From Twitter: Troy Rank @grindz145
4177 miles, surpassing the current gwr record for longest motorized bicycle journey! http://instagram.com/p/sQFfONNkwu/
Don't forget about Kingfish's epic trip from Washington to California. He talks a lot about carrying a load including using a trailer:
http://endless-sphere.com/forums/viewtopic.php?f=1&t=28573