I watched a guy put a bumper pull backhoe trailer on an F150 King Ranch, short bed 4x4. There had to be 2000# tongue weight alone. I would have killed him if he had done this to my truck. The bumper was 6" off the road! Hauled the trailer with a big truck on it 20 miles with no apparent damage! I would say a round bale is no problem on an occasional basis. I wouldn't put one in my Ranger but my F250 no problem!
