Board logo

Rollbar with harness bar and backstays
andrew.carwithen - 29/10/05 at 02:58 PM

I'm in the middle of fitting my rollbar to my Avon.
It is a standard Tiger single hoop full width rollbar which has been modified by having a harness crossbar and backstays added.
I fully intend to fit 4 point harnesses and attach to the crossbar by way of the eyebolts and threaded tubes which have been fully welded through the crossbar.
My query is this:
I think I'm right in thinking that if the harnesses are attached to the rollbar, then the rollbar has to be bolted either side using FOUR high tensile bolts.
The problem is, that on an Avon, only THREE bolts per side can be used as a chassis member gets in the way of a fourth bolt.
Does anybody know if, since I've fitted backstays - which will be bolted to the lower chassis with two bolts for each stay (and hence giving much greater rigidity,) I can get away with fitting the one less bolt either side for SVA?

Cheers,
Andy.

caber - 29/10/05 at 08:53 PM

Do you actually need a roll bar for an SVA? original 7s didn't have them!

Caber

andrew.carwithen - 29/10/05 at 09:11 PM

quote:
Originally posted by caber
Do you actually need a roll bar for an SVA? original 7s didn't have them!

Caber


Correct, you don't.
But if you do fit one and the seatbelts/harnesses aren't attached to it, then for SVA purposes I believe it is treated as a cosmetic add-on and is only subject to the usual radius tests.
However, as I'll be attaching harnesses to mine, then it is subject to a lot more stringent scrutiny (for obvious safety reasons!) in how it is secured to the chassis.
It is the level of security I'm trying to establish.
Looks like I'll have to try 'phoning the SVA centre on Monday....

Lightning - 30/10/05 at 09:06 AM

weld it on. the upper mount is easy to get to. You can grind it off if you want to change it.

andrew.carwithen - 30/10/05 at 10:17 AM

quote:
Originally posted by Lightning
weld it on. the upper mount is easy to get to. You can grind it off if you want to change it.


...Trouble is, I've just had the rollbar powder coated..so I don't want to ruin that!

Baldrick - 31/10/05 at 04:39 AM

I think that's what I have - not near the car so can't check (some photos in archive). The only issue I had at SVA were the belt mountings. If you are going to mount your eyebolts as you say then I doubt you will have the same problem. I have no recollection of the SVA man even looking specifically at the roll bar mounting bolts and certainly not actually counting them. My guy seemed more swayed by overall standard of build than anything else.