Impact absorbing vs. non-impact absorbing bumper mounts?

[yubert]

I have an ARB front bumper on my D2 and recently had a minor front-end collision, no airbags deployed. However, the impact forced the front of the bumper down and pushed the side wings up and damaged the fenders.

ARB uses an impact absorbing bracket to attach the bumper to the frame. It's this impact absorbing bracket that caused the bumper to be pushed down.

The question I have is should I get new impact absorbing brackets from ARB or replace them with custom solid brackets? I asked ARB if they made solid brackets but they said the impact-absorbing design protects the frame. But the impact was so minor, I'm worried if I used a winch, it would tweak the bumper.

How do other manufacturers attach their bumpers to the frame? Do they attach to the aluminum crush cans or directly to the frame?

--Yubert

 

[jgdisco2]

my rovertym attaches directly to the frame, you also have to drill verticle holes into the frame for bolts which give it even more stability.

i know some arb owners have welded the crushcans somehow to make them stronger, idk what part they weld to what though just heard them talking about it

 

[fishEH]

I've often thought about this question. IMO, the need for a stout off road bumper out weighs the crush factor in an accident. I have a HiCountry front bumper and it bolts straight to the frame, no crush cans. I've nudged many a tree and rocks and other things and it hasn't budged. I also feel that if I'm in a small collision its the other guy that will get the raw end of the deal. If a collision is bad enough to tweak the frame using a non-crush bumper, than the collision was probably bad to total out the vehicle anyways. These things don't hold value that well.

 

[Bishops13]

http://www.expeditionportal.com/forum/showthread.php?t=14485

 

[yubert]

http://www.expeditionportal.com/forum/showthread.php?t=14485

Thanks for the link but I do have a weld bead on the backside of the crush cans. And from my recent experience, the concern about ARB bumpers "rolling up" is valid.

Seeing that Rovertym, HiCountry and Bottorf attach directly to the frame, I'll probably do the same.

 

[Snagger]

I would say the bumper design is the problem, not the crush cans. The bumper needs to have more clearance from the trim panel under the lights and needs to have its side returns removed. That way, the cans can do their job of saving the chassis without damaging the bodywork. That's why the original RRC and Discovery bumpers have steel main sections with separate plastic end caps which easily deform or disconnect from the body and bumper. ARB should have done the same.

However, it appears that the crush cans may be excessively weak - you still want them to be sacrificial, but not as easily distorted as that.

For what it's worth, the airbags should only deploy in a relatively heavy impact, and can't be used as a measurement of how much force was involved

 

[Paladin]

Interesting. And thanks for the very good photos. They highlight, I believe, another difference between the 03-04 ARB bumper design and the previous. I need to confirm this, but I believe it's true:

Not only does the 03-04 design have 2 vertical pinning bolts through the frame to prevent rotation, but they also enclosed the bottom of the crush cans. Yours appear to be totally open on the bottom. The newer model has a tab of metal on the bottom to help stabililize it. I'd have to get a picture.

I wonder if you could buy the 03-04 crush cans from ARB, and if they would fit.

What exactly was the impact? What did the other car look like?

 

[yubert]

I

I wonder if you could buy the 03-04 crush cans from ARB, and if they would fit.

What exactly was the impact? What did the other car look like?

Thanks, I'll check with ARB if the 03-04 crush cans will fit.

I rear-ended a Subaru Outback that was stopped at a red light. I slammed on the brakes but not in time to avoid an impact. I also didn't have a camera or cellphone with me to take any pictures.

The embarrassing part is it looked like I suffered more damage than the Subaru. There was 4 or 5 inch vertical cut in the center of the rear bumper's plastic cover, the latch/lock on the rear hatch was pushed in and the rear hatch was dented in. But there was no broken glass and the brake and turn signal lenses were not broken.

 

[Antichrist]

I've often thought about this question. IMO, the need for a stout off road bumper out weighs the crush factor in an accident.

The NHTSA requirements behind shock absorbing bumpers are only to reduce body damage during low speed impacts. We had shock absorbing bumpers here long before we had air-bags. Worst case, replacing one with a non-airbag compliant one is the likely hood of the air-bag deploying at a slightly slower speed. I wouldn't worry about chassis damage being significantly more likely.

 

[Paladin]

The embarrassing part is it looked like I suffered more damage than the Subaru. There was 4 or 5 inch vertical cut in the center of the rear bumper's plastic cover, the latch/lock on the rear hatch was pushed in and the rear hatch was dented in. But there was no broken glass and the brake and turn signal lenses were not broken.

I'm going to guess what happened is that his bumper under-rode your bumper mostly? His bumper only caught the bottom edge of yours, which combined with the weak design of those crush cans which seem designed specifically to do what they did...