Pitch based carbon fibre the key to carbon clinchers?

[Maximilian]

I was doing a bit of research for a university project and came across this


(pitch-based is the dialead)



Modulus is higher but strength is lower.

It seems if carbon rims were made of pitch-base fibres rather than PAN-based the heat issue would be solved.

Any thoughts?

[andy2]

Good find!
Pitch based carbon fiber is already used in the Cervelo RCa, specifically in the downtube to stiffen up the bb, it is also used in our own A2J ROLO bike at various locations;).
Price is astronomic though..

[davidalone]

those are impressive numbers!

that is going to be a REALLY STIFF rim though! ( may be good, may be bad. how much spoke tension would you need to true that wheel if i ever went out of true?)
/
maybe consider mixing the fibers- pitch based for the brake track only ( to keep costs down). sort of what they do with alu aero fairing wheels now

maybe some clever composite engineers like andy from a2J can tell us if that is possible.

[andy2]

For the record, I'm not a composites engineer; our tech boss Jon Gunner is though. He's the one that tells me these things.

[thisisatest]

Boy, it would be interesting. Pitch fibers, or at least the stuff I've messed with, is super brittle. Regular carbon, before the resin cures, you can tie in a knot. Pitch fibers are like uncooked spaghetti. Just goes snap.

[davidalone]

that would agree with the relatively lower yield strength adn high tensile modulus.