# Calculators and Comparators marius-ciclistu

Torque And RPM Are Clearer Than Power

GEAR RATIO - it is the ratio between the driver shaft angular speed and the driven shaft angular speed. In other words the ratio between the number of teeth of the driven sprocket that is on the driven shaft (rear wheel) and the number of teeth of the driver sprocket that is on the crankset. Example: 0.5:1 which means 0.5 rotations of the crankset at 1 rotation of the wheel. Usually it's symbol is 'i'.

FORCE'S COEFFICIENT - it's the coefficient with which the downforce on the pedals is being multiplied to result the FORCE APPLIED AT THE WHEEL'S CIRCUMFERENCE (without considering the losses from transmission, bearings and tyres).

B - pedal arm lenght (Ex. 165, 170, 172.5, 175, 180 mm).

Z1 - teeth number of crankset's big sprocket.

Z2 - teeth number of crankset's middle sprocket.

Z3 - teeth number of crankset's small sprocket.

z1, z2 ... z12 - teeth number of wheel's sprockets, in ascending order (Ex. z1=14, z2=15...etc. - when the smallest sprocket has 14 teeth).

D - traction wheel's diameter. A table with dimensions can be found here.

Video Tutorial:

## Bike Transmission Calculator and Comparator

Input the pedal arm lenght* (as x.xx).
Example 170.0 mm

B*= mm

Input, from big to small, the crankset sprockets' number of teeth.

Z1*= Z2= Z3=

Input, from small to big, the wheel sprockets' number of teeth.

z1*= z2= z3=
z4= z5= z6=
z7= z8= z9=
z10=z11=z12=

Input wheel's diameter*.

D*= mm

-- Optional data ( show / hide ) --

## Results

Force's coefficient : Gear ratio

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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)

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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)

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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)
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(coef) : (i)

Graph 1

Graph 2