Edit - tables using same values as example below - 180cm/80kg rider, 15kg bike, hands on the tops bike
- narrow racing tyre:
Aproximate power formula P = (0.875492969 * v) + (v3 / 150.37973)
for > 20km/h max error 3.5% / avg error 1.046% (rolling + air)
Share (%)
Speed (km/h) 11 15 20 25
Rolling resistance 49,82 35,42 23,91 16,91%
Air resistance 50,01 64,42 75,94 82,97%
Power needed (W)
Speed (km/h) 11 15 20 25
Rolling resistance 9,63 13,13 17,51 21,89 W
Air resistance 9,67 23,89 55,62 107,43 W
Total power 19,33 37,09 73,23 129,48 W
- robust wide touring tire (%)
Speed (km/h) 11 15 20 25
Rolling resistance 60,15 45,44 32,30 23,59%
Air resistance 39,85 54,56 67,70 76,41%
Speed (km/h) 11 15 20 25
Rolling resistance 14,59 19,90 26,53 33,17 W
Air resistance 9,67 23,89 55,62 107,43 W
Total power 24,26 43,79 82,15 140,60 W
In
Michael's link rolling resistance formula is computed this way:
CrEff = LoadV[Bike#] * CCrV[Bike#] * CrV + (1.0 - LoadV[Bike#]) * CrH
(Rolling drag coefficients:
Cr front (w/o wheeldiameter correction): CrV
Cr rear: CrH)
Frg = 9.81 * weight * (CrEff * cos(Slope) + sin(Slope))
P = Cm[bike#] * V * (... + Frg)
Power loss of tyres, flat:
P = Cm[bike#] * V * 9.81 * weight * CrEff
Example 80kg rider, 15kg bike, narrow racing tyre (Cm = 1,025 - hands on the tops):
P = v * 0,8756446875 (W; km/h)
(24,32% of 72W share @20km/h)
or
P = v * 1,326734375 for robust wide touring tires (thread)
(29,48% of 90W share @20km/h)
Power ratio between narrow and worst resistance tyres in example from that form is 25% (72/90W).
Tyre description Cr
narrow racing tire (high pressure) 0.0033
medium-wide high pressure slick 0.0031
wide high pressure slick 0.0029
robust wide touring tire (thread) 0.0050
Rinkowsky radial ply tire (wide slick) 0.0016
offroad tire 1.75" 0.0046
Bike# + description LoadV CCrV
0 Roadster 0.33 1
1 MTB 0.45 1
2 Tandem 0.5 1
3 hands on the tops (top of handlebar) 0.4 1
4 hands on the drops (bottom of handlebar) 0.45 1
5 Triathlon Bicycle 0.47 1
6 Superman Position 0.48 1
7 Tandem with racing bars 0.32 1.25
8 LongWheelBase under seat steering, commuting equipped 0.55 1.25
9 ShortWheelBase under seat steering, commuting equipped 0.55 1.25
10 Lowracer above seat steering Kreuzotter race 0.63 1.25
11 Streamlining tailbox Kreuzotter race 0.63 1.25
12 Streamlined Lowracer White Hawk 0.55 1.25
13 Streamlined Trike Quest 0.72 1.5
14 Handbike 3 wheel 0.5 1.5
Do not like public lies - here is one example:
LaFerrari (400km/h top speed) could be overtaken by Peel P50 (45km/h), but do not take it seriously - one went out of petrol or was parking probably ;-)
Anyway one can pay 3x more for top wider to beat worst narrow (by resistance) if he feel physics or material limits are misleading.