When it comes to hauling heavier electric bikes, most bike racks fall short... not just in their capacity, but in their ability to secure bikes properly to withstand the demands of the road; quick turns, starts, stops and constant vibrations. As Newton's law says, "An object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force."
With heavier bikes, the incremental weight at high moving speeds creates substantial velocity that must be managed tightly at all connection points to keep the bike in synchronized motion with the vehicle. When the car changes directions, the change in directional energy is instantly transferred to the bike, instead of a single part on the rack catching that energy as the bike falls loosely into it with force. This space and looseness is how many electric bikes become loosened or fall off traditional bike racks.
For these reasons, we use tie-downs as an integral part of our electric bike racks. Unlike adjustable bike securing methods on traditional bike racks, tie downs do more; they have unlimited adjustability and put pulling force on the bike greater than the velocity created by the demands of the road, which keeps the bike in perfect tandem with the vehicle and rack.
In our opinion, there is no method superior to using tie downs for heavy hauling.
Safe hauling, friends.