can someone tell me the correct hight for a rollcage for competition use. cheers

Don't know the exact measurement off the top of my head but top of head does come into play, have you got the blue book ? The height is relative too the top of your helmet when seated rather than a specific height too the floor, scrutineers a rightly very keen on this,

Here is a scanned pic that may help......

The critical dimension you are looking for is 50mm between helmet and TOP of cage, not underside the TOP. Hope this helps, want any more info I can give you my number as I have blue book in front of me as we speak.
Cheers J.

Thanks for the reply. where can i get a copy of the blue book.

You will get one with your race license, if you need any info before that Don't hesitate too ask. don't know if its available online anywhere.

Since the season is over for most people, someone should be able tol lend/give you a blue book. Ask your local motorsport club.

I think the MSA now have the (current) Blue Book viewable via their website but i suspect it's in their 'Members' section. I don't know if anyone else has had any problems with their site but i couldn't get it to log me on even when i was on the phone to one of their helpdesk people and they tried it for me. :s