Rear Bumper that can be "bumped" while wheeling (1 Viewer)

[Randy88FJ62]

Theorizing how to design / build my rear bumper.

Features must include:
-tire carrier
-2 fuel,1 water can carrier
-2 inch receiver hitch
-2 recovery points

And last, be able to withstand a push or bump from another truck behind.

This last requirement has me thinking hard. Do you have something sit out further from the bumper like two rubber stops? Do I reinforce the tire / fuel can swing outs?

Or should I not worry about such a thing?

 

[Stumpalama]

Your last thought.

 

[brokeassyota]

Overthinking it.
Adam G

 

[Randy88FJ62]

I'm an engineer. Overthinking it is what I do best. That's how the TV remote got invented.

 

[Cruiserdrew]

Sounds like you want one of 4x4 Labs kits. It has everything you want and you get to build it yourself.

But why are you worried about a truck bashing you from behind?

 

[LandCruiserPhil]

Sounds like you want one of 4x4 Labs kits. It has everything you want and you get to build it yourself.

But why are you worried about a truck bashing you from behind?

^This^

 

[GLTHFJ60]

But why are you worried about a truck bashing you from behind?

Same thought here, unless you drive in an area where people regularly rear-end you.

 

[Randy88FJ62]

I am not expecting to be bashed from behind. I went snow wheeling this past Saturday in the local mountains. I can forsee a truck behind following too close or not being able to stop in time if I stopped fast. I was thinking it would be nice to have a bumper that could take a small nudge without bending the tire carrier or gas can basket.

This could also be translated to on road driving. If someone were to lightly rear end me I don't want to deal with having to re straighten my spare tire carrier and jerry can basket. It seems like a PITA.

 

[Enigma]

I have yet to be hit from behind on my 80 series, but I have bashed the literal crap out of the custom rear bumper on ledges/rocks/etc. I did back into a light post once though....that poor light post didn't know what hit it.
If I was to get hit in the back, the swing outs could probably be bent, but they are easily replaced just by the nature of the spindle assembly they are on. Could easily withstand some somewhat gentle nudging if one needed a push from another vehicle.
See sig for link to the awesome fab skills of the armour crafter.

 

[Mace]

If you build your bumper strong enough to take a big hit from behind, your frame will bend instead..

 

[Bret]

I have nudged a fellow wheeler stuck on a dirt hill, just bumped the spare tire, he had the carrier tied into the bumper and exo, the stinger just rested against the edge of the tire for the push. Once in over 12 years, and just because we were too lazy to get out and hook a strap. I would think if you built it to handle the load from an oversized tire without bending, shaking etc. it could handle a little pressure. Would be better with good recovery points on all 4 corners.

 

[BionicCruiser]

on a snow run, I rear ended a lexus 450. completely missed the bumper and caved in his tail gate with my super high FJ40 bumper (mid thigh high). bumper made no difference...

 

[Cruisin']

If you get hit from behind by another truck, the swingouts will probably take some damage. Not much way around that, but fairly easily fixed. If you get rear ended by a car, you'll be fine as most cars will go under the tire/fuel cans/whatever you've got on there, and will hit the bumper itself. A stout bumper will shrug it off like it never happened.

 

[Corbet]

Yah, you'll be pretty hard pressed to not have your spare be the initial point of contact from another trail rig. And no swing arm will take that kind of abuse without some damage. I second the 4x4 labs. If a car rear ends me I'm more worried about my rear axle as that will probably be the first thing that really takes a hit.

I had a BMW go under my FJ40 years ago. The shackles peeled back his hood and his bumper hit my axle housing. BMW did not fair well. I drove home with a broken tail light lens and his insurance info.

 

[cody c]

Perhaps think about building it so that the lower part of the spare tire on the swingout is the point of contact, and that the tire is against the bumper, in other words, person pushes tire which is pressed against the bumper. Having over-sized tires may be optimal for this.

The only con to this is that moving the spare lower effects your departure angle negatively, you may just want some of the rubber bumpers that you see on semi trailers for this, or travel at the back of the pack.

I pondered the same thing a long while back.

The only other thing I could think of would be a major undertaking, cutting out your rear cross member and making a new one below, mounting your spare so it slides in between the frame rails, and putting your extra fuel containers up high or else where, then building your bumper around it.

Kind of like this picture without the bar around it, and having the tire stick out a few inches more:

 

[NCFJ]

I think that you are over thinking the issue. Build the bumper tough so that it can handle being an impact point on the bottom of the bumper as the rub point on the departure angle. If you wheel it you will drag that bumper far more than you'll ever use it as a push bar.

I have dropped my FJC directly on my rear bumper while coming down "steps" and suspended the rig, rear tires in the air, directly on the bumper. The only damage was to the paint. This is what you want to build for. You also want stout protection on the corner and the sides up to the rear tire. Tie the sides back to the sides of the frame.

Good luck with your build

 

[dbleon]

If you build your bumper strong enough to take a big hit from behind, your frame will bend instead..

+1... ask why the factoty made flimsy bumpers = maybe to bend first and therefore save the frame.

You is smart MACE