Have used this Swagman 4 bike rack for almost 20 years. For our mountain bikes, had to get the top tube adapter from Thule, when we have the straight top tube touring bikes don't need it(the adapter bar). Fits into a standard 2" receiver. We use a security cable with lock to secure bikes so there is no movement on rough roads.
View from the drivers seat
Don't drop bikes too much or you will crunch tire if on rough roads that have protruding rocks,etc.
Dave
2016 F350 Diesel 4X4 CC SRW SB,
2016 Creekside 23RKS, 490W solar, 2000W Xantrex Freedom 2012 inverter, 4 6V GC-2 (450AH)
2006 F350 CC 4X4 sold
2011 Outfitter 9.5' sold
Some Of Our Fun:
http://daveincoldstream.blogspot.ca/