This calculator helps you determine the appropriate spring rate for your vehicle's suspension. Understanding spring rate is crucial for achieving optimal handling, ride comfort, and performance. A spring rate is a measure of a spring's stiffness – how much force it takes to compress or extend the spring by a certain distance.
.suspension-spring-rate-calculator {
font-family: Arial, sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 500px;
margin: 20px auto;
background-color: #f9f9f9;
}
.suspension-spring-rate-calculator h2 {
text-align: center;
margin-bottom: 20px;
color: #333;
}
.calculator-inputs {
display: grid;
grid-template-columns: 1fr;
gap: 15px;
margin-bottom: 20px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
.input-group input {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
}
.suspension-spring-rate-calculator button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #4CAF50;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 1.1rem;
transition: background-color 0.3s ease;
}
.suspension-spring-rate-calculator button:hover {
background-color: #45a049;
}
.calculator-result {
margin-top: 20px;
padding: 15px;
background-color: #e0ffe0;
border: 1px solid #b3d9b3;
border-radius: 4px;
text-align: center;
font-size: 1.2rem;
font-weight: bold;
color: #2c6e2e;
}
function calculateSpringRate() {
var unsprungMass = parseFloat(document.getElementById("unsprungMass").value);
var wheelTravel = parseFloat(document.getElementById("wheelTravel").value);
var motionRatio = parseFloat(document.getElementById("motionRatio").value);
var desiredFrequency = parseFloat(document.getElementById("desiredFrequency").value);
var resultElement = document.getElementById("result");
if (isNaN(unsprungMass) || isNaN(wheelTravel) || isNaN(motionRatio) || isNaN(desiredFrequency)) {
resultElement.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (unsprungMass <= 0 || wheelTravel <= 0 || motionRatio <= 0 || desiredFrequency <= 0) {
resultElement.innerHTML = "Please enter positive values for all fields.";
return;
}
// Convert wheel travel from mm to meters
var wheelTravelMeters = wheelTravel / 1000;
// Calculate sprung mass at the wheel
var sprungMassAtWheel = unsprungMass / (motionRatio * motionRatio);
// Calculate spring rate in N/m using the desired frequency formula:
// omega = sqrt(k / m) where omega is angular frequency (2*pi*f)
// k = m * omega^2
// k = m * (2*pi*f)^2
var angularFrequency = 2 * Math.PI * desiredFrequency;
var springRateNm = sprungMassAtWheel * (angularFrequency * angularFrequency);
// Convert spring rate from N/m to lb/in for common automotive use
var springRateLbin = springRateNm * 0.0056999999999999995; // Conversion factor: 1 N/m = 0.0056999999999999995 lb/in
resultElement.innerHTML = "Calculated Spring Rate: " + springRateLbin.toFixed(2) + " lb/in";
}