Rear Bumper Build (First Time) (1 Viewer)

[albee]

It looks like you did a really nice job on the fabrication of your bumper, but you should consider starting over with thicker material.

When I made mine last year I used 4"x6"x3/16" so that I could recess my tail lights into the bumper. I did this for two reasons, it provided protection for them and gave me an opening to bolt it to the rear crossmember. Eight bolts were used to secure it, and on the back of the bumper spacers were welded where the bolts go through to clear the rivets.

Your 2" receiver could be extended through both sides of the bumper. I extended mine out the back the same distance as the spacers. This allowed it to be welded in the front and back making it much more secure.

I do not understand how the bumper will sit against the cruiser with the center latch plate hanging over the back. Can you weld a tab on the tire carrier, so the latch can be bolted to the bumper so as not to hang over the bumper.

Al

 

[firestopper]

From the pictures at the start of this thread, it looks to me you built this bumper and swing arms out of heavier material than 1/8 or 11 ga. The corners on the material have a decent radius indicating thicker stock.
Make sure! I have been fabricating for 30+ years and have seen many failures due to improper material selection.
I would NEVER consider any tubing other than "structural tubing" for this type of application.
Never less than 1/4" and pads,gussets where applicable.
Like toomanytoys said....You don't want to kill the family behind you when something goes south.
Also use the 4X4 labs swing kit and some sort of pad opposite of pivot to take up any play while in motion.
I like to use delrin for this as it serves both support with no squeak/rattle.
On the flip side, nice fab work.
Respectfully,
firestopper

 

[mrjay2u]

why do something twice.....spend once, and cry once...it that spare tire flies off your bumper and kills a Mom and her Baby due to inadaquate weight rating, you are liable....they sell the entire unit. Trailer axles are great if your gonna stay on pavement.....i did that about 15 years ago and it failed up in New Hampshire...

Take my word for it, do it correctly the first time, Here is the link

http://www.4x4labs.com/products/rear-bumpers/heavy-duty-spindles/

I have a spare tire, two tool boxes both about 55lbs a 5 gallon water and a 5 gallon fuel on one, a basket with a cooler, plus the weight of the frame......i weigh 240lbs and stood on the very end .....zero flex

i think i have some pics of it in my build post below. check it out

just trying to help.

X2 on the 4x4labs spindle. Very beefy, and granted I'm only swinging a 35" mud tire, and nothing else, but I wanted to be more safe than sorry.

Sent from Jay on a HTC Vivid using IH8MUD

 

[forestderp]

I also recently built a rear bumper for my cruiser, here are a couple pics.

I made these

I have 20 of the carrier housings sitting in a box.

 

[delmandi]

From the pictures at the start of this thread, it looks to me you built this bumper and swing arms out of heavier material than 1/8 or 11 ga. The corners on the material have a decent radius indicating thicker stock.
Make sure! I have been fabricating for 30+ years and have seen many failures due to improper material selection.
I would NEVER consider any tubing other than "structural tubing" for this type of application.
Never less than 1/4" and pads,gussets where applicable.
Like toomanytoys said....You don't want to kill the family behind you when something goes south.
Also use the 4X4 labs swing kit and some sort of pad opposite of pivot to take up any play while in motion.
I like to use delrin for this as it serves both support with no squeak/rattle.
On the flip side, nice fab work.
Respectfully,
firestopper

So even with the squared tubing doubled up like shown. The total length of each swing out would be less than 30". Are you still suggesting 1/4" wall tubing? I priced some at the local steel suppler and the price was almost double of 1/8' wall and they only had 24', that seems a bit more than I need.
I am open to any and all suggestions as this is my first build and want to do it correctly the first time and not have too much worry about things flying off! Thanks everyone for the inputs and suggestions.


IMG_0259 by mark.delgadillo, on Flickr

 

[lcwizard]

fire stomper and Mark are right. I would guess the first fail point to be the 3/4" bolt. All my carriers use
1 1/2" Ground and polished shafting. We've built over 1100 units with only one hinge post breaking and
that guy was rear ended by a Forest Service water truck during a fire fighting incident. The truck was so tall it hit dead center on the rim of the spare changing the backspace 3.5 to 6. Not knowing which side your putting the tire you could lower the tire center to about 14" off the top of the arm. The left appears to be about 26"~28" and the right, about 20". this would greatly reduce stress on your pivot points. I only use 1/4" wall tube but I have to fix anything that breaks and I tried .188 got more oscillation than I wanted.
In the 90's I built a couple .120 wall based units but the extra gusseting and reinforcement procedures made the carrier more work than it was worth. A second bonus of .250 is that even if moisture gets in the tubes it takes a hell of a long time to rust through

 

[delmandi]

fire stomper and Mark are right. I would guess the first fail point to be the 3/4" bolt. All my carriers use
1 1/2" Ground and polished shafting. We've built over 1100 units with only one hinge post breaking and
that guy was rear ended by a Forest Service water truck during a fire fighting incident. The truck was so tall it hit dead center on the rim of the spare changing the backspace 3.5 to 6. Not knowing which side your putting the tire you could lower the tire center to about 14" off the top of the arm. The left appears to be about 26"~28" and the right, about 20". this would greatly reduce stress on your pivot points. I only use 1/4" wall tube but I have to fix anything that breaks and I tried .188 got more oscillation than I wanted.
In the 90's I built a couple .120 wall based units but the extra gusseting and reinforcement procedures made the carrier more work than it was worth. A second bonus of .250 is that even if moisture gets in the tubes it takes a hell of a long time to rust through

Thanks, I appreciate the info! I am just starting to get into the fab stuff and just started welding a few months ago.

Is all square tubing of the same wall thickness going to have the same structural quality, ie: 1 1/2" 11gauge be as rigid or more rigid as 2" 11 gauge square?

And you mentioned lowering the tire center to 14", would I need to changed the distance out as well?

I had originally planned to mount on drivers side, visibility mainly, figured if it was directly behind me I wouldn't be as much of an obstruction.

Driver side swing out measures 27x22.5 and passenger 27x20.5

Thanks again all advice and suggestions are noted and appreciated!

 

[SAWTOOTH 55 LC]

Very nice! we think alike

 

[lcwizard]

Your tire plate will have to clear the offset of the rim. Having the bottom of the tire push up against the
swing arm will help stabilize the tire. Our upright post is 12.5" with a 10 deg cut to cant the tire plate forward. You can leave the upright straight but then the tire plate just needs to extend farther out.
Weld points can only be as strong as the base metal. I doubt your welds will fail but the metal may fail where the weld stops. Your greatest stress will be where the hinge meets the arm and obviously where the pivot bolt meets the mainframe. You can support the point where the arm welds to the hinge tube
by wrapping 2 1/2" or 3" strap around the hinge tube and forward on each side to where the three tubes converge. As for the pivot pin itself, you could, as a previous poster suggested, build a plate that bolts to the outside that puts the pin into a double shear set up, supported at two points rather than one. Fish plating, with gussets over critical butt welds will help preserve weld joints. Lastly I guess would be to keep an eye on the bearings. I'm familiar with that radial bearing. They are generally used as axle bearings in wheelbarrows and wagons. That particular bearing works perfect as a support bearing in a cruiser steering column when doing a power steering conversion. The cruiser steering shaft is 3/4" and the steering tube ID is 1 3/8". Radial bearings aren't designed to have preload forces on them so don't
tighten the nut excessively.
Like I mentioned earlier it's easier to use the heavy wall tube. It requires less engineering

 

[mrjay2u]

Have you looked at comp4x4.com?
I thought I had the 4x4labs spindle, but thumbing thru receipts said otherwise. Greasable bearings a plus.

Sent from Jay on a HTC Vivid using IH8MUD

 

[delmandi]

There are quite a few different options to go with, I just have the decision to make on which one to go with!? I hate these decisions, as I know the majority of the spindle kits I am looking at are good quality and similarly priced, I am just very indecisive when it comes to this kind of stuff.

Should have seen me shopping for my welder, took me three months to decide on my hobart!

 

[TLC76]

I just checked mine, I used 4x3x3/16" for the bumper, and 2x3 and 2x2 1/8" for the tire carrier. No issues with it so far and I am not gentle (other than the snapped spindle).

 

[delmandi]

*update*

So after all the suggestions I have started over, sort of.

I got approval from the bank(wife) to buy a plasma cutter! (front bumper build will be next)
So as soon as that gets here I will cut the receiver out and weld all the way through. As well as cut out holes for tail lights, so they will be recessed.

Waiting on spindle kits, I'm going with these from comp 4x4.
http://www.comp4x4.com/Tire-Carrier-Hinge-Kit-Standard-Duty-1-1-4-Spindle.html
I am going with the smaller of the two as I don't think I will have enough space in the main bumper channel to fit the larger spindle.
Am also going to order these to use as a stop.
http://www.comp4x4.com/1-2-Diameter-Pop-Pin-with-T-Handle.html

I finally got to the metal shop and picked up a stick of 1 1/2" square 3/16" wall to make the swing outs with.

What its supposed to look like.


IMG_0342 by mark.delgadillo, on Flickr

Got the cooler/jerry can swing out almost done.


IMG_0339 by mark.delgadillo, on Flickr

IMG_0345 by mark.delgadillo, on Flickr

Tire carrier assembled.
Top support is tacked on as I am not positive on the length yet, now its 6" out, debating if I want to be able to have the spare touching the actual bumper to help steady the load.


IMG_0347 by mark.delgadillo, on Flickr

and I AM OPEN TO SUGGESTIONS and advice! I do only want to do this once(well twice now). Well mount to the little red once! and be safe. Thanks.

-Mark

 

[TLC76]

On mine I had the spare press against the mount a bit just to add some stability.

 

[rmckay1021]

Great bumper build thread! Any progress lately?

 

[delmandi]

Recent progress!

Received my spindles and pop pins from comp 4x4(www.comp4x4.com) Great company I called with some questions and were great on shipping. I went with these because they came with a sleeve to set weld into the bumper rather than the spindle. I just tacked the spindle into the sleeve to mount them.


IMG_0517 by mark.delgadillo, on Flickr

IMG_0514 by mark.delgadillo, on Flickr

Finally got my plasma cutter so I cut out the receiver hitch and mounted all the way through the bumper.


IMG_0525 by mark.delgadillo, on Flickr

IMG_0524 by mark.delgadillo, on Flickr

I had to flatten out the sides of the sleeves to fit inside the bumper channel as they were a little over 1 1/2 wide. (2" wide 1/4" wall bumper channel)


IMG_0520 by mark.delgadillo, on Flickr

Then mounted the spindles.


IMG_0526 by mark.delgadillo, on Flickr

IMG_0530 by mark.delgadillo, on Flickr

Should be able to get everything finished up this weekend!!! hopefully!
Just cant decide on lights!?? I am going to be putting LED's just cant decide on round or oval, the ones with rubber ring that snap in or screw in kind( I can tap some holed on the 1/4" wall pretty easily)

 

[ElHefe]

Looking great. Glad you upgraded the spindles.

 

[camcruiser13]

Do I understand correctly... you made your bumper out of 1/8 inch steel and your tire carrier out of eleven gauge?

If so it is time to start over.

A bumper and tire carrier built with material that light will NOT survive on the trail. Even on the street is likely that the tire carrier will eventually fatigue the bumper material where it is attached and tear loose.

Mark...

I also read that and winced but then noticed in the pic it looked a lot thicker than 1/8 inch tubing

That bolt crap you have will fail with any weight on it. Do it right one time. If you trying to get the nut off broke the bolt I think that is enough evidence. I don't want to be behind you when that tire falls off and kills me and my passengers. Just saying

 

[camcruiser13]

Ok so I'm the idiot. Didn't even notice there was a page two.


I forgive you

 

[delmandi]

I also read that and winced but then noticed in the pic it looked a lot thicker than 1/8 inch tubing

That bolt crap you have will fail with any weight on it. Do it right one time. If you trying to get the nut off broke the bolt I think that is enough evidence. I don't want to be behind you when that tire falls off and kills me and my passengers. Just saying

yeah, i headed the warning, especially after the bolt broke! these spindles seem pretty stout plus I wont be submitting them to crazy heat by welding them into the bumper completely I hope they will be a lot stronger. oh, and the swing outs are 3/16" wall square now.