Enter the mass of the weight (kg) and the difference in fork length (mm) into the Fork Spring Rate Calculator. The calculator will evaluate the Fork Spring Rate. 

Fork Spring Rate Formula

The following two example problems outline the steps and information needed to calculate the Fork Spring Rate.

FSR = M / L

  • Where FSR is the Fork Spring Rate (kg/mm)
  • M is the mass of the weight (kg) 
  • L is the difference in fork length (mm) 

How to Calculate Fork Spring Rate?

The following example problems outline how to calculate Fork Spring Rate.

Example Problem #1:

  1. First, determine the mass of the weight (kg). 
    • The mass of the weight (kg) is given as: 30.
  2. Next, determine the difference in fork length (mm). 
    • The difference in fork length (mm) is provided as: 5.
  3. Finally, calculate the Fork Spring Rate using the equation above: 

FSR = M / L

The values provided above are inserted into the equation below and computed.

FSR = 30 / 5 = 6.00 (kg/mm)


Example Problem #2: 

For this problem, the variables required are provided below:

mass of the weight (kg) = 40

difference in fork length (mm) = 3

Test your knowledge using the equation and check your answer with the calculator..

FSR = M / L = ?