I had the same problem when I purchased my 2014 312BHX. I emailed Forest River and they game me part numbers.
The bike rack is part number 10f12758a and the mounting brackets are part number 10f12759a. When I talked to a couple of dealers, I discovered it was priced way out of my budget... $384 for the rack, $97 for the mounting kit and $175 for crating and shipping
I ended up ordering just the mounting brackets last week. When I get them, I plan to take some measurements and then see if a local welding shop can make me a rack that works with them.