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Rollbar with trim
christim - 22/4/20 at 03:36 PM

I like the idea of having a rollbar all trimmed up for my build, so have bought one I think will work, with a bit of fettling.

But it's interesting to see what passes as strong enough, given the requirements in the IVA manual and headaches people have written about getting seatbelt mounts passed, etc.

Here's what i'm doing, would be interested in your thoughts

Mini R52 rear rollbar:


What it looks like with the trim off:


What it looks like with the arms cut off to a length that means the headrests are in a suitable position (i'll be making the headrests taller so they reach down to the seats with 5mm gap per IVA):


Work that'll need doing:
1) cut down the middle and extend out so the headrests line up with the seats
2) add an additional supporting bar in the middle for extra strength
3) 1 and 2 above will be covered in leather trim to match the seats and headrests
4) triangulation at the seatbelt mounting points


What the bar looks like when dissected and what i find weird considering this is a rollbar:
1) It's made from Aluminium. Ok it's thick stuff but still i wouldn't trust it
2) The seatbelt mounts are (tig) welded on to the bar with no triangulation or additional support, with Rivnuts to bolt to
3) No triangulation anywhere to support an impact. (maybe the original legs being bolted up gives it sufficient strength?


What this means...
I'll be taking the dimensions from this bar then scrapping it and going to "tube-bender.co.uk" for a steel bar to be made up


I'm sure these things go through a load of safety testing before going on production vehicles right? So i wonder how it manages to get away with no additional support, either for the seatbelt mounts or any additional bracing? I'm sure if this setup was presented at IVA it'd be a fail?
Is it one rule for IVA and another one for production cars?


SJ - 22/4/20 at 03:43 PM

quote:

I'm sure if this setup was presented at IVA it'd be a fail?
Is it one rule for IVA and another one for production cars?



Yes, absolutely it is. Type approval is for production cars.


adam1985 - 22/4/20 at 05:40 PM

Arent they just decorative roll bars? I seem to remember something about 2x rams that eject out from behind the seat in a roll


christim - 22/4/20 at 09:36 PM

SJ that's interesting, I thought type approval was like an M1 test but then with an agreement that if all the cars were made the same way then they wouldn't each need testing...
but thinking about it it makes sense they're completely different...I guess the car companies can test and prove their design is up to a set standard, whereas without being able to prove our cars' design with stress tests the requirements a more strict