Aftermarket bumpers for trucks

[RevolverRob]

No steel bumper provides protection for the vehicle against high-speed collisions.

The vehicle has crumple zones. Adding steel to the front only makes it more likely that the crumple zones will be initiated at lower speeds. It's counter-intuitive at first, until you think about the physics for a minute. If the crumple zone was designed to initiate at X force and force = mass x acceleration - if you increase mass and keep acceleration constant you arrive at X force faster than lower mass and same acceleration.

Similar, if the airbag sensors are set to deploy at a certain force rating, adding mass allows that threshold to be met sooner. In most cases, this is what will happen if you add a steel bumper, the airbags are more likely to deploy in a lower speed collision.

Steel bumpers help with approach angle and protection against low-speed collisions. Don't count on using them to ram through a barricade of people or deer at 50+ mph. At 20 you might get away with it.

[Lester Polfus]

No steel bumper provides protection for the vehicle against high-speed collisions.

The vehicle has crumple zones. Adding steel to the front only makes it more likely that the crumple zones will be initiated at lower speeds. It's counter-intuitive at first, until you think about the physics for a minute. If the crumple zone was designed to initiate at X force and force = mass x acceleration - if you increase mass and keep acceleration constant you arrive at X force faster than lower mass and same acceleration.

Similar, if the airbag sensors are set to deploy at a certain force rating, adding mass allows that threshold to be met sooner. In most cases, this is what will happen if you add a steel bumper, the airbags are more likely to deploy in a lower speed collision.

Steel bumpers help with approach angle and protection against low-speed collisions. Don't count on using them to ram through a barricade of people or deer at 50+ mph. At 20 you might get away with it.

I was trying to think of a way to put that skillfully, and you did a good job.

I think there is a chance that some impacts with the stock bumper would just require replacement of the stock bumper. I wonder if the same impact with an aftermarket bumper would get other parts of the truck involved, that wouldn't have otherwise been damaged.

[RevolverRob]

I was trying to think of a way to put that skillfully, and you did a good job.

I think there is a chance that some impacts with the stock bumper would just require replacement of the stock bumper. I wonder if the same impact with an aftermarket bumper would get other parts of the truck involved, that wouldn't have otherwise been damaged.

It's possible. I simplified it overall. And the differences maybe so small as to not matter. Like hit that deer at 49 with the stock bumper airbags don't deploy, at 50 they do. With a steel bumper hitting the deer at 49 does result in airbag deployment.. ARB and Warrior Products both design and tests their bumpers to work well with the existing systems of the vehicle. So they tend to only make the vehicle a handful of percentage points more sensitive. But a lot of companies do not test their stuff at all.

The closer to stock weight the bumper is the less likely it is to cause a big difference.

Anyways with our modern vehicles we just have to be wise about our choices. If your vehicle lacks air bags and crumple zones. Then plate that thing up and go full kill dozer!

[rd62]

I wonder how an aluminum bjmper would react under similar situations. Would it be a sweet spot? Closer in weight to the original while providing additional protection? I've seen some outfits offering aluminum skids and bumpers. I've considered an aftermarket bumper for my Tacoma but would want it for additional protection against deer strike as I have no desire/intent at higher approach angles for rock crawling and I don't like the aesthetics of high clearance bumpers.

[El Cid]

As a spin-off of my IR driving lights thread…. Looking at bumpers and wonder if anyone has good or bad experiences with Hammerhead or Fab Fours in terms of quality or performance? I’m looking at the pre-runner styles but am more concerned with just overall reputation and durability. Thanks!

[farscott]

It has been thirty-plus years since I did a stint in Inflatable Restraints aka "air bags", but my fuzzy memory of some crash test results was that adding rigidity to a body-on-chassis vehicle had different results than adding rigidity to a unibody.

Another change is the modern modules have sensors much closer to the passengers than the original designs which put sensors on the radiator support and fender "shotgun inners". The original designs had five sensors (three primary and two secondary) and a bag deployment could not be commanded unless one primary and one secondary sensor closed from the impact. For the electrically-conversant, the three primary sensors were in parallel and the two secondary sensors were in parallel with the two sets in series. The original sensors were electromechanical, a rolling ball in a tube or a flat spring wound over a weight. The original requirement was a deployment was required with an offset front collision into a "standard wall" at any speed above 14mph. Any deployment at 14mph or lower was a failure. The low speed was due to the requirement to handle non-belted passengers as those people could move farther than a belted passenger. With the modern systems, a belted passenger is the assumption. Modern sensors are all silicon. So the speeds required for a frontal deployment are higher than those in 1990.

So it might be possible that a more rigid fascia (the bumper on modern vehicles is hidden under the decorative fascia) might not change the air bag characteristics too much. It is also possible that the attachment may bypass a crumple zone and make an accident more severe than it would be with the OEM bits at the same speed. It would take several million dollars and a lot of vehicles to know for sure.