Some of you may have seen in some of my other posts that we just purchased a new/used 2010 Sandpiper last month. I was really disappointed to find out that the back bumper (weight capacity) was no better than on our light weight Flagstaff 5ver we just got rid of. bahwahhhhh
When all else fails go to the web and search out the manufacturer. Through my research I discovered the manfacturer to be Lippert (they make a lot of stuff for the RV industry). Check out their site Lippert Components, Inc
They have a "store" and sell products and accessories of all types. There I found receiver hitches and bike racks designed to bolt right up (or be welded to) the frame extensions on the Lippert chasis of the Sandpiper.
Eureka!!!!...there's our answer for a proven bike rack and/or receiver. NOTE, their max weight capacities are not all that much, but what the heck, they are designed and approved to hold what many of us need to haul.... a couple of bikes or a couple of Honda 2K generators hanging off the back.
I will warn you that Lippert's store needs a little work as it does not give a lot of technical information about each product. I called in and talked to a couple of folks who were all about helping me get exactly the right product for my application. WOW, I didn't have to press one to speak English and it's made in the USA!!!!