Originally Posted by lundah
Our 2014 SP240 has the factory installed cargo/bike rack, and just the rack itself easily weighs over 50 pounds. You can get a bolt-on receiver to fit the 4" bumper (like this one RV Bumper 2" Trailer Hitch Receiver Curt Specialty Trailer Hitches E-100
), so you shouldn't have to void your frame warranty, but keep in mind that adding weight at the rear of the TT is going to effect how it tows so you may need to move other stuff around inside to balance the weight.
I was also going to point out that Surveyor puts on cargo racks as a factory installed option. I was at the Oregon factory and most of the trailers on the line had these racks installed, maybe they're standard now on some models, don't know. I didn't think at the time to look at it in detail or ask about it other than looking at the hinged ladder which is needed to swing out of the way when the rack is tilted up.
Lundah - did your trailer come with any specifications as to the weight carrying limit of the factory installed rack?
Another thing to consider is that putting weight on the rear of the trailer will decrease the tonque weight some (exact amount depends on the length of the trailer and where the axle is), which can cause towing instability/sway etc.