I asked about bogey wheels and 3 different people said don't bother they hang to low and won't help out on my gravel driveway. They all suggested getting a piece of heavy wall pipe, cutting it in half, and welding it in areas that are issues. Mine being across the rear of my trailer because I back it down the hill and it levels off at the bottom.
Now 4 people. They hang too low and get torn off. The rolling pipe is the way to go and can be tucked up tight.
Got a picture of this set up?
I don't, sorry. Trailer is up against the fence! I just used a scrap piece of pipe with another slid inside. The inside piece has brackets on each end, that captures the larger piece, and attaches to the frame. If it bottoms, the long pipe distributes the load down the length into the frame and rolls to reduce friction against the asphalt or concrete.
