Chain Drive Tension Calculator - Calculator Academy

Reviewed By: Patrick Myers (BSME)

Enter the applied force magnitude and the angle between the force direction and the chain direction into the Chain Drive Tension Calculator. The calculator will evaluate the component of force along the chain (i.e., the tension component in the chain direction, under this simplified force-resolution model).

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Chain Drive Tension Formula

The following example problem outlines the steps and information needed to calculate the component of an applied force along the chain direction (the “tension component” used in this simplified force-resolution model).

CDT = AF \cdot \cos(CDA)

Variables:

CDT is the tension component along the chain direction (N)
AF is the applied force magnitude (N)
CDA is the angle between the applied force direction and the chain direction (degrees or radians)

To calculate the along-chain tension component, multiply the applied force magnitude by the cosine of the angle between the force direction and the chain direction. Note: power-transmitting chain drives are often analyzed using tight-side and slack-side tensions derived from torque/power and sprocket radius; this calculator is for resolving a force into its along-chain component.

How to Calculate Chain Drive Tension?

The following steps outline how to calculate the tension component along the chain direction.

First, determine the applied force magnitude (N).
Next, determine the angle between the applied force direction and the chain direction (degrees or radians).
Next, gather the formula from above: CDT = AF * COS (CDA).
Finally, calculate the along-chain tension component (CDT).
After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem :

Use the following variables as an example problem to test your knowledge.

applied force magnitude (N) = 30

angle between force and chain direction (degrees) = 45

CDT = AF * COS (CDA) = 30 × cos(45°) = 21.2132 N

Follow-Up Calculations

If this calculator gives you about 240 lbf of chain tension on a 12-tooth driver turning a 36-tooth driven sprocket, that 3:1 reduction means 3,000 engine rpm becomes about 1,000 rpm at the output shaft. You can work out the sprocket speed to confirm the driven rpm before you judge whether the chain is large enough for the torque you’re sending through it.

A 240 lbf tight-side chain tension on a jackshaft sprocket puts roughly the same sideways force into the shaft and bearing set, especially when the chain wraps only partway around the sprocket. Use the shaft load from the chain calculation to see whether your bearings can handle that side force, because bearing life drops quickly as radial load rises.

If your chain tension calculation says the drive can handle 240 lbf and you are running a 3:1 reduction, a 26-inch tire will make the vehicle travel about 77 mph at 1,000 wheel rpm. You can turn that into road speed to compare drivetrain durability with the actual speed you want, which is often the real design target.