Yakima has come out with an "RV approved 4 bike rack fitting into a 2" reciever. Here is the link: https://www.yakima.com/roadtrip
Personally, it is a step in the right direction , but I would not buy it as you have to buy several add ons to actually secure the bike. There are no locks, you would (probably) need a stabilizer bar to keep bike(s) from shifting. By the time you add this to a base price of $200, you are approaching $400 real quick. Not really a fan of the Swagman series either, but am thinking real hard about a Thule T2 system, even though it is not "approved" for RV use.m Just a much better system and not much more than a Yakima RoadTrip fully equipped.