The Author: Mark Atanowicz | |||||||
Until more precise tests take place it seems that 18 respectively 24 spokes can bear a weight of the cycler up to 85 kg. More spokes on the back wheel are efficient if the cycler has more weight or takes extreme stresses. If one takes a 40 mm rim with 18124 spokes like FIR, Basso and others from the beginning, the more stiff rim profile gives enough security and good aerodynamics. | |||||||
LESS ADVANTAGE: TRI - and FOURSPOKES: not many specimen tested. Delivery Problems ( Specialized Habo ), production stops ( Spin wheel, Mavic Zipp ) and other impediments left only three wheels to be tested. With 6,7 % less need of power Spengle takes the last rank within the complete sets. The single Corima - front wheel, tested with a 36 spokes back wheel is compared to the combination Shamal - front wheel/ 36 spokes back wheel worse, too.. the results show the problems of this type of wheel: carbon wheels are expensive and relatively heavy; the aerodynamics are worse than amongst the spoke wheels. | |||||||
SET OR SINGLE?: The measure results show that the back wheel is very important for the aerodynamics of the combination bike/ cycler. The actual test shows that the Shamal set saves 39 Watt, the front wheel alone with a 36 spokes back wheel only 18 Watt. This suggests that back wheel could save even more energy. BUT: due to possible failures in the measurements and the actual small data - basis a final conclusion could not be made. Only the tendency that both wheels are equally important for the aerodynamics seems to be provable | |||||||
The measurements were made at a constant speed of 45 km/h For the other tables the values were calculated, the roll-resistance and other resistances taken with 4,5 N; chain efficiency: 0.98 | |||||||
All power figures measured in Watt: | |||||||
Test table 1: | 30 km/h |
Test table 2: | 35 km/h |
Test table 3: | 40 km/h |
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Disks: | 352,00 |
Disks: | 352,00 |
Disks: | 352,00 |
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Shamal HPW 12: | 129,10 |
Shamal HPW 12: | 188,89 |
Shamal HPW 12: | 266,35 |
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Cosmic: | 129,69 |
Cosmic: | 189,84 |
Cosmic: | 267,76 |
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Citec 12 Spokes: | 129,99 |
Citec 12 Spokes: | 190,31 |
Citec 12 Spokes: | 268,46 |
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Spinergy: | 130,58 |
Spinergy: | 191,25 |
Spinergy: | 269,86 |
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HED Jet: | 132,36 |
HED Jet: | 194,07 |
HED Jet: | 274,08 |
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Rigida DP 18: | 132,36 |
Rigida DP 18: | 194,07 |
Rigida DP 18: | 274,08 |
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Spengle Tri-Spoke: | 132,66 |
Spengle Tri-Spoke: | 194,54 |
Spengle Tri-Spoke: | 274,78 |
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Shamal FW/36S BW: | 135,32 |
Shamal FW/36S BW: | 198,77 |
Shamal FW/36S BW: | 281,10 |
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Corima VR/ 36S BW: | 136,21 |
Corima VR/ 36S BW: | 200,19 |
Corima VR/ 36S BW: | 283,21 |
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Standard 36 Spokes | 144,66 |
Standard 36 Spokes | 207,24 |
Standard 36 Spokes | 293,74 |
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Power Gain: | 8,3
Watt |
Power Gain: | 13,17
Watt |
Power Gain: | 19,66
Watt |
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Test table 4: | 45 km/h |
Test table 5: | 50 km/h |
Test table 6: | 55 km/h |
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Disks: | 352,00 |
Disks: | 352,00 |
Disks: | 352,00 |
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Shamal HPW 12: | 364,00 |
Shamal HPW 12: | 484,36 |
Shamal HPW 12: | 629,96 |
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Cosmic: | 366,00 |
Cosmic: | 487,10 |
Cosmic: | 633,61 |
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Citec 12 Spokes: | 367,00 |
Citec 12 Spokes: | 488,47 |
Citec 12 Spokes: | 635,43 |
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Spinergy: | 369,00 |
Spinergy: | 491,22 |
Spinergy: | 639,09 |
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HED Jet: | 375,00 |
HED Jet: | 499,45 |
HED Jet: | 650,04 |
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Rigida DP 18: | 375,00 |
Rigida DP 18: | 499,45 |
Rigida DP 18: | 650,04 |
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Spengle Tri-Spoke: | 376,00 |
Spengle Tri-Spoke: | 500,82 |
Spengle Tri-Spoke: | 651,87 |
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Shamal FW/36S BW: | 385,00 |
Shamal FW/36S BW: | 513,17 |
Shamal FW/36S BW: | 668,30 |
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Corima VR/ 36S BW: | 388,00 |
Corima VR/ 36S BW: | 517,17 |
Corima VR/ 36S BW: | 673,77 |
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Standard 36 Spokes: | 403,00 |
Standard 36 Spokes: | 537,86 |
Standard 36 Spokes: | 701,16 |
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Power Gain: | 28 Watt |
Power Gain: | 38, 41 Watt |
Power Gain: | 51,12 Watt |
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