3 Stability performance measure of vehicle combinations. 22 . to 16,5 m, but at the same time the length of the semitrailer, i.e. the loading .. The tail swing is. Experiencing trailer sway while towing your RV can be dangerous. Find out what causes A sudden gust, a passing semi truck or a quick steering correction can start your trailer swaying or fishtailing. The loss of Loading too much gear on one side of your camper can unbalance the trailer. Unbalanced.