I have a glass fibre car with a rotten mild steel space frame chassis. Is it feasible to replace (partially replace) with your carbon fibre tubes and sections? I mean would they be strong enough. The main rust is in the main backbone chassis and the sections that come out along the sills. If i have a 1inch mild steel tube section what would i replace that with for same strength?

I would replace complete section for instance the whole backbone not just patch up the rusty bit.

Graham

I would be careful about using carbon tubes.  certainly do NOT just replace a metal tube structure with a similar carbon tube structure as the material differences are significant and would not perform in the same way.

Not saying carbon tubes might not have a place in your build, they may well do, but it has got to be carefully planned and designed to take advantage of the differing properties between steel and carbon.

Carbon tubes would certainly perform differently in a crash for example.  

On competitions like formula student, the teams wishing to use materials other than the generic technical spec, have to perform tests and calculations to prove "structural equivilency" both from an engineering perspective (they are doing it to learn, not just to win) as well as safety reasons.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant