Hi Folks, thanks for making this forum.
There's loads of great advice here. 

I've been making 60 cm diam rings by bending 5mm carbon rod , setting the ends inside a cuff and sewing these inside a dacron sleeve.
This puts the carbon rod under a lot of initial stress. So much that vinylester rods break randomly in the night. I should use epoxy.
From here they are compressed even more by 6 lines on a tensile torque transmission system. 
This is a very weird project making a flying wind turbine... https://windswept-and-interesting.co.uk

I'd love any suggestions or advice on how to make these rings better. ..I can't afford a bike wheel for every ring in a stack
Is there anywhere which makes a set pultruded coil which I could cut and set as a ring?
Is there anyone makes a prepreg packing or sealing gasket I could wrap around a large cylinder?
Should I just make corner blocks and use straight rods?

Thanks in advance

I'm a little concerned now that the Vinyl Ester pultruded rods may actually have a better ultimate tensile strain rating 1.4% than the epoxy 1.1%
So Vinyl Estsr should be able to withstand the bending strain
Vinyl Ester
https://www.azom.com/article.aspx?ArticleID=2001
Epoxy
http://www.goodfellow.com/A/Carbon-Epoxy-Composite-Composite.htmlhttp://www.goodfellow.com/A/Carbon-Epoxy-Composite-Composite.html
How to calculate minimum bending radius
https://www.reddit.com/r/engineering/comments/5y2mcp/question_maximum_bending_of_a_carbon_rod/
Thing is ... If my rod is 5mm and the bend radius is 320mm (64cm dia 2m length rod)
Then I'd have thought my max strain level (seperation / radius of curve ) is only 2.5mm/320mm = 0.0078 or 0.8% ish so my rods shouldn't be snapping.
 It's only the odd 1 or 2 which pop 
and by 2 different methods either a straight snap or a crushed delamination
I may have to start making my own custom gear