Bike rack on rear bumper

You can do all the welding, bolting and reinforcing you want. if you don`t stabilize it with the trailer it will fail. you need to stop the bouncing back there. which is what I did, works great!

Personally, I've always had Jaycos and even used the one shown that went around the spare.
Currently our spare is under the trailer and we use a bumper mount with a bolt on receiver. The rack and the bikes are not close to what a spare would weigh and I do bungee the rack to the ladder. We use a Swagman that is designed for trailers.
Never had a problem in over 140,000 miles of towing all over the USA

No offense, But I'd NEVER do what you did..

I wouldn't be surprised if you end up with a bunch of holes in your trailer in a year or two, from the eyebolts pulling out.

Its a very bandaide solution, instead of actually fixing the issue.

A bigger issue (for me) is not seeing the bikes. Basically, when they do fall off, you won't know, you'll just keep on dragging them. And yes, I have seen this, and informed the RV driver.

this is how I stop bikes bouncing on the rear of the trailer.

My understanding is that if you make any mods to the frame, including welding a receiver or rack, it voids the warranty. If yours is still under warranty, I'd try to come up with Plan B.

Define safe???

Safe as stated in you question is ambiguous at best…

The true answer to what you want to know is not the answer people want to hear so the true answer is also a unpopular one…

If the bumper welds hold but the rack itself breaks from the bouncing, is that safe???
If the welds hold but your frame rails lose their camber to outright bend, is that safe???
If the welds hold but the spring hangers bend or break -, is it safe???
If the added weight on the rear that causes some more teetering and tongue flexing causing those welds to crack but the bumper welds hold great, is that safe???

Changing the dynamic loading on a trailer (balancing beam) changes many dynamic loading effects, and IMHO all of them have to be addressed to determine if its safe…

Now if you question is can a welder weld up a substantial bumper that won’t break under static loads the answer is an easy yes, if your luck enough to get away with the loading under dynamic loading, well then you are lucky but not necessarily safe…

As always its your call, but I would recommend you ask the mfg., for the information your looking for…

I had one welded on and it was safe and did a great job. BUT, the rack we used did not have a tray for the wheels to sit on which meant that they hung from the top cross bar and they swung and bounced and really beat the bikes up. Because of the bounce it was difficult to keep the rack attachments tight. They always seemed to loosed up which worried me. When we traded trailers we switched to an over the propane tank rack that we are much happier with. We can see them while towing, they don't bounce and I'll never have another on the back.

It looks like this hitch welds on to the trailer's frame:

http://www.campingworld.com/shopping/item/accessory-adapter/58823


Not sure if there are any bolt-on models out there.

if you are going to get a welder to strengthen the bumper, instead why not fab a front rack? above the propane tanks . same money, moves the weight forward, cleaner, see them in your mirror.
I've fixed too many bumpers.

Rather than go,to the expense and bother of doing that , why not just purchase a receiver that can be bolted on to the frame of the trailer. Probably cheaper, better, and safer.
Barney