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Started by gawin, March 17, 2016, 02:13:17 PM

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popup2012

Interesting note on hitches on the rear bumper.  On Aliners (popup trailers), they all used to come with a trailer hitch on the rear bumper. They said you could put a couple of bikes back there.   NO More.
Reason: too many rear bumper coming off causing too many complains. This caused  the lawyers for the company to say we have  too much liability.  They still come with the spare tire on the rear bumper but here at the dealer in Austin,TX  I saw a 2 month old camper where the spare tire movement had damaged the rear of the camper. Even this had twisted the rear bumper and the whole back of the camper had to be replaced.     We got this info  at a  campout from the factory rep in NC.

admin

I am not an engineer so I don't pretend to know the actual stress values at play here, but I do have a combination of other experiences that helped guide my thought process. I know that any load or force when given the right leverage will be multiplied. The question is by what factor is the load multiplied? I know that placing a weight at about 90 degrees to the bumper out on a lever and then bouncing it up and down as we head down the road is simply asking for trouble if the bumper is not ready for the stress. I remember teaching students about rock climbing and explaining that an average sized person can exert a couple thousand pounds of force on an anchor during a fall. I can only imagine what a 150 or 200 pounds would do to a bumper given the right leverage.

With that in mind that is why I reinforced my bumper to give it the most possible stress while passing as much load as possible to the frame rails. Physics make my head hurt sometimes so in my humble opinion its easier to over build and overestimate the forces at play than to deal with the repair costs.

charliem

[quote source="/post/22925/thread" timestamp="1468253719" author="@admin"]I am not an engineer.........so in my humble opinion its easier to over build and overestimate the forces at play than to deal with the repair costs.[/quote][font size="3"]Well, I am an engineer and truer words were never spoken. And add to that the inconvenience. Ralph Murphy's law #17.5 states any failure will occur at the most inconvenient time and do the most possible damage.  [/font]
Any 20 minute job can be stretched
to a week with proper planning

Charlie
NW Florida

idaho

We had this mod done at a local aluminum utility trailer manufacturer:

[attachment id="1561" thumbnail="1"]

pinstriper

I think the engineers talk about static load and dynamic load when describing this.
Let's eat, Grandma !
Let's eat Grandma !
Punctuation. It saves lives.

2014 14DBS
2013 4Runner | 2006 F-150 5.4 V8 (ruh ruh ruh)
2015 Hobie Outback

mbanks

Quote from: @pinstriper" source="/post/22936/thread" timestamp="1468264709I think the engineers talk about static load and dynamic load when describing this.



Nice! How much did it cost you?

pinstriper

[quote source="/post/24261/thread" timestamp="1472441003" author="@gregcolumbus"]
Quote from: @pinstriper" source="/post/22936/thread" timestamp="1468264709I think the engineers talk about static load and dynamic load when describing this.

Nice! How much did it cost you?
[/quote]8pm
Let's eat, Grandma !
Let's eat Grandma !
Punctuation. It saves lives.

2014 14DBS
2013 4Runner | 2006 F-150 5.4 V8 (ruh ruh ruh)
2015 Hobie Outback

mbanks

Sorry, i meant to ask Idaho...

gmcspad13

[quote source="/post/22823/thread" author="@mtnbikr" timestamp="1467843053"]How about this?  :)  

[/quote]Did you have that fabricated? How much did it end up costing?