bumper question

[Kubla]

not sure where to put this, but is the back bumper on a school bus strong enough to support a rack holding 1000 pounds bolted to it or should I bolt the brackets to teh bolts that hold bumper?

 

[nat_ster]

not sure where to put this, but is the back bumper on a school bus strong enough to support a rack holding 1000 pounds bolted to it or should I bolt the brackets to teh bolts that hold bumper?

In short yes, but more info would be good.

Nat

 

[bansil]

Bumper is 3/16 or 1/4 formed steel, limiting factor would be the bolts shearing on the frame side where it's bolted, due to vibration or impact from bouncing

If mounts can move up or down, due to loose/clearance holes for bolts or rust between mounts (crumbling out, causing loose bolts) they can shear bolts like a pair of scissors

What is application?

Mounting hardware and mounts themselves would be the limit, I think

 

[bansil]

If you bolt anything to the bumper, the 2 feet of leverage on frame bolts is were issues would arise

 

[Kubla]

want to put a motorcycle carrier on the back
also need to eventually put a trailer hitch on it

 

[Hank's P-O-S]

Ideally you would bolt anything directly to the frame with grade 8 bolts and washers.
School bus bumpers are supposedly designed to be strong enought to lift the bus. This is for if it ever needs to be towed.
So yeah, it could probably take 1000 lbs. the issue is that it was built to take impacts and vertical force. It was not designed to have a "twisting" force or pulling force like a rack would put on it.
It probably would work... The issue I think would be it sagging and twisting over time and eventually failing.
I saw a picture a while ago of someone who bolted a pintle hitch on to it without modifications. The bumper pulled out as it was not designed to take force in that direction.

Attached is the picture I'm talking about...

 

[taskswap]

...

I can't even...

Did that even work ONCE?

 

[nat_ster]

Lol, nice.

To bend like that the bumper mounting bolts had to have failed, or the frame rails bent together.

Nat

 

[Kubla]

new plan is to get longer all thread grade 8 bolts, install them from the frame out so the bolt thread sticks out of the bumper, use the first nut to hold the bumper on then put the bracket on and use a second nut to hold the bracket so the load is transferred to the frame, not the bumper

 

[Crazy]

I like the way they extended the bumper so the pintle would be closer to the trailer.

 

[Vlad-SKO]

I can't even imagine to bolt a hitch directly to the bumper to tow or carry something. It is so much thick nice beefy steel around. It is really easy to make receiver and use it for years without thinking about loosing your goods during your trips. Just think what will happen if you drop your bike on interstate driving 60 mpg?????

Here is how another skoolie fellow solved this problem. Just scroll the page and see how. Looks good.... solid....:


http://www.skoolie.net/forums/f11/the-broccoli-bus-9394-38.html#post104205

 

[nat_ster]

If I was to bolt anything to heavy to the bumper, I would add a few more mounting bolts to the frame, and weld more ribs into the back of the bumper.

Not all bumpers are the same.

The 96 rear engine Blue bird only has one rear bumper.

The 2000 of the same bus has a sub bumper behind the outer bumper.

Nat

 

[nat_ster]

My bad, the 2000 rear engine with a sub bumper is a Thomas, not a Blue Bird.

So many buses here I'm loosing track.

I just looked at three 2001 rear engine Blue Birds. None of them have a sub bumper.

Nat