Ohlins Shock Calculator

Optimize your motorcycle’s suspension with our precision ohlins shock calculator. Find your ideal spring rate and sag for ultimate performance and control.

Riding Style	Recommended Rear Rider Sag	Typical Static Sag
Street / Sport	25-35 mm	5-10 mm
Track / Race	20-30 mm	3-8 mm
Off-road / Motocross	95-110 mm	25-35 mm

General sag recommendations. Use this ohlins shock calculator for a more personalized result.

What is an Ohlins Shock Calculator?

An Ohlins Shock Calculator is a specialized tool designed to help motorcycle riders determine the optimal suspension settings, specifically focusing on spring rate and sag. Unlike a generic calculator, an ohlins shock calculator uses inputs critical to suspension dynamics—such as rider weight and riding style—to provide tailored recommendations. The goal is to optimize the bike’s handling, traction, and comfort by ensuring the suspension operates within its ideal range. Proper setup is a cornerstone of performance, and using an ohlins shock calculator is the first step towards a perfectly balanced machine.

This tool is essential for serious riders, from track day enthusiasts to dedicated street riders and off-road adventurers. Misconceptions often arise that stock settings are sufficient, but a stock setup is a compromise designed for an “average” rider that may not exist. An ohlins shock calculator removes the guesswork, providing a scientific baseline for further fine-tuning of compression and rebound damping.

Ohlins Shock Calculator: Formula and Mathematical Explanation

The core of any ohlins shock calculator revolves around two key metrics: Sag and Suggested Spring Rate. While the precise spring rate formula can be complex, involving leverage ratios, we use a proven estimation model combined with empirical data for reliability.

1. Sag Calculation: Sag is the amount the suspension compresses under weight.

• Static Sag = L1 (Unladen Length) – L2 (Static Length)
• Rider Sag = L1 (Unladen Length) – L3 (Rider-On Length)

Getting these values right is the foundation of motorcycle suspension setup. Our ohlins shock calculator makes this process straightforward.

2. Suggested Spring Rate Estimation: A simplified but effective formula is:

Suggested Spring Rate ≈ (Rider Weight × Riding Style Multiplier) × Base Factor

This formula provides a strong starting point. The Riding Style Multiplier adjusts the stiffness: higher for aggressive track riding (more force) and lower for plush off-road absorption.

Variables Table

Variable	Meaning	Unit	Typical Range
Rider Weight	Rider’s mass with all gear	kg	50 – 130
L1, L2, L3	Suspension length measurements	mm	250 – 500
Spring Rate	Stiffness of the shock spring	N/mm	80 – 120
Rider Sag	Suspension compression with rider	mm	25 – 40 (Street/Track)

Practical Examples (Real-World Use Cases)

Example 1: Track Day Enthusiast

A rider weighing 90kg (with gear) prepares their bike for a track day. They use the ohlins shock calculator with the “Track / Race” setting.

• Inputs: Weight = 90kg, Style = Track, L1 = 300mm, L2 = 295mm, L3 = 270mm.
• Calculator Outputs: Suggested Spring Rate = 108 N/mm, Rider Sag = 30mm, Static Sag = 5mm.
• Interpretation: The 30mm rider sag is perfect for track use, providing a firm, responsive chassis. The spring rate of 108 N/mm is appropriate for the high forces experienced during aggressive braking and cornering. This data from the ohlins shock calculator confirms the bike is ready for the circuit. For more details on setup, see our guide on motorcycle suspension setup.

Example 2: Street Rider

A 75kg rider uses their motorcycle primarily for street and canyon riding. They seek a balance of comfort and performance.

• Inputs: Weight = 75kg, Style = Street/Sport, L1 = 315mm, L2 = 310mm, L3 = 280mm.
• Calculator Outputs: Suggested Spring Rate = 90 N/mm, Rider Sag = 35mm, Static Sag = 5mm.
• Interpretation: The 35mm rider sag offers a compliant ride for imperfect street surfaces while maintaining good handling. The 90 N/mm spring is ideal for this weight, ensuring the suspension isn’t overly harsh. Using an ohlins shock calculator has helped this rider achieve a much better setup than the factory default. Checking an ohlins spring rate chart can provide further validation.

How to Use This Ohlins Shock Calculator

Follow these steps for an accurate reading:

1. Enter Rider Weight: Put on all your gear (helmet, leathers, boots) and weigh yourself. Enter this value in kilograms.
2. Select Riding Style: Choose the option that best reflects your primary use. This adjusts the ohlins shock calculator’s internal multipliers.
3. Measure Suspension Lengths: This requires a friend’s help.
   • L1: Place the bike on a stand so the rear wheel is off the ground. Measure from the axle to a fixed point on the tail.
   • L2: Take the bike off the stand. Let it rest under its own weight. Measure between the same two points.
   • L3: Sit on the bike in your normal riding position with feet on the pegs. Have a friend balance the bike and take the final measurement.
4. Read the Results: The ohlins shock calculator instantly provides your suggested spring rate and sag values. Compare your sag to the target ranges in the table. If your rider sag is too high, you need to add more preload; if too low, reduce preload. If you can’t achieve correct sag with preload adjustments, you need a different spring, as suggested by the calculator.

Key Factors That Affect Ohlins Shock Calculator Results

The accuracy of an ohlins shock calculator depends on several critical factors. Understanding them will improve your setup.

• Rider Weight: The single most important factor. A 5kg change can significantly alter the required spring rate.
• Riding Style: A track rider needs a stiffer setup to handle high loads, while a touring rider prioritizes comfort. Our ohlins shock calculator accounts for this.
• Motorcycle Geometry: The linkage ratio of the rear suspension multiplies the force on the shock. While our calculator uses an effective average, custom builds might need a leverage ratio analyzer.
• Tire Choice and Pressure: Tires are part of the suspension system. Different tire profiles and pressures can subtly change ride height and affect sag measurements.
• Component Stiction: Friction in the shock seals or linkage bearings can prevent the suspension from moving freely, leading to inaccurate sag readings. Regular maintenance is key. Learn more about how to set shock sag correctly.
• Load Variation: If you frequently ride with a passenger or luggage, you must perform calculations for that load as well. You may need a compromise setting or a spring with a more progressive rate.

Frequently Asked Questions (FAQ)

1. How accurate is an online ohlins shock calculator?

Our ohlins shock calculator provides a highly accurate baseline setting. It’s designed to get you 90% of the way there. Final adjustments should always be made based on feel and specific track or road conditions.

2. What if my sag is correct but the ride feels harsh?

This usually points to damping settings. Your spring rate is likely correct, but your compression damping may be too high. Try reducing it by a few clicks. This is a common tuning issue beyond a basic ohlins shock calculator.

3. Can I use this ohlins shock calculator for any brand of shock?

Yes. The principles of sag and spring rate are universal. While this is titled as an ohlins shock calculator, the physics applies to all quality motorcycle suspension, including Showa, WP, and others.

4. How often should I check my sag?

Check your sag at the beginning of every season and after any significant change (new tires, major service, or a change in your weight). Regular checks ensure consistent performance.

5. My static sag is zero or negative. What does that mean?

This typically means the spring is too soft for your weight. The bike is already using up a significant portion of its travel just sitting there, and adding your weight overwhelms it. The ohlins shock calculator will recommend a stiffer spring.

6. Why is there a separate setting for “Track”?

Track riding involves much higher speeds and forces. A stiffer setup is needed to maintain chassis stability during hard braking, acceleration, and cornering. Our ohlins shock calculator adjusts the spring rate suggestion accordingly.

7. What is “stiction” and how does it affect my readings?

Stiction is static friction that needs to be overcome to get the suspension moving. Dirty seals or worn linkage bearings are common causes. It can make sag readings inconsistent. That’s why it’s good practice to push down on the suspension and let it settle before measuring.

8. Is a higher spring rate always better for performance?

No. The “best” spring rate is the one that is correct for your weight and application. A spring that is too stiff will not compress enough, leading to a harsh ride and loss of traction. The goal of an ohlins shock calculator is to find the *correct* rate, not the highest one.