Whether you need one to meet the rules of a racing sanctioning body or just want one out of your own concerns for safety, roll bars and roll cages provide needed strength to a chassis and needed safety to a vehicle’s occupants in the event of a crash. For the DIY’ers out there who aren’t taking their vehicles to a chassis shop to have one installed, a DIY roll bar or cage is the solution. S&W Race Cars now has an instructional video on how to measure for one so you can send the measurements, have them bend and cut the tubes for you, and receive a customized roll bar or cage that requires minimum fabrication on your end.
S&W offers a data sheet, a diagram of the roll cage noting the necessary measurements it needs, and paper protractors for you to collect the appropriate angles all on its website for you to download. The diagram shows you the various dimensions you need to measure and the data sheets collects that information for S&W.
In the video here, you can see how S&W shows you how to measure for main hoop height and width, door bar and down bar length, lateral bar length, as well as the various angles for the main hoop and front down bars among many others.
S&W also makes note when you should add or subtract from the dimension you measured. For instance, when measuring for Dimension A, which is widest part of the car’s floor where the main hoop’s two points connect to the floor, you’ll subtract an inch per side so that the bars aren’t pressed up against the interior panels. This also allows for you to be able to weld all the way around the tube as it rests on the support plate.
Having someone to help you take the measurements is also recommended, as they can hold the end of the tape measure in place when extended, and it doesn’t hurt to have someone double check your measurements.
On the data sheet, you’ll also find options for material type (mild steel, chromoly, etc.) and the diameter of the tubing, which may be determined by the sanctioning body, the class, the et/speed. Some sanctioning bodies may require different types of bars in certain places as well, so feel free to contact the sales department for any additional questions.
Once you’ve gathered and written down your information, you can email or fax the data sheet and S&W’s sales department will contact you with a pricing estimate. Then it’s up to you to handle the final assembly. Check out the video for more details to see if installing your own roll bar or cage is right for you.