Thread: custom front bar

You are correct, all SRS vehicles must have a certified SRS compliant bar.

In the event something goes wrong, having the wrong bar can nullify your 3rd party insurance, and leave you open to law suits..

And if the crash pulse is wrong on the new bar, could end up hurting you and the co-pilot.

What about creating a bar that uses the crush cans that ARM or TJM use.???

Is it splitting hairs about the certification... is it the actual bar that is certified for impact testing or the correct loading on the crush cans to deploy the air bags correctly???

Thats what I have on mine
Welded on arb crush cans on my tube bar.

Originally Posted by bitdist

Thats what I have on mine
Welded on arb crush cans on my tube bar.

Wouldnt comply... As the whole assembly needs to be tested and the different structure in front of the cans would have a different crash pulse

Can anybody throw me a link that comments on bull bars needing to be certified on vehicles with SRS? Particularly NSW as I could only find references to the form of the bar and protrusions.

Originally Posted by Slunnie

Can anybody throw me a link that comments on bull bars needing to be certified on vehicles with SRS? Particularly NSW as I could only find references to the form of the bar and protrusions.

i have the aus standards book AS4876.1-2002 to say its vague is an understatement tells you indepth about how to test your bar on kids though

this is worth a read.
http://www.nrmabusinessmotoring.com....0standards.pdf

its VFPS pt1 that i have, nowhere in it does it mention SRS...


this is abit on the SRS side of things
The Airbag Debate
The next option to consider is how the bullbar is mounted to your vehicle. Some bars completely replace the current bumper from the 4WD, while others incorporate the existing bumper into the design. You'll also need to choose between a bar which uses mounting brackets versus a chassis mount system. Newer bullbars may utilise deformable, impact absorbing mounts to assist with airbag deployment in the event of an accident.

In terms of new car warranty and correct operation of all safety devices on your 4WD, there is no thornier issue than that of bullbars and airbag compatibility. A quick explanation of the airbag concept is necessary to fully understand how an incompatible bullbar could have a serious effect on your vehicle, and your safety.

Current vehicular designs incorporate crumple zones into the chassis, which determines the vehicles 'crash pulse'. The crash pulse is a measure of deceleration, usually taken from the occupants position, when the vehicle hits an obstacle. The front of the vehicle has an almost instant stop, but because the vehicle is designed to crumple, the occupant's rate of deceleration is considerably less. The issue of collision related injury to passengers boils down to the rate of deceleration. The faster an object decelerates, the more load there is on the object and it is this force that can have the most devastating effects on vehicle occupants.

The airbags in a vehicle are designed to deploy at precisely the right moment, timed to the millisecond. Any disruption to the vehicle's crash pulse would have an effect on the timing of deployment of the airbags. With this is mind, it fell to the designers of bullbars, both original equipment and after market, to come up with a system that incorporated the airbag sensors, and didn't disrupt the vehicle's crash pulse. In order for some manufacturers to achieve this goal, it has been necessary to engineer extra crumple zones into the mounting brackets of the bullbars.

Most bullbar manufacturers claim to have incorporated this new technology into their designs, with many of the manufacturers listing this as a feature in their advertising material. However, claims and counter-claims from both sides of the debate have created confusion for buyers.

Many vehicle manufacturers are currently following the line that they cannot guarantee correct operation of the vehicles airbags in the event of an accident, if an after market bullbar has been fitted to the vehicle. On the other hand, many after market accessory manufacturers claim that their products have been strenuously tested to comply with the rigorous airbag compatibility and design standards, and that any such talk is merely a scare tactic used by the vehicle manufacturers to corner a larger share of the 4WD accessory market for themselves.


cheers phil

Phil, thanks for this. I suspected this might be the case despite advertising etc, but didn't have access to the same resources as what yiu have.

Originally Posted by Slunnie

Phil, thanks for this. I suspected this might be the case despite advertising etc, but didn't have access to the same resources as what yiu have.

when i was interested in making bars for defenders i decided i had better buy the aus standards to follow all relevant laws etc... i was very dissapointed at spending $70 on 12 pages of nothing

the quote information about the SRS stuff has to have been lifted from somewhere but i still cant find where.
mike, do you have a link to the standards you refer too?

cheers phil