cnfabo wrote:that cams roll cage regs is a bunch of japanese jiberish. for a home build "1 st time" seems confusing....
whats wrong with the cages posted???? are those regs writen by a lawyer or something...
The rules aren't that complex, so let's break it down.
The first part just tells you which types of racing needs what cage.
The main hoop has to be within 150mm in front or behind the driver's head, but not directly above it.
Also, in general you're supposed to have as few bends as possible and the main hoop should be as close to vertical as possible.
Your full cage needs at least 6 mounting points, which have to be a minimum of 3mm thick steel, must be a certain size and must be welded to the body. If your cage bolts in then you have to weld 3mm steel plates to the back side of the panel, the same size as the foot of the roll cage.
Then it says the minimum material specs and tube size. Cold-drawn seamless or cold-drawn welded, with a minimum of 50mm OD and 2mm wall for the main hoop and 40mm OD and 2mm wall for everything else. This part is usually where imported roll cages fail, as they may not comply with the material standards, or even if they do, you may not be able to get the paperwork to prove that the material is up to spec. Alloy cages are definitely out, as has been mentioned before.
The two cages which Matberry posted up just recently, would fail to meet CAMS specs for all sorts of reasons. Now, this is just my individual opinion, and I'm not an expert, but to me, here's what's wrong with the multi-coloured Class 11 cage:
The biggest problem is in the fine print at the top of the picture, the tubes are too small, although they are chrome-moly so you might be able to get them certified, but it would involve a lot of arguing and paperwork. Also, the picture doesn't show any proper mounting points where it attaches to the body, so you would have to weld those on. Those weird tubes which seem to attach the front beam to the rear suspension should not be part of the cage. The rear stays and front hoop are both terrible, as the front hoop is made up of several random pieces bolted together which is not allowed, and the rear stays seem to be actually formed together out of a loop instead of mounting to the body, which kind of defeats the purpose of them. Also, there is no diagonal cross-brace welded into the main hoop, which is now a minimum requirement.
Next, the other cage which is photographed. This one is nowhere near as bad, but it would still fail. The mounting feet for the main hoop and front hoops are too small, and there is no diagonal cross-brace. Also, the rear stays are a little bit more bendy than CAMS likes them these days, it would be better if they were just straight tubes welded between the main hoop and the rear floor. You might also get into trouble with the weird "knees" which seem to have been bent into the main hoop for no adequate reason. It looks to me like the designers of that cage were trying to preserve rear seat room rather than maximise safety, which is fairly silly. If a car has a rollcage then it should never have rear seat passengers anyway, as they won't be adequately held in without bucket seats or harnesses, and they'll be killed if they hit their head on a roll cage bar without a helmet.
On the other hand, the photos of the black Bond Roll Bars cage shown on page 1 are perfectly fine, and would easily pass CAMS specs.
