Roll Bar

[RODA]

Question to all people of wisdom.

I am thinking of making my own roll bar and would like to know what the best material is to make it out of.

What is the aproximate height above the body.

Do I install one hoop or two, or one long bar that goes from side to side.

Rod

[boxhead]

It really is a case of makeing it whatever size and style suits the way you want the car to look.
I dont profess to being very good at naming differnt types of steel but I am sure someone in here will.

[Cobra.au]

Rod
It depends on what you want your roll bar for.
I have seen them made out of stainless steel, mild steel and even thin wall tube (for look only) mounted to the chassis and even just to the fibregalss body. Personaly I have a full width polished (brushed) stainless steel rollbar made from shed 40 pipe.
I am currently making a new one out of chrome moly tube putting harness mounts on it and also having a extra leg going onto the passengers side foot well near the tunnel then getting it made all shiney with chrome plating.

in the end it is entirely up to personal taste

Cheers

[400TT]

I assume you know this, but roll bar is not required for approval.

So it's up to you whether you make a single, 2 x singles or large single hoop etc.

Roll bar choice will also be affected by how much you plan to race the car.

To give you a good starting point, Don from Snake Bite uses 2" Stainless tube with wall thickness of 3mm. He supplies them both where rear stay finishes at the body or where rear stay continues through the body to mount on the chassis. So look at making something along those guidelines or at least that's a starting point. Or you could just buy one of his, they are a work of art and made specifically for each kit brand, including CR. We bought one of Don's Roll Bars for the Harrison my brother races.

[Leeroy]

Roda
I got mine from Don Pilling and as Craig said they are a work of art (like most of his work) He makes a CR one which fits pretty well with slight adjustment. It fits at chassis point provided and to the bracket in the rear boot, which should be reinforced (see AussieMike pics) if you were to turtled this would be a weak point. PhilN has the single full width which would be strongest as it mounts each side direct to chassis. Comes down to looks or function I think.

Leeroy

[LoBelly]

Since I'm building at the moment and the Roll-Bar is a 'to do' item I might as well share my thoughts.

To me, the look is important in these cars - so is being able to use them at a track day or similar.

I figure that the events that allow for no roll-bar or a cosmetic/non-regulation roll-bar are going to become extinct.

So I'm looking to see if I can construct a roll-bar that is OK for CAMS and looks right on a cobra.

If not - it might be 2 if I can make them bolt down items

- Anyone have a copy of Schedule J they can share?

LoBelly

[Aussie Mike]

I'm a firm believer of form and function so a cosmetic roll bar was out of the question for me.

Mine is made from 60mm OD aluminium tube. It's 5mm wall thickness so should be plenty strong. I like the look of the slightly thicker roll bar but not too thick.

Definitely look at strengthening the seat belt roll bar mount. I was never very happy with it's design so I added a shear plate. The shear plate is just 3mm steel and doesn't add a lot of weight to the whole thing. It does however make it easier to get it in and out as it's a mountsis a bit spring loaded in standard form. You should also look at welding nuts on the underside of the chassis so you don't need assistance to get the bolts done up.



If you are doing 12" hoops either one behind the driver or a double hoop look at making the 3rd leg structural. I welded in a mount to the chassis that the 3rd leg bolts through the boot floor into.



As for height above the body I think there is a factory height but reckon you are best to sit in the car with a helmet on and make sure the bar extends an inch or so above your head.

Cheers

[Cobra.au]

From what I am lead to believe is that you should be able to get a string line to be 2" above your head when stretched from the top of your roll bar to the highest front structural point of the car.
This makes sense to me as I really don’t think any one would be strong enough to hold them selves in the cockpit of a cobra when turning upside down

[Bryan Wilson]

If you look at the height of my roll bar above my head in the signature photo the bar looks rather large and high.
But with a helmet on the bar is not a lot above my head in this shot.

Now turn the car upside down (heaven forbid) and with belt stretch my head would be pretty close to the road so realy my roll bar height is just about right.
If you look at a Superformance side on the roll bar is a lot lower than your head
Cheers,
Bryan

[400TT]

Originally Posted by Cobra.au

From what I am lead to believe is that you should be able to get a string line to be 2" above your head when stretched from the top of your roll bar to the highest front structural point of the car.

Yep, that makes sense. Flipped over, you would very quickly smash/wear away the fibreglass front guards. It would only stop when it got to chassis/engine. And I don't want to think about what would happen if it continued to roll over.

A lot of GT40's have the same problem, no roll bar. Fibreglass roof wouldn't provide much protection at all. Even my GT40 doesn't have a roll bar.

I personally don't like the look of a big full hoop roll bar that goes the width of the car. But thay is definitely the safest way to go.

I think Harrison are the easiest to fit when it comes to structural drivers and passenger roll bars.

Classic Revival are not quite as easy, but still doable.

When you get to DRB's etc, it gets painfully difficult. Not real familiar with the newer models, but assume they are the same.

[G1947]

Originally Posted by 400TT

When you get to DRB's etc, it gets painfully difficult. Not real familiar with the newer models, but assume they are the same.

Craig, did you have a "functioning" roll bar on your DRB? I have the show one from DRB on mine and know it will just flatten itself if ever the car goes over.
Regards
Garry

[400TT]

Originally Posted by G1947

Craig, did you have a "functioning" roll bar on your DRB?

No, it was also just decorative. Really only had 1 x structural mounting point.

We fitted a structural drivers roll bar to the Harrison as it's designed for structural bar.

Looking at retro-fitting a roll bar to the GT40, now that's a hard task. Definitely worth optioning the chassis unit with roll bar from the factory. Factory roll bar would also help stiffen up the chassis.

[Cobra.au]

Craig
I was looking at a roaring forty GT40 at our last skid pan day and it was fitted with a full cage but I dont know if this is standard for that manufacturer.

[400TT]

Full & half cage roll bars were also optional on the Roaring Forties(RF) GT40's. Well, while you could buy them.

Don't why anyone ordering DRB or RF GT40 these days wouldn't at least option the half cage. But I still see GT40's being delivered without any cage and it's very difficult to fit afterwards.