Öhlins MTB Spring Rate Calculator
Optimize your TTX22M coil shock performance
Recommended Öhlins Spring Rate
Closest Öhlins spring options based on 23lb/4Nm increments.
How to Choose the Correct Öhlins Coil Spring
Selecting the right spring rate for your Öhlins TTX22M or TTX22M.2 rear shock is critical for achieving the legendary traction and control the brand is known for. Unlike air shocks where you simply adjust a pump, a coil shock requires a physical spring change to match your weight and bike geometry.
The Mathematics of Coil Selection
Our calculator uses the Leverage Ratio (Wheel Travel divided by Shock Stroke) combined with your riding weight to estimate the force required to support the bike at the ideal sag point. For most modern enduro bikes, a sag of 25% to 30% is ideal for the TTX platform.
Understanding Öhlins Spring Increments
Öhlins springs are typically measured in N/mm but are labeled with both N/mm and lb/in. They usually come in increments of 4 N/mm, which translates to roughly 23-25 lbs/in. If the calculator suggests a 432 lbs/in spring, you would generally choose between a 411 lbs/in (72 N/mm) or 434 lbs/in (76 N/mm) depending on whether you prefer a softer or firmer feel.
Key Factors for Your Calculation
- Rider Weight: Always use your "ready-to-ride" weight, including helmet, shoes, protection, and hydration pack.
- Leverage Ratio: This is the relationship between how much the rear wheel moves versus the shock. A ratio of 2.5:1 means for every 2.5mm of wheel travel, the shock compresses 1mm.
- Weight Bias: Most MTBs have a 65% rear weight bias when in a neutral descending position. DH bikes often sit further back (70%), while XC bikes sit more centered.
Example Calculation
If you weigh 180 lbs (82 kg), ride an Enduro bike with 160mm travel and a 65mm stroke shock (Leverage Ratio: 2.46), and desire 28% sag:
The physics requires approximately 117 lbs of force at the rear wheel at the sag point. After accounting for the leverage ratio and stroke, the calculator would recommend a spring rate near 434 lbs/in (76 N/mm).