With the rising number of Locost terminations, who has fully tested their roll bar in the manner it was designed for?
Was it welded or bolted in?
How was it bolted?
Was it braced?
Did it withstand the test?
Any recommendations for future Se7en roll bars?

Actually been wondering the very same thing. I'd be a bit worried that no responces could be misinterpeted. No survivers or none flipped?

this is a standard mk rollbar, bolted on, with no back bracing, and due to the spacing of the bolts, would suggest at least two bolts were into rivnuts. afaik, the driver at least walked away.

it's what made me think my roll bar would suffice, for now at least

it's taken from snoopy's archive (hope you don't mind). there's a few more pics of the same incident, and the car before.
hth
tom
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I was concerned some time ago when I read of how some builders were intending to attach their roll bars. Some people were tossing bolt grades around and had absolutely no idea what they were bolting their safety devices on with, or even if the sub-structure was up to the task.
More recently, over on the Trike section, Triton stated he wouldn't care to be upside down in a car with a bolted on bar.
There's nothing wrong with a bolted on roll bar as long as it is carried out with the correct grade/Class of fasteners and the bolting points are strong enough.
If properly done, there's more chance of the bar breaking away at the HAZ than the bolted joint.
And so the question arose; how many Locosts are actually safe in the event of a roll over?

it was in a bad way by the looks of the shocker ripped in two, but the tank stayed in one piece!

tom
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we had our rollbars analysed by rac msa and have been passed and recognised by them,
even on a basic roadcar we fit rear hoop diagonal and two rear stays in 2.64mm wall 1 3/4 cds, yes it costs us more to manufacture the chassis but i like to sleep at night and on the other side how do you value your life !!!!! , have seen some truly shocking examples of cages throughout the years 1.5mm seamed tube etc held on by rivets !!!!

I have no doubt Marc that your bars are of the highest quality.
I used to keep a file of horror pics of abismal workmanship just to remind me to do everything right regardless of cost.
I haven't seen anything quite as bad as a roll bar that was riveted on. Whoever did that should have been restrained on the ward and not allowed out on day release.

Weld them on.....because the Locost and most 7's are not really suited to bolted on roll bars if you value your life....using rivnuts to bolt a roll bar on is asking for trouble...and 2.6 wall CDS roll bar and rear stays everytime here too.

My cage for the Locost was MSA approved for the Locost and Kit car series, used 38mm 2.6 wall CDS and was fully welded to chassis at fabbing stage...not a cheap thing to do but allowed peace of mind.

As for using rivnuts...you will be surprised how many do that to hold roll bars on....ok for a bit of grp etc but not a roll bar

I might be a mercenary bast~~d, but first dibs on the raditor !

I had been thinking of taking the 3mm plate on which the rear suspension mounts across the whole of the back of the cockpit to mount/weld cobra type roll bars on. Given this topicwould anyone care to comment if the structurebelow is sufficiently strong or should I take them through this plate down onto the floor of the car

You'd be better off running a length of tube across and also bracing up to the centre of it, or to where the individual Cobra type bars attach.

Thanks Rorty that is a simple modification.