300 pound Dual Sport went off hitch carrier on Chevy @ 60 mph: 4 Ancra Tie downs were on snug and stayed hooked to bike, front tire dragged on highway making a long skid mark after a loud low boom. Bike OK, front tire had extra wear on one edge. It spun while dragging. Bike scratched rear door of Suburban. Why? Fast right hand sweeper wanted bike to go forward as did the main ratchet clamps from 2 receiver up to frame just above and to the rear. The front pair of cam lock clamps dont do much but tend to twist the channel as bike rocks, it was raining, forgot to put bike in gear, didnt wrap either tire down to channel, main channel twisted, metal ramp against front tire cocked and front tire suddenly rolled forward by ramp, and shot out and down to road. "Cycle Country" brand carrier has a short ramp without sides. Now: Cam lock front to whimpy cross bar first as before to make bike hands free, ratchets on each side to receiver from frame as before. Add simple straps holding front tire (inboard of cross bar) and rear tire down to channel. A year ago, had a different "close call." Used a single center ratchet strap, up one side, across and down the other with an extra wrap or two before crossing. Well that wrap slipped and bike tipped about 30 degrees but was still "tight." Now I use a separate ratchet strap for each side.