ignoring interference and shielding (from the tyre):
Front fender drag coefficient : 2.3
(shape 20)
area: 0,045m x 0,4m = 0,018m2
cda of front fender= 2.3 x 0,018 = 0,0414
which is (via drag to watts calculator at the bottom of the page)
= about 14 watts at 30km/h so less than that :) (because it is behind the tyre)
if only considering the 2 cm it sticks out wider than the tire: about 6 watts at 30km/h for the front fender
Emyr
svenhöek
very rough estimate:
ignoring interference and shielding (from the tyre):
Front fender drag coefficient : 2.3
(shape 20)
area: 0,045m x 0,4m = 0,018m2
cda of front fender= 2.3 x 0,018 = 0,0414
which is (via drag to watts calculator at the bottom of the page)
= about 14 watts at 30km/h so less than that :) (because it is behind the tyre)
if only considering the 2 cm it sticks out wider than the tire: about 6 watts at 30km/h for the front fender
edit:
or apparently buy Bicycle Quarterly Vol. 6, No. 1 and Vol. 6, No. 3. and find out ->
https://janheine.wordpress.com/2012/05/02/aerodynamics-of-real-world-bicycles/
http://djconnel.blogspot.dk/2011/04/aero-road-frame-versus-front-fender.html