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Discussion Starter #1
I struck a VW jetta today at about 35mph. Everyone is ok and the insurance and such is well sorted already. The car I was following pulled off and unmasked a stopped car I wasn't able to dodge. Hit square on, no oblique angle or anything.

The Shrock front bumper sustained a minor scratch in the powder coat. No damage I'm able to find otherwise. No airbag deployment, drove it away without issue.

Poor jetta still had the dealer tags on it. Thank god the other driver is ok.
 

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Discussion Starter #3
I don't think it did. I've been in wrecks before with and without air bag deployment, and the other car moved/crunched substantially and the amount of force I was subjected to was low. Not like hitting a tree or something else that won't be moving after you hit it.
 

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FYI, the bumper construction has nothing to do with the inertial sensor for the airbag.
But it does. The more weight added, the more inertia, and the lower the change in velocity during any given impact.

All else being equal, adding mass makes it less likely for the airbags to go off. There's also the fact that the Shrockworks bumper is angled. Some of the forward momentum would have been changed into upward momentum - I'd expect the X to have ridden up the other car, instead of a straight-on impact. That, too, would affect the maximum deceleration seen by the inertial sensor.
 

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Discussion Starter #7
when you needed a crumple zone to be ok I suspect the shrock is a bit worse, and when the crumple zone was just going to be a gleam in some auto body repair guys eye...it's quite a bit better.
 

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But it does. The more weight added, the more inertia, and the lower the change in velocity during any given impact.

All else being equal, adding mass makes it less likely for the airbags to go off. There's also the fact that the Shrockworks bumper is angled. Some of the forward momentum would have been changed into upward momentum - I'd expect the X to have ridden up the other car, instead of a straight-on impact. That, too, would affect the maximum deceleration seen by the inertial sensor.
Thanks for the knowledge.
 

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This is one of the selling points of ARB bumpers, they claim to work better/with the factory sensors to ensure safety in the event of a crash.
It looks like some ARB bumpers have been crash tested and are "airbag approved", and some are not. The bumper for the Xterra and for the Fronty do not mention being airbag approved. That being said, the Titan bumper is.
 

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It looks like some ARB bumpers have been crash tested and are "airbag approved", and some are not. The bumper for the Xterra and for the Fronty do not mention being airbag approved. That being said, the Titan bumper is.
Where did you see that? According to the ARB USA site the first item under product features for both vehicle is air bag approved.

http://store.arbusa.com/ARB-Deluxe-Bar-Nissan-Xterra-2005-14-3438270-P21352.aspx

http://store.arbusa.com/ARB-DELUXE-BAR-NISSAN-FRONTIER-09-13-3438320-P22016.aspx
 

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Discussion Starter #19
The frame has a crumple zone just behind the shrockworks mount so that will still work as intended. Looking at this crumple zone it appears to be modular and meant to be easily replaced with simple welding.

Realize that the airbag sensors measure how much force the occupants are exposed to. So if you hit hard enough that you are going to be injured without airbag deployment, it will deploy.

Another way to say it is the forces at play in the cabin where occupants are are still measured exactly the same and reacted to exactly the same as before the bumper.

What changes is that the shrockworks bumper will reduce those forces in most accidents due to the translation of force into up-and-over motion and inertial transferrence to the other struck object.

An example would be hitting a moose - with your usual bumper you might throw the moose 5 feet and ruin your front end. Your vehicle is exposed to XX G's of deceleration with the primary acting counterforce being initially crumpling and then as the vehicle crumples to it's maximum amount it would be full negative g's in a straight mass-vs-mass equation.

With the tougher bumper the moose takes more of the energy initially and gets thrown 7 feet instead. You get to experience a more rapid deceleration force if the crumple zone ends sooner....or you go up and over the moose and experience much lower forces all around. Essentially you will crumple or decelerate until the standing inertia of the object you hit is overcome, and if you decelerate beyond the threshold of the airbag sensors they will fire regardless of what you put on the front of your vehicle.

Another way to figure it is that acceleration is measured in M/S Squared. As such, as the time that the decelerational forces are exerted goes down, the amount of acceleration goes way up.

So assume that the time period is 1 second, then 5m/s sq is 5/1. This same exact amount of force exerted over a .5 second interval would be 4 times greater and much more disastrous. Crumple zones take that exact amount of force and spread the time component out through the collapsing of metal instead of raw energy transference.

In a collision with something practically immobile like a mountain side or bridge pillar then the shrockworks bumper may cause the airbag to go off SOONER if its rigidity reduces the depth of your crumple zone.
 
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