Many replicas of the bicycle experiment show aerofoils of the size used in the wind tunnel experiments, but according to the diaries they were much larger. The flat surface was 8" by 12 " (approx 18cm by 27cm), and the curved surface was 8" by 18" (approx 18cm by 40cm).
Also the wheel is often shown as being linked to the front wheel and handlebars when it is more likely to have been attached directly to the bicycle frame.
The rider's view. The Lilienthal aerofoil should have balanced the flat plate at an angle of 5 degrees, but instead it had to be at 18 degrees. The Wright Brothers now understood why their gliders had not had the predicted lift.back