We’ve slowly learned something about wind resistance and electric cars. More wind resistance cuts mile range a lot. A trailer hitch bike rack behind the car is like an abstract art installation parachute. Bikes don’t go sideways. But, in the meant-to-be smooth airflow behind a Tesla, sideways bikes create suction. On our trip from Seattle to Oakland, we were alarmed by our battery consumption: 100 actual road miles were costing us 200 e-miles. We had cool temperature, hills and wind drag against us. We had to solve this for the return trip.
We removed the seat posts with seats. These stuck up the highest of any part of the bikes. We removed the front wheels and supported the front of the bikes by the inside top of the forks. This eliminated the side drag of one wheel; reduced the amount the bike stuck out behind each side of the car; and turned the handlebars to face the wind head on. We used 175 e-miles to go 160 road miles, granted under different circumstances: temperature between 60 and 65 degrees and slightly more downhill miles than uphill miles. I am sure the reduced drag made a difference: the low frequency hum from behind the car was much quieter.