Nun, I was talking with a bicyclist from Iceland who was in the shop recently picking up some road tires and I asked him about cycling the ring road. He mentioned something about people knowing the times when the truck travel is heaviest around the road?

There may be some local conventions as to when the truck travel is heaviest. You might want to ask around about this once you get there.

Have a great time, i've got some UL camping to be done outside of Paris this year if all goes according to plan.