i*********5
发帖数: 19210 | | c*********e
发帖数: 69 | 2 Any of those bikes will easily cost more than $10K, I guess, or even $15K.
The tubing looks very aerodynamic. Googled the relationship between bike
speed and wind resistance/drags:
Speed Wind resistance Drivetrain/wheel resistance
========================================================
12 km/h 2.3 N 2.3 N
20 km/h, 5 N 2.4 N
30 km/h 15 N 2.8 N
40 km/h 27 N 4.1 N
50 km/h 44 N 4.5 N
So in the Tour De France the athletes averaging 40km/h needs to resist as
much as twice of wind drags as when we are in the 30km/h range. Astonishing.
【在 i*********5 的大作中提到】
: http://www.bicycling.com/news/2011-tour-de-france/bikes-tour
: http://www.bicycling.com/news/2011-tour-de-france/state-art-bik
| i*********5
发帖数: 19210 | 3 Did you see some of the new TT/tri bikes in the video? They have kind of
square tubing instead of the traditional aero tubes. That's quite
interesting!
【在 c*********e 的大作中提到】
: Any of those bikes will easily cost more than $10K, I guess, or even $15K.
: The tubing looks very aerodynamic. Googled the relationship between bike
: speed and wind resistance/drags:
: Speed Wind resistance Drivetrain/wheel resistance
: ========================================================
: 12 km/h 2.3 N 2.3 N
: 20 km/h, 5 N 2.4 N
: 30 km/h 15 N 2.8 N
: 40 km/h 27 N 4.1 N
: 50 km/h 44 N 4.5 N
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