roll bar tube
 

sorry if this has already been asked (im sure it has) but i cant find it.

What diameter tube and what wall thickness do i need for the roll bar? Also does it have to be seamless? My old man has a mate whos an industrial pipe fitter and he has use of a mandrel bender at work, so i was going to have a crack at making one myself. Obviously i will probably have to compromise depending on what size formers he has but Im sort of toying with the idea of a full cage if the steel doesnt cost the earth.

thanks

I made the cage for my roadster from 50.8 o/d x 3.2 wall erw. Should be plenty strong enough.

You only need seamless if you want to race professionally ie FIA.

The ones ash had made were 50.1mm and 3.2mm thick ERWlink here.

The MSA call for seamless tube for cages and roll bars as well, even at club level.