Hi Hojo,
Thanks for your reply.
I have looked a bit into bike manufacturing, Bladder moulding looks like it's perfect for manufacturing complex shapes. I've never heard of expancell. A quick google search suggests that they're microsphere additives? I will look into them further.
I wondered if you could get flexible prepreg tubes that could then be fitted into a mould and then cured? For simpler tube sections, it could potentially cut out the process of needing to cut specific shapes and carefully fitting them in the mould.
I was also thinking of maybe using bladder moulding to create corner joints to connect lengths of straight cured tube (kind of like plumming!)
Cheers,
Alex