May not be an issue if your roads are smooth but last summer I tried a rear receiver mounted bike rack and it didn't work very well. The rack is so far behind the rear axle of the truck due to the rear overhang of the camper that it acted like a catapult. When driving over rough roads the bikes would try and launch. I did tie them down so they would stay put but they still took a beating. I now just take my wells cargo trailer if the bikes are going and it holds lots of other stuff too.
96' F350 PSD with smoke added, Airbags, Trailmaster SSV shocks, 315/75R16 Toyo M/T, Centering guides.
06' Adventurer 90FWS with leg extensions
06' Jetcraft XS.
94' Wells Cargo 7'x14' Slide-Show
Take a look at the Surco Swing Away Bike Rack from Performanceproducts.com. It swings to the right with the bikes on it, allowing access to the rear camper door. I have an older version that I've used for about 8 years now with no problems.
Haifisch is right on the money. We have carried front and rear, and the bikes do a whole lot better on the front: less debris, less swing, etc. We usually don't drive at night, at least past happy hour, so headlights aren't a problem. Bodiak sells a great front receiver if your truck has tow hooks. Receiver bolts into the tow hooks, and is plenty strong enough for a few bikes. (Google Bodiak for their website) Another good thing about front hauling is that the bikes don't drag on pavement while getting into and out of gas stations, McD's, etc like a lot of rear receivers do as they hang down lower in the rear.
I have been hauling bikes in this fashion for several years. First on Camper Vans now on my Northern Lite. It is fairly simple and inexpensive (less than a $100) and very secure. Once secured there is no movement of the bikes and they are lock in place. The rack is a 60" Yakima bar cut in half with two locking Yakima boa fork clamps. I don't like hanging bikes via the top tube either on a back hitch and for sure not on the front on a vehicle where bike can get spattered with bugs and road grime. I do wipe down the bikes and lube them regularly, especially after long road trip.
I am not worried about the ladder carrier the weight of two 25# bikes. If the ladder can hold my 180# body I believe it should be able carry two bike and bar at less than 60#. The down side is holding the bike in one hand while attaching the fork clamp. The upside is the bikes don't bang against each other and bugs don't get plastered to the bikes. I do stick the bikes inside when the weather get nasty. I also remove the bike seats when traveling. Bike bags are Ok, but the bag tends to buffet in too much so I don't use one. If you need more detail I can shoot a better picture.
2008 Northern Lite 9.6 Queen SE.
Kyocera 85 Watt Solar, Solar Boost 2000E Controller