side project 2 - roll bar crows feet

[advtracing]

Finally have the engineer i wanted to use for this (he's busy building a tube frame race car ) so we have mocked up the shaping in the car and based the style on the photos below plus factory version.

These will be blank undrilled so you can drill to fit your roll bar foot or drilled and supplied with a foot to weld onto your roll bar with bolts.

So question you everyone .....what thickness of steel ?

6mm seems to thin to tap for a bolt , 8 mm seems ok and is bendable or 10mm for grunt but hell of a stuff to bend and shape correctly as there is a double angle on the lower edge .

[Flieger]

I would have thought you'd just put a clearance hole in the plate and use bolts through to the other side of the tub rather than blind threaded holes, or weld on captive "nuts" or tapped bosses. If you want it thick then the cast pieces from I think it was chris_seven would be the way to go to avoid the trouble of bending.

You normally want at least 1.5 diameters worth of thread engagement, so if you are using M8 or M10 bolts then you need at least 8mm plate.

[advtracing]

well Flieger this is where there is two ways to go , the factory way or the motorsport way

from what i can gather all the crows feet where tapped for bolts and not set up as through the chassis. I have two cars with roll bars , the RSR is a look alike with a rep roll bar and the crow feet are to match this and NOT for racing as the early design bars would not really survive a rollover (might help but not in the same spec and motorsports ) the other car has a nz motorsport approved roll bar with 6mm feet that are bolted through the chassis to a plate underneath.

so my build is for the fist option , but if someone wanted to clear the threads and bolt through they could .

Chris was going to cast the units ( anyone heard from chris by the way ? ), this was not the way done by factory that i can see . There is plenty of industrial benders here and i will find a company that can push them out in bulk . I would prefer 8-10mm plate

[sithot]

"Le real thing".

[advtracing]

"Le real thing".

one style of factory , i think swb but yet to sort that . Below is the version i am following i believe 72/73

[sithot]

It came out of a collection of SWB parts.

Good luck!

Tom

[advtracing]

well we have made a mock up out of 8mm plate , hell to bend on the gear we had but wanted to adjust the angles . good tight fit for welding and just need to decide on overall length. I am sending this out tomorrow for pricing to see laser cutting and bending costs.

these photos are in a 73 with a rep RSR roll bar

note the cut in the plate was just for ease of bending the two angles.

[advtracing]

as a comparison , this is on a 70 T shell

[91133]

So with a motorsport background, my take on the 'only' way to go is that you have to comply with the regs rather than history and there are minima for footprint and thickness and fastening methods set in all FIA codes for instance. Second stage is what the local jurisdiction vehicle safety requirements are - many reference the FIA requirements for approval of a non-standard interior. YMMV depending on jurisdiction but I know the rules are pretty tight here in NZ.

[advtracing]

Under nz rules you can have a "rollbar" in a car as "accessory " ( recreate a vintage item ) that does not have to comply with any motorsports rules if used on road only and is not in line with the drivers or passengers head area.(i checked) as such these are for "accessory" use not motorsport use and will be sold as such.
.