I,ve looked in the blue book and the spec for cages beyond metal seems vauge, how big should the plates be that land the tubes on the chassis, do you need a full cage or is just a rear hoop sufficient etc.

I,m now at the stage of my build where I need to incorporate a basic structure, although I am not building to race would like to be compliant as funds may allow a little competition in the future.

Regards Mark

supprisingly little is required, a rear hoop with diagonal, minimum 3 bolt fixing on feet if not welded and one forward or rearward brace, same fixings, off the top of my head not sure of minimum plate size but that's in the book.

Thanks John,

Thats pretty much as I read it.

When surfing on pictures of cars racing (caterhams especially) some have huge structures stuck on them.

Regards Mark

what i described is the bare minimum, if you look at the pic in my avatar that satisfies the regs with one bar too many.

this pic shows 3 variations, can you spot what is well wrong with one of them ?
Rescued attachment mallory 1.jpg

id guess the last car is the one with the problem, the helmet seems to poke through the top of the roll cage - thats going to be one sore neck if the driver ever survives a roll.

No diagonal on the last from this angle, but it still gets through !!!

having raced 4x4's you need afull cage with substantial supports on the chassis, you would not get away with that.

Regards Mark

on the last one, there is a bar right next to his helmet as well.

on the middle one the hoop is next to his helmet as well - doesn't give much room at the side.