Weight capacity for TT bumper

[saintsfanfl]

I have a 2005 Starcraft Homestead 24RKS and the bumper appears to be heavy duty 4 inch and welded to the frame. Does anyone know the average weight capacity of something like this? I saw another Starcraft with a similar setup and they had the hitch that bolts to the bumper. I was going to order the same thing and use a hitch rack that my generator will go on. The generator is only about 90 pounds and the rack maybe 50 or so. I would think the bumper could easily hold 500 pounds but I wanted opinions first.

[Acdii]

GrandpaKip wrote:
The steel bumper on ours is less than 1/16th". That's why I modified a 24x60 cargo carrier to mount to the frame between the body and the bumper. It holds the spare, a bike, the sewer tote and the patio mat. There is a 1/8" gap between the carrier and the bumper, so the bumper doesn't carry any weight. I also put the mount-n-locks on just in case.

There is a saying, a picture is worth a 1000 words. This I would like to see.

[GrandpaKip]

TomG2 wrote:
There are spare tires scattered every two miles along the Interstate from RV bumpers. NOT.

That is correct. What convinced me not to put anything other than the spare on it was seeing a TT go slow over a speed bump with 3 bikes on a rack attached to the bumper. The resulting sway action was almost unbelievable. Yeah, they might have been doing that for years. Or not. Why take the chance?

[GrandpaKip]

The steel bumper on ours is less than 1/16th". That's why I modified a 24x60 cargo carrier to mount to the frame between the body and the bumper. It holds the spare, a bike, the sewer tote and the patio mat. There is a 1/8" gap between the carrier and the bumper, so the bumper doesn't carry any weight. I also put the mount-n-locks on just in case.

[Gdetrailer]

TomG2 wrote:
There are spare tires scattered every two miles along the Interstate from RV bumpers. NOT.

You might not see tires, BUT I can tell you this, BICYCLES DO AND HAVE BEEN "scattered" more than once on the roads..

I AM an official member of the bicycle tearing the bumper off club..

I was LUCKY to have discovered my bumper WAS indeed separating from the trailer.. I was 800 miles from home..

I do not recommend it unless you do not care for your fellow motorists or your bicycles.

Not really a funny subject, especially when it happens to you.

[Campfire_Time]

Check your owners manual. There should be something in there about the rear bumper. Mine specifically says not to mount anything on my rear bumper.

[TomG2]

There are spare tires scattered every two miles along the Interstate from RV bumpers. NOT.

[SoCalDesertRid1]

I weld hitches to the back of RV trailers and motorhomes whenever the job comes up.

What I do is cut off the thin factory bumper and throw it away. Then I fabricate a new bumper with receiver hitch built in, using 4x4x1/4 or 4x4x3/16 structural square tube, depending on the weight desired to be carried. I use 1/4" plate to weld to both the trailer frame channel or i-beam webs, and the square tube, as well as weld the channel or i-beam to the tube, all the way around. I also add a 1/4" thick gusset over the top weld to keep the thin trailer frame from starting a tear at the top.

This method works good. No customer has ever called me saying their bumper/hitch fell off and I've been doing this for years now.

Disclaimer-

I am a licensed welding shop owner and AWS certified structural welder, with liability insurance. If you don't truly know what you're doing, DON'T DO IT. Leave it to the professionals.

[jaycocreek]

My trailer came with a warning stick on the bumper that said the max weight was 135 lbs. The bumper can support much more than that, I know because I've stood and bounced on it. However the manufacturer is accounting for the hammering effect.

Sounds about right.I have never had a bumper fail with just the spare tire mounted but when I carry a generator and extra's,I use a hitch haul that is mounted to the frame, and most all of my adventures are off road.

[Community Alumni]

The problem with most stock bumpers are that they aren't substantial enough to place heavy object back there. While they can support the static weight of the objects, they also have to support the dynamic weight of the objects bouncing around. You end up with a very effective hammer back there. My trailer came with a warning stick on the bumper that said the max weight was 135 lbs. The bumper can support much more than that, I know because I've stood and bounced on it. However the manufacturer is accounting for the hammering effect.

[Acdii]

stevemorris wrote:
I worry about those spare tyre carriers bolted to the bumpers, got rid of mine
spare is in the pass thru

If you bolt the carrier around the frame attachment point, then the chances of it failing are very very low. Also the type of carrier makes a big difference. The short ones that put the tire a couple inches away and near center of the bumper are the best. Those that are hinged and sit the tire high are the ones not to use, they would stress the heck out of the bumper.

I had a few ideas on my way home from work (hour fifteen drive gives lots of thought time), and was thinking that a rack mounted on top of the bumper, close to the back wall would work to have a stable load to mount a generator back there as it wouldnt be leveraged out, so when I got home I measured my generator, then went back to the trailer and found, eh, wont work either, bumper is too close to the wall, the generator is 18" wide, so 2/3rds would overhang the bumper. Even though the mass would be low on the bumper, it would also be cantilevered out too much to be safe, so nixed that idea as well.

I also took another look at the attachment points. There are 1/8" angles welded to the frame and the bumper. They are well done, but as mentioned before, the wall thickness is too thin to support much weight. I was going to mount a truck box back there, even installed a bolt on receiver, but after looking everything over, decided not too, that and it would block the water heater outlet.

Bottom line, to brace the bumper to be strong enough to support overhanging leverage would add too much weight to the trailer, and a ton of work to make it strong. Not worth it.

[stevemorris]

I worry about those spare tyre carriers bolted to the bumpers, got rid of mine
spare is in the pass thru

[Gdetrailer]

Acdii wrote:

snip..

Here is the real problem, the wall thickness of the bumper is thin, even with a perfect weld to the frame, given enough trouncing, eventually the metal around the weld will tear, and cause the bumper to fail.

^^^^THIS^^^^ IS THE PROBLEM!!!

I almost lost two bikes not realizing just how thin the bumper metal is!

MOST RV bumpers are 14 gauge steel (about 1/16" thick), that is only a couple gauge sizes thicker than the sheet metal of a vehicles door skin (typical automotive sheet metal is 18 gauge!).

The 14 ga steel will simply tear away from the welds when it is twisted (which is what happens when you put bike racks on the bumper).

This leads to the fact that MOST RV bumpers do not have ANY weight rating for the bumpers..

SOME RVs do use a thicker wall bumper which will be 1/8" inch thick, with those the manufacturer of the RV will typically give a weight rating..

No weight rating from the RV manufacturer, do not attempt to put any weight on the bumper..

[Acdii]

There are two options for this if you truly want to use the bumper to carry something. The first option is a pair of these.
The second option requires some fabrication with materials you can get at any home center. You get some 2" angle iron, grade 8 bolts, 1 1/2" long by 5/8" diameter, washers, lock washers, and nuts. These are used to secure the angle to the frame, one on each side. You get a 4x4 to slip inside at each frame member, a piece of 3/16 plate, or cut the angle in half to place against the face of the bumper and then get 5" long grade 8 5/8" bolts, drill all the way through the bumper, 4x4, and angle, and secure them with washers, lock washers and nuts. You can use grade 5 bolts if you like, I prefer grade 8 for heavy duty things like this, I replaced the hardware on my Husky WDH with grade 8.

Neither fix will be as strong as a purpose built frame attached hitch as previously posted, but will support loads under 200# hanging off the back end. The former I was going to do, but thankfully looked at the actual attachment points and realized they would never work since my stabilizers are against the bumper, but option #2 would work fine, in fact I was looking around and found that I have 3" x 3/16" angle in my garage that would work fine, and since my stink pipe wont fit in the bumper, it is no loss of room for me, I have my hose in its own container that is sealed. That frame attached hitch wont work on my trailer, due to the stabilizer position.

Here is the real problem, the wall thickness of the bumper is thin, even with a perfect weld to the frame, given enough trouncing, eventually the metal around the weld will tear, and cause the bumper to fail. By using the plates, blocks, bolts and angle you can secure the bumper front the back, or back to front depending on how you look at it, and that weight then is transferred to the frame. Instead of a few welds, you would have 12 heavy bolts securing the bumper to the frame. While not perfect, it would be a whole lot safer than just putting the receiver on the bumper and hoping for the best.

[APT]

Lots of people do it. There is no standard for RV bumpers, so it is difficult for us to say you will have no problems. My advise is only put items on that bumper you are willing to lose.

Something that attaches to the frame would be better.

[saintsfanfl]

You guys convinced me. I cancelled the bumper mount hitch order.

The portable generator I bought is only 1 inch too tall to fit in the pass through. It would be nice to get it in there but not sure I want to modify the handles to make it fit. I will look at options.