Aero Wheel info

24" Wheel Weight (g)Rotating Drag(g)
Trialist Flat Carbon Disk 950 97
Accel Kevlar Lens Disk 480 100
Vortex 12 Spoke Prototype 790 109
Hooker 18 Aero Spoke, Aero Rim 490 136
Elite 18 Aero Spoke, Aero Rim 500 154
26" Wheel Weight (g)Rotating Drag (g)
26" Accel Kevlar Lens Disk 590 95
Trialist Flat Carbon Disk 900 101
26" HED CX 18 Aero Spoke 850 139
Elite 18 Aero Spoke, Aero Rim 530 145
27" Composite Spoke Wheel Weight (g)Rotating Drag (g)
Aerosports 3-spoke Prototype 720 106
Trispoke (3-spoke) 720 112
Specialized (3-spoke) 1330 114
Zipp (3-spoke) 850 129
Corima (4-spoke) 1590 131
FIR Halley (3-spoke) 1530 142
27" Disk Wheel Weight (g)Rotating Drag (g)
Gipiemme Lens Disk 1107 101
Trialist Flat Carbon Disk 1035 105
Carbotec Lens Disk 1135 108
Spengle Lens Clincher Disk 1480 109
Zipp 950 Carbon Flat Disk 950 112
HED Flat Carbon Disk 1050 114
Accel Kevlar Lens Disk 710 118
Radsport Lens Disk 1900 123
27" Steel Spoke Wheel Weight (g)Rotating Drag (g)
Roval 18 Aero Spoke, Aero Rim 680 149
Elite 18 Aero Spoke, Aero Rim 580 162
source: UC Irvine Wind Tunnel Tests / Jan-1991 (Cycling Science, March-91)
taken from ftp://ftp.netcom.com/pub/ba/banders
Below are representative results for Cx. They are nearly independent of airspeed (10, 20, 30 mph were used).
Technical details of the study
Observations
Wind Angle: 0.0 7.5 15.0 22.5 30.0 37.5 45.0 55.0 65.0
36-spoke 0.047 0.057 0.061 0.059 0.058 0.070 0.057 0.045 0.029
Campy Shamal 0.037 0.047 0.043 0.045 0.036 0.028 0.018 0.010 0.000
HED CX 0.035 0.028 0.034 0.041 0.042 0.039 0.030 0.019 0.011
Specialized 0.036 0.038 0.028 0.031 0.028 0.020 0.009 0.006 -.001
FIR 0.036 0.026 0.034 0.041 0.037 0.032 0.020 0.011 0.002
HED disk 0.036 0.020 -.004 -.005 0.000 0.001 -.003 -.005
ZIPP 950 0.036 0.023 0.013 0.017 0.018 0.017 0.016 0.016
The above are taken from the middle of a crayon line drawn through very numerous data points. Typical scatter is +/- 0.002 to 0.005. For comparison, Cx = 0.8 for the whole bike/rider combo. (based on a typical crouched-racer 0.3 m^2 drag area quoted in Whitt and Wilson).
apparent (?) source: UC Irvine Wind Tunnel Tests / Jan-1991 (Cycling Science, March-91)
taken from ftp://ftp.netcom.com/pub/ba/banders
WheelDrag at relative angle
Spokes057.51010
FiberFlight/Op4-Ult32.51.52.53.56.58
GP4-Ultegra32.50.47.49.49.54
HED J2 Sonic24.30.31.34.37.35
HED Jet Sonic24.32.29.27.27.21
HED CX Sonic12.31.29.26.20.20
HED Deep Sonic12.28.29.25.18.10
HED Disk0.25.23.17.12.01
source: HED supplied