Weight limit on rear bumper

[Bill]

We have a lot of posts regarding weight on the rear bumper - why is there a limit of 100 pounds, and what happens if I put on more?

I was just reading the RV Daily Tips. One of the articles (about carrying a generator) made a comment that may be applicable to us. It suggested that carrying a generator on the back bumper is a bad idea because as it bounces, it flexes the frame very slightly. As the frame flexes thousands of times, it tends to pull loose from the body.

I had never heard this, and TM doesn't say this, but if you put an extra-heavy weight back there, the flexing would obviously be greater. The frame wouldn't fail, but slowly pulling it away from the body isn't good, either. Could this be the reason for the limit? I don't know.

Thoughts?

Bill

[TrailManorMan]

My rear receiver is only bolted on and seems to work itself loose using a hitch hauler with less than 100 lbs.
Soon I will weld the receiver on for a stronger connection to the bumper. Never
thought about frame to unit separation.

I recall a member who had cracks in the rear frame from carrying a generator in the rear storage area. A overloaded receiver would create similar stresses.

[scrubjaysnest]

At a minimum I would think the bumper to frame welds might not like the flex.

[TrailManorMan]

Originally Posted by scrubjaysnest

At a minimum I would think the bumper to frame welds might not like the flex.

i'll let you know in a few years if welding liked the flex for my 76 lb load.

Originally Posted by Bill

...
It suggested that carrying a generator on the back bumper is a bad idea because as it bounces, it flexes the frame very slightly. As the frame flexes thousands of times, it tends to pull loose from the body.
...

Guess flexing can be an issue with any long, light-weight frame.

BAL/Norco makes light weight frames similar to Trailmanor's. They are distinctive with the cut-outs and thin walls. They are used by several light-weight trailer lines, but the max trailer length now seems to be about 28'.

They used to be used by Kodiak and others for longer trailers, but no more. One guy I talked to at a campground who had a long one (~30' ?) said that the flexing caused no end of problems with the shell and even the holding tanks. There's also some threads on rv.net about early BAL/Norco frame failure, in particular the long ones. Probably flexing was the cause there as well.

Personally, I would worry about even a 28' light weight frame flexing. We were looking at a very nice Lance 28' trailer with the light weight BAL/Norco frames. But it had a long slide out, which I can imagine would not handle frame flex very well.

And yes, bouncing 100-200# on the end of one of these light weight frames could definitely add more flex to what they already have. The Lance trailers do not allow any rear attachments for bikes and stuff, probably for that reason.

I've sort of come to the conclusion that our next trailer (yes, we're looking to "upgrade", the Elkmont is getting too small for our long stays in Florida) will have a solid beam frame with "over"-rated axles, wheel and tires. Just one less thing to worry about.

[TrailManorMan]

Seems the stress of a WDH would stress more....just thinking

Originally Posted by TrailManorMan

Seems the stress of a WDH would stress more....just thinking

Lance Trailers with the light weight BAL/Norco frames sets a max limit on WDH bars as well. Nothing over 1000# IIRC.

[TrailManorMan]

1000vs100 seems like WDH is more than a hitch haul stress ....
I carry a small patio mat , two chairs, weighed on my scale including the hitch haul and it doesn't weigh enough to be an issue.

thought I read on here TM changed the receiver because dealers were towing two TM's in tandem for delivery and had an accident, if TM was worried about frames wouldn't they just quit offering a hitch with any capacity?