자전거에 프로펠러를 달면?

# 자전거에 프로펠러를 달면? # I dive into my old collection of Popular Mechanics magazines and get inspired to build something! I found Ernest Winter’s air screw bicycle, so I tried to build it. He claims it is able to hit 20 miles per hour, will I be able to match his speed? How will I build the propeller