Hello all,
I'm part of a team of sixth-form students partnered with an engineering company trying to find applications for a new carbon-fibre composite. I'm investigating kayak paddle shafts. I already know they can be made from aluminium and
carbon/glass fibre/kevlar composites, not to mention wood.

I would like to do a mechanical properties comparison between the new composite and the existing materials, however I ran up against a problem: the paddle manufacturer sites I have visited do not specify *exactly* what kind of composite they are using (e.g. 30% glass fibre, 10% Kevlar in polyester resin [no, I just made that one up :-)]).

Does anybody know of the website of a manufacturer of this kind of tubing that will have that kind of information there?
I know composites are synonymous with 'horrendously complicated', and different manufacturers will be using different kinds, but even some idea would help enormously.

Also, what kind of Aluminium is commonly used to make shafts? (e.g. something like Aluminium 7075 T730)

And some general questions:
Are carbon fibre shafts not recommended for white water paddling because they are brittle? How dangerous is it to have a shaft break in use?

When choosing the flex in the paddle shaft you're trading efficiency in paddling against comfort (am I right?) So what does it actually feel like to use a paddle with a very high or low flex (I've used a kayak before, but not much)?

Any help would be much appreciated

Stephanie Kocura