Bumper Receiver

[Homersimpson]

All this is for bike racks, which extend from the back bumper. Related question: can the stock bumper handle two spare tires? Based on the dire warnings offered above, I am surprised that the bumper can hold even one spare tire, let alone two.

[rockfordroo]

Originally Posted by Homersimpson

All this is for bike racks, which extend from the back bumper. Related question: can the stock bumper handle two spare tires? Based on the dire warnings offered above, I am surprised that the bumper can hold even one spare tire, let alone two.

Your bumper can probably handle 2 spares. The big problem with stock bumpers and bike racks is that the rack puts the weight of the bikes at the end of a very long lever, the distance from the bumper to the bikes. It can be 2-3 ft on some racks. This creates a LOT of stress on the fairly thin weld between the frame and the bumper. The spare tire holders are typically on the order of an inch or two of leverage.

But use the Safety Struts (link in Post #20) and you definitely won't have an issue with 2 spares.

[BigLou80]

I plan on installing a receiver on my bumper this week, pics to follow shortly my plan is to bolt ( sandwich) some 4"x3/16"( because I have some) by approx 6'-7' plate on top of the existing bumper extending out to at least the frame connection points. . To this plate of steel I plan on welding a 2" receiver. This should prevent any point loads on the center of the bumper where I want to mount it and make for an easy seamless removal when I want to trade the trailer in. Or I'm just going to cut the existing bumper off and weld on a thicker tube.... pics possibly later today

[rockfordroo]

Originally Posted by BigLou80

I plan on installing a receiver on my bumper this week, pics to follow shortly my plan is to bolt ( sandwich) some 4"x3/16"( because I have some) by approx 6'-7' plate on top of the existing bumper extending out to at least the frame connection points. . To this plate of steel I plan on welding a 2" receiver. This should prevent any point loads on the center of the bumper where I want to mount it and make for an easy seamless removal when I want to trade the trailer in. Or I'm just going to cut the existing bumper off and weld on a thicker tube.... pics possibly later today

It's not usually the bumper tube that fails. Its the two skinny welds at each end, between the web and flange of the frame and the bumper tube. As I stated in Post #22, it's the leverage issue of the weight of the bike rack trying to rotate the bumper down and away from the frame. The stress fails the welds at the frame and the bumper falls off.


That's why the Safety Struts seem to work. They take the rotational force and transfer it to the frame rather than the weld.

So I don't think your plan is a good one. Now if you offset your 4" plate so you had 2 inches over the bumper and 2 inches forward over the frame web, and then welded the plate to both the frame web and the tube, you'd be a lot better off.

See attached.

[rsdata]

Those bumper failures did not have the added mount n lock struts. If you have heard of failures after that install I would love to read them so I can make an educated decision on the struts.

Well I tried to find a story about a mount n lock failure, but was unable to do so... not that there is not one or more out there... BUT if someone did have a failure with a reinforced bumper I'm sure they would have posted here or on amazon at the very least.

And I will add again, that reinforcing the bumper is not a cure all for any stupid thing that you want to add to your bumper... I always say that firewood and generators should never go on a LIGHTLY MODIFIED bumper, and keeping things close to the bumper instead of hanging way off the bumper tube is a problem when any significant weight is involved.

[wildcatter]

Originally Posted by rsdata

Well I tried to find a story about a mount n lock failure, but was unable to do so... not that there is not one or more out there... BUT if someone did have a failure with a reinforced bumper I'm sure they would have posted here or on amazon at the very least.

And I will add again, that reinforcing the bumper is not a cure all for any stupid thing that you want to add to your bumper... I always say that firewood and generators should never go on a LIGHTLY MODIFIED bumper, and keeping things close to the bumper instead of hanging way off the bumper tube is a problem when any significant weight is involved.

There are several on you tube, here is one.

https://www.youtube.com/watch?v=YIwtglKiBwk

[rsdata]

wildcatter...

this is what I said and that video does not fit what I SAID...

Well I tried to find a story about a mount n lock failure, but was unable to do so...

[Ron045]

+1 rsdata. You beat me to it. Watched the video and did not see the SS installed either.

[rockfordroo]

Originally Posted by Ron045

+1 rsdata. You beat me to it. Watched the video and did not see the SS installed either.

X2 (Or is it X3?)

[itat]

rockfordroo, when the non-reinforced bumper (i.e. no Mount-n-Lock Safety Struts installed) fails, I think the typical failure mode is the thin bumper metal that tears where its welded to the frame. Is that correct? The Safety Struts prevent the bumper from twisting under the load of the bouncing bikes (at least at the weld points) and thereby prevents the bumper from tearing at the frame weld.

[rockfordroo]

Originally Posted by itat

rockfordroo, when the non-reinforced bumper (i.e. no Mount-n-Locks installed) fails, I think the typical failure mode is the thin bumper metal that tears where its welded to the frame. Is that correct? The Mount-n-Lock supports prevent the bumper from twisting under the load of the bouncing bikes (at least at the weld points) and thereby prevents the bumper from tearing at the frame weld.

Correct.

[wildcatter]

Originally Posted by rockfordroo

X2 (Or is it X3?)

Sorry, I missed read the post, I thought you were looking for a story on bumper failures, I should learn to read and comprehend better.

[JohnD10]

Originally Posted by cpd1343

It is not a "bumper". It is a storage tube. It is not meant for anything other than that. The limit is the spare tire mount. Anything other than that is a gamble.

That is not necessarily true...

Some bumpers are made for some extra weight...some aren't!

What you need to do is call Forest River with your Vin# in hand and ask them what the bumper rating for your exact trailer is.

My 5'ver (not a FR) has a 4x4 tube rear bumper, but it is rated to handle the flip-down cargo rack, which I chose not to get.

[rsdata]

JohnD10

My 5'ver (not a FR) has a 4x4 tube rear bumper, but it is rated to handle the flip-down cargo rack, which I chose not to get.

This discussion started on and is posted on the Roo/Shamrock hybrid forum which DO have the light weight bumpers...

What you need to do is call Forest River with your Vin# in hand and ask them what the bumper rating for your exact trailer is.

And I'm sure FR will give a CYA answer like "nothing more than what it came from the factory with".

[doc73]

I have the safety struts and a bolt on receiver just like the one you posted. Between two trailers it have been used without incident for 20k miles or so.

[BigLou80]

Thanks for clearing that up Rockfordroo. I decided not to go with my original plan as a result. I welded some angle iron on to the bottom of the bumper and the frame and the bumper is now welded to the frame in several spots. I.may add additional gussetts where the top of the bumper meets the frame but the factory welds looked solid total investment $15 in steel and 2 hours

[pbrackney]

Originally Posted by rsdata

Well I tried to find a story about a mount n lock failure, but was unable to do so... not that there is not one or more out there... BUT if someone did have a failure with a reinforced bumper I'm sure they would have posted here or on amazon at the very least.



And I will add again, that reinforcing the bumper is not a cure all for any stupid thing that you want to add to your bumper... I always say that firewood and generators should never go on a LIGHTLY MODIFIED bumper, and keeping things close to the bumper instead of hanging way off the bumper tube is a problem when any significant weight is involved.

Yes my findings have been the same. So I’m going to try out the struts and add an aluminum cargo carrier that weighs 17 pounds and carry 3 inflatable 2 person kayaks with the carrier. I have also removed my spare tire from the bumper and installed the Bal Hide a Spare underneath the travel trailer.

http://norcoind.com/bal/products/con...-a-spare.shtml

[Lukegsdaddy]

Ok. Our 26dbh came with one of those cargo baskets with the spare tire attached stating nothing over 250#s to be attached.

What is the difference with this weight VS a bike rack with 2 or 4 bikes not even coming close to 250#s?

Thanks.

[doc73]

Bikes may only way 40lbs total but when on a bike carrier they bounce. This doubles if not 4x the load as they bounce down the road on the end of a big lever,prying on the welds. Those 40lbs of bikes are now 300lbs of bike at the welds.

[rockfordroo]

Originally Posted by BigLou80

Thanks for clearing that up Rockfordroo. I decided not to go with my original plan as a result. I welded some angle iron on to the bottom of the bumper and the frame and the bumper is now welded to the frame in several spots. I.may add additional gussetts where the top of the bumper meets the frame but the factory welds looked solid total investment $15 in steel and 2 hours

Support at the bottom should help prevent rotation, but you also might want to weld a plate across the top of the bumper and the top flange of the frame. It will start to separate at the top, not the bottom.