despite being expensive, it’s reasonable enough.

    The centerlock rotor floored me. A race day item perhaps but so cool.

  3. Speedy on

    @ greg – What center clock rotor? Are you referring to that bit 36t cog by chance? Or was the rotor over on their website and I am just not finding it?

  4. Nick on

    I use one of his ti chainrings on my M985 chainset, as I wanted to go single ring and he was about the only person doing 88mm BCD rings at the time. Very impressed frankly. It’s showing next to no signs of wear after a years use. It got very bent (a good inch out) when I broke a chainring bolt, so I bent it back in a vice. Was about half the price of a Shimano one too!

  5. G Moto on

    I was thinking about ordering a custom 30mm spindle cut to size with a carbon center body for about a 30+ gram savings. Then I saw where a guy did just that, bought a custom made carbon aluminum 30mm spindle from Experimental Prototype for his W.Weenie XC bike. When he put the pedal to the metal on an uphill, the spindle exploded. I hope he got his money back. That said , I still think it could work – with solid carbon, instead of bonding aluminum to carbon. Or else some kind of bombproof bonding…


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