Roll Bar

[Guest mark little]

hi all,

 

having no luck getting a roll bar, so I'me going to get one made. what gauge of pipe is required, wall thickness and what is the overall diameter of the bar, I'me going to get it made in stainless steel, is that ok or are there any problems using stainless.

 

Another thing, are the diagonal braces required going down to the rear, some cars have them some don't.

 

cheers Mark

[fry61]

As best I remember -- 50mm diameter tube x 2mm wall thickness & must have very little "necking" in the bends so best if mandrel formed. Braces on our 2B are 38mm x 1.5mm wall & essential IMO it triangulates the structure & must make it more than 3 times as strong. Check above with IVA manual, I'm sure details are listed.

[Snapperpaul]

It's just cosmetic unless racing then 50mm x 2mm

If fitting seatbelt mounts it would need to be strong and braced

IMHO best to make it strong enough to actually protect you if you did roll

 

I believe on the monocoque cars it was just industrial central heating pipe

[Guest chris brown]

As Paul says there is no requirement for a roll bar so you could make of whatever you like but I agree if you make one make it strong enough to protect you which with the mono chassis includes some strengthening

[Guest mower man]

I have a mono car and the bar is stainless 2 mm and braced to the rear panel . Orig builder was a s/s fabricator so it may be not factory I think it would give some protection but not like a race cage , it helps with full weather and surry top install too mowerman

[steve in stockport]

RAC spec roll bars available for Westfields from .... Westfield sports cars, best part of £300 though. Possibly worth doing a temporary membership on westfield forum and see if anybody is selling one as the RAC is a popular upgrade over there

 

Or merlin motorsport will make you one, again for a steep price

[brumster]

If it's just for show then make it out of what you like, but if you intend it to do some good then I wouldn't make it out of stainless. If you're after a level of certification then I could sit and quote the MSA guidelines to you but they're pretty in-depth, would be easier if you just headed over to section K on the following :-

 

http://www.msauk.org/site/cms/contentviewarticle.asp?article=1176

 

Even if you don't build it to MSA/FIA spec, you can use the regulations above to guide you on what is clearly considered the right way to do things. For example, minimum 3mm steel chassis plates, CDS tube of at least 350N/mm^2 yield, and various diameters and wall thicknesses from 45x2.5mm to 50x2.0mm for the main structure, to 38x2.5 or 40x2.0 for the additional tubes/supports.

[Guest mark little]

thanks for that, its there to do a job as far as I am concerned and its one of those things that you do'nt cut corners on.

 

The rear braces, are they welded to the rear chassis uprights or bolted ?