### Calculating the highest, possible speed you can get

Posted:

**Dec 20 2015 6:19am**I have tried myself on this to figure out the highest real speed I could get with 4kW motor.

P(Motor) = 4kW = 4000W =

A = Stirnfläche des Objekts = face of the object =

CW = Luftwiederstandswert = Air resistance =

D = Dichte der Luft = Density of air = at 400 meters over the sea at 25 degree Celcius =

V = Geschwindigkeit = Speed = That´s what we want to calculate

CR = Rollwiederstandwert = Roll resistance = (downhill wheel with bad conditions) =

m = Masse = Weight of Rider and Bike together = (65kg + 44 kg bike) = around

g = Erdanziehung = gravity =

Verlustfaktor = Dissipation Factor =

4kW = ((0,6/2 x 0,7 x 1,196 x v³)+(41 x 110 x 9,81 x v)) x 1,11

4kW = (0,25116v³)+(44243,1v)) x 1,11

4kW = (0,25116v x 0,25116v x 0,25116v + 44243,1v) x 1,11

4kW = 4510,015938Vv x 1,11___________I /4510,015938

4000 / 4510,015938 = v x 1.11

0,8869148268 = v x 1,11_______________I / 1,11

0,7990223656 = v

Im just not shure if this means 79,9 km/h.

Tell me if you have something to add.

**P(Motor)=((A/2 x CW x D x v³)+(Cr x m x g x v)) x 1,11**P(Motor) = 4kW = 4000W =

**4000**A = Stirnfläche des Objekts = face of the object =

**around 0,6m²**CW = Luftwiederstandswert = Air resistance =

**around 0,7**D = Dichte der Luft = Density of air = at 400 meters over the sea at 25 degree Celcius =

**1,196 kg/m³**V = Geschwindigkeit = Speed = That´s what we want to calculate

CR = Rollwiederstandwert = Roll resistance = (downhill wheel with bad conditions) =

*41 Watts*m = Masse = Weight of Rider and Bike together = (65kg + 44 kg bike) = around

**110 kg.**g = Erdanziehung = gravity =

**9,81**Verlustfaktor = Dissipation Factor =

**at efficiency 89%.***1,11***RED COLORE****= not real, surce on example motorcycle, google search motorcycle.****BlUE COLORE****= personal value or just real data.****GREEN COLORE****= differnt, not consistently data.**

-When calculating it with your datas, you have to change the green marked data, and parts of the blue marked data.-When calculating it with your datas, you have to change the green marked data, and parts of the blue marked data.

4kW = ((0,6/2 x 0,7 x 1,196 x v³)+(41 x 110 x 9,81 x v)) x 1,11

4kW = (0,25116v³)+(44243,1v)) x 1,11

4kW = (0,25116v x 0,25116v x 0,25116v + 44243,1v) x 1,11

4kW = 4510,015938Vv x 1,11___________I /4510,015938

4000 / 4510,015938 = v x 1.11

0,8869148268 = v x 1,11_______________I / 1,11

0,7990223656 = v

=> 79,9 KM/H=> 79,9 KM/H

Im just not shure if this means 79,9 km/h.

Tell me if you have something to add.