Carbon bolts: the ultimate weight weenie component?

The bolts on your bike. They're made from what? Heavy, old fashioned metal? They're holding you back. What you need is some sleek new Carbon bolts, like these ones available from Poshbikes.

"You may have heard of 'Carbon PEEK', which has been used in many F1 and fighter Aircraft applications," says their website. We hadn't, but anyway these screws are produced by a similar process, CFM PEEK. Not wishing to blind you with science, but "The Polyaryletheretherketone (PEEK) materials are semi-crystalline, high purity polymers comprising of repeating monomers of two ether groups and a ketone group," according to the very helpful British Plastics Federation website.

CFM, as you all know of course, stands for Composite Flow Moulding, and we learned all about that at the very helpful Plastics Technology website. It's a wonderful thing is the internet. CFM has two advantages: it allows you to pack a lot of Carbon Fibre into the component, and you can do clever stuff with the orientation of the individual fibres.

For these screws, there's an external layer of radial fibres in a helix to give structural integrity to the thread, and through the middle the fibres are unidirection for better strength under tension. The resulting screw has a claimed yield strength greater than that of a steel screw. Poshbikes are hedging their bets for now though, suggesting that you might want to use them in applications where Aluminium bolts are permitted.

They're currently available in a limited range of sizes in M5 and M6 threads, and they weigh between 0.7 and 1.3g each. Prices are £36 for a pack of four M5 bolts and £44 for four M6-threaded bolts.

www.poshbikes.com