SOME COMMENTS on EQU lPMENT - Home - Presque Isle...
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Part III: Part III: SOME COMMENTS on SOME COMMENTS on EQU EQU l l PMENT PMENT
Transcript of SOME COMMENTS on EQU lPMENT - Home - Presque Isle...
Part III:Part III:
SOME COMMENTS on SOME COMMENTS on EQUEQUllPMENTPMENT
Recommended TT bike frames (2004)Recommended TT bike frames (2004)
�� Lotus*Lotus*
�� HottaHotta**
�� ZIPP*ZIPP*
�� Hooker*Hooker*
�� CervCervéélolo P3P3
�� TiemeyerTiemeyer (custom)(custom)
�� GT*GT*
�� TrekTrek
�� JavelinJavelin
*out*out--ofof--productionproduction
monocoquemonocoque
doubledouble--diamonddiamond
Recommended TT bike frames Recommended TT bike frames (updated)(updated)
When this presentation was first prepared in 2004, the only carbWhen this presentation was first prepared in 2004, the only carbon on fiber TT frames on the market were the fiber TT frames on the market were the CervCervéélolo P3C, Trek TTX, and P3C, Trek TTX, and Bicycle Technologies. Numerous others have appeared in since. Bicycle Technologies. Numerous others have appeared in since.
Carbon fiber has the Carbon fiber has the potentialpotential to reduce the drag coefficient of to reduce the drag coefficient of frames and components since it is moldable to most any shape andframes and components since it is moldable to most any shape andproduces a more integrated, produces a more integrated, ‘‘cleanercleaner’’ form with fewer edges. Still, form with fewer edges. Still, just because it just because it cancan be molded to an optimal shape, doesnbe molded to an optimal shape, doesn’’t mean it t mean it isis; if not, any benefit of carbon fiber construction can be ; if not, any benefit of carbon fiber construction can be significantly compromised.significantly compromised.
Each company claims to have done extensive windEach company claims to have done extensive wind--tunnel testing, tunnel testing, and the new models do indeed appear to be more aerodynamically and the new models do indeed appear to be more aerodynamically efficient, but manufacturer data is proprietary, and no independefficient, but manufacturer data is proprietary, and no independent ent testing has been conducted. testing has been conducted.
Bicycle Technologies
BMC
BMC
Cervélo P3C
Cervélo P4C
Felt DA
Felt DA
Fuji
Giant
Scott Plasma
Scott Plasma
Specialized S-Works
Specialized S-Works
Trek TTX
What makes a wheel What makes a wheel
‘‘wheelywheely fastfast’’ ? ? ☺☺☺☺☺☺☺☺
From From KraigKraig WilletWillet’’s wheel test article at s wheel test article at
bike.combike.com, the relative importance of wheel , the relative importance of wheel
design parameters is as follows:design parameters is as follows:
1.1. rim depth/shape (~80%) rim depth/shape (~80%)
2.2. spoke count (~10%) spoke count (~10%)
3.3. hub shape (~8%) hub shape (~8%)
4.4. spoke shape/diameter (~2%) spoke shape/diameter (~2%)
Oran W. Nicks low-speed wind tunnel at Texas A & M University, College Station, TX
MODEL
Spoke count,shape,
lacing pattern
Rim Depth(mm)
conical, smooth surface
18, oval, radial
3, bladed, radial
16, bladed, radial
flat, smooth surface
20, bladed, radial
20, oval, radial
32, 2.0/1.8 DB, 3X
SPECIFICATIONS
(disc)
58 mm
55 mm
52 mm
(disc)
23 mm
30 mm
19 mm
All information copyrighted 2003 by K-dub Enterprises.
All are front wheels except for the disk and wheel cover. The same Continental Ultra Sport 700C x 20 mm Kevlar beaded clincher tire was used on all models except the disk, where a Performance 20mm tubular tire was used.
0.2540.0490.1900.2910.3390.400CH Aero wheel cover
0.3070.2520.1810.2810.3800.441Zipp 404
0.3200.2600.2410.2790.4310.387Specialized Tri-spoke
0.3460.3480.3480.2620.3900.384Mavic Cosmic Carbone
0.3500.3000.2810.3380.4320.400Zipp 950
0.4430.4520.4190.4520.4710.419Bontrager Race Lite
0.4600.4130.4000.4130.5230.552FIR SRG 30
0.6070.5730.5430.5910.6550.675Ritchey
MEAN20°15°10°5°0°
Yaw Angle
DRAG (lbs.) at 30 MPH
AERODYNAMIC DRAG of SELECTED BICYCLE WHEELSTexas A & M Low Speed Wind Tunnel Test Session, 13 January 2003
Rules of thumb for Rules of thumb for
reductions in air dragreductions in air drag
At 30 mph, a reduction At 30 mph, a reduction of 0.005 mof 0.005 m22 in in CCDDAA
= ~ = ~ --0.5 seconds/km 0.5 seconds/km
= ~ = ~ --0.1 lbs drag0.1 lbs drag
= ~ +7 W= ~ +7 W
At 25 mph, a reduction At 25 mph, a reduction of 0.005 mof 0.005 m22 in in CCDDAA
= ~ = ~ --0.5 seconds/km 0.5 seconds/km
= ~ = ~ --0.1 lbs drag0.1 lbs drag
= ~ +4 W= ~ +4 W
Drag of selected bicycle wheels at 30 mphDrag of selected bicycle wheels at 30 mph
Scale comparison of selected aerodynamic rimsScale comparison of selected aerodynamic rims
HED 90(90 mm)
Zipp 808(82 mm)
Zipp 404(58 mm)
HED Alps,
HED H3(55 mm)
Mavic
Cosmic Carbone(52 mm)
ReynoldsStratus
(46 mm)
Bontrager Race X-lite Carbon
(44 mm)
Zipp 303,CampagnoloShamal
(38 mm)
VelocityDeep V(30 mm)
OthersOthers
Campagnolo Bora (50 mm) 18/21
Campagnolo Eurus, Zonda (30 mm) 16/21; Scirocco (30 mm), 24/24
FSA K Force (38 mm) 12/18
90 mm
82 mm
Tire/rim interface
0.3960.3380.3490.3580.4480.489Specialized Tri-spoke (25 mm tire)
0.3200.2600.2410.2790.4310.387Specialized Tri-spoke (20 mm tire)
MODEL
DRAG (lbs.) at 30 MPH
All information copyrighted 2003 by K-dub Enterprises.
All are front wheels.
0.4020.4310.3410.3410.4200.479Zipp 404 (25 mm tire)
0.3070.2520.1810.2810.3800.441Zipp 404 (20 mm tire)
0.6070.5730.5430.5910.6550.675Ritchey
MEAN20°15°10°5°0°
Yaw Angle
EFFECT of TIRE WIDTH on BICYCLE WHEEL DRAGTexas A & M Low Speed Wind Tunnel Test Session, 13 January 2003
Effect of tire width on bicycle wheel dragEffect of tire width on bicycle wheel drag
0.2950.2330.1800.2840.3770.404lenticular shape(disc)Disc
MODEL
Spoke count,shape,
lacing pattern
Rim Depth(mm)
3, bladed, radial
28/28, bladed, 2X
24/16, bladed, 2X/radial
28/24, bladed, 2X
28/24, bladed, 2X
32, DB, 3X
SPECIFICATIONS
55 mm
90 mm
55 mm
60 mm
40 mm
n/a
Data retrieved from HED web site (archived).
0.3430.2780.3130.3210.3970.409H3
0.3620.3930.2750.3120.3940.438Jet 90
0.3830.4150.4000.3040.3920.406Alps
0.4330.4850.4060.4270.4180.430Jet 60
0.4580.5590.4680.4370.4180.408Jet 40
0.6490.8380.6410.6280.6040.534Box section rim
MEAN20°15°10°5°0°
Yaw Angle
DRAG (lbs.) at 30 MPH
AERODYNAMIC DRAG of HED BICYCLE WHEELS
MODEL
Data retrieved from the Bicycle Sports web site.
0.1450.0810.0860.1980.216HED Deep/S90
0.1680.1090.1170.2230.223HED 3 (tri-spoke)
0.1910.1250.1420.2430.255ZIPP 404
0.2550.2070.2510.2840.279LEW
0.2670.2670.2540.2960.252HED Jet
0.3000.3200.3360.2850.259HED J-2
0.3140.3730.3140.3060.261Shimano WC-7700 w/ 23 mm tire
0.3760.3580.4020.4250.318Rolf Vector
0.4060.4140.4020.4080.401Std. box rim, 32 spokes
0.4100.4140.4450.3800.399Mavic Helium
0.5470.5960.6520.4940.445Spinergy Spox
MEAN15°10°5°0°
Yaw Angle
DRAG (lbs.) at 25 (?) MPH
AERODYNAMIC DRAG of SELECTED BICYCLE WHEELSTexas A & M Low Speed Wind Tunnel Test Session, January 2000
MEAN0-20°0-10°
0.67
0.67
0.71
0.83
0.61
0.62
0.67
0.78
0.70
0.71
0.73
0.87
DRAG at 30 mph(lbs.)
1.94
1.66
1.31
0.91
front/side
MODEL
sidefront
0.0182
0.0184
0.0169
0.0123
AREA(m2)
0.0094
0.0111
0.0129
0.0135
All information copyrighted 2003 by K-dub Enterprises, www.biketechreview.com.
All forks were tested with an 18 spoke Zipp 404 clincher wheel and 700x20c tire inflated to 110 psi. The wheel was spun at the same speed as the air moving past it.
30.54.003.603.10Reynolds Ouzo Pro Aero
35.03.053.053.02Oval Jetstream
38.02.602.602.90True Temper Alpha Q
30.81.201.602.001996 Kestrel EMS
BLADE SEPARATIONat CROWN(mm)dropoutmidspancrown
LENGTH/DEPTH RATIO
AERODYNAMIC DRAG of SELECTED BICYCLE FORKS Texas A & M Low Speed Wind Tunnel Test Session, 13 January 2003
Time±24.5 s
Power±2 W
24
34
34
Gain over 40 kmat 20 mph
Model
Time± 4 s
Power±3 W
20
26
26
Gain over 40 kmat 30 mph
8
10
10
All information copyrighted 2003 by K-dub Enterprises, www.biketechreview.com.
Time and power savings are in relation to a Kestrel EMS fork.
2244True Temper Alpha Q
3306Oval Jetstream
3336Reynolds Ouzo Pro Aero
Time±12.5 s
Power±2.5 W
Gain over 40 kmat 25 mph
BENEFIT of SELECTED AERODYNAMIC BICYCLE FORKS
Texas A & M Low Speed Wind Tunnel Test Session, 13 January 2003
Time saved from reduction in effective frontal area.
Relative time saved by mass reduction.
Relative distance saved by mass reduction.
biketechreview.com
Aero bars and more equipment tested at
