Composite tubes.

Frequently found tubes were analysed and compared with carbon fiber-epoxy tubes manufactured in a laboratory range. It was found that compression properties of tubes produced in our laboratory have properties comparable or even higher than those found in sports devices on the market. The composite material with carbon fibers treated in HNO3, in combination with epoxy resin with addition of Versamide has an adventage over another composite specimens. The positive influence of curing time was announced.