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MTB-Raceshop PRO Suspension · Setup Tool

Calculate the MTB spring rate for coil shocks

From a quick starting value to a millimetre-accurate leverage curve – transparent, traceable and matched to your bike. With 29 bike presets, ratio curves and results in lb/in and N/mm.

To the calculator Coil springs in the shop
01 · BERECHNUNGSWEG

Wie möchtest du starten?

Wähle zuerst den passenden Einstieg. Du kannst später jederzeit genauer werden.
02 · DEINE ANGABEN

Basis für die Berechnung

Prozent des Dämpferhubs. Optional leer lassen, um das Preset zu verwenden.
Die Lastverteilung kann über zwei Waagen gemessen oder aus Radstand, Rear Center und Fahrerposition geschätzt werden. Waagenwerte haben Vorrang vor der Geometrieschätzung.
Expertenmodus aktiv: Die Punktkurve ersetzt für diese Berechnung die durchschnittliche Ratio des Bike-Presets. Bike, Variante, Federweg und Dämpferhub bleiben die Referenz.
Trage für jede Dämpferposition die Leverage Ratio als Hinterradweg ÷ Dämpferhub ein. Die Kurve wird integriert und ist im Expertenmodus die maßgebliche Grundlage der Berechnung.
Format: Dämpferposition;Ratio – eine Zeile pro Tabellenpunkt. Alternativ nur eine Ratio pro Zeile. Nach der Übernahme ist die Tabelle maßgeblich.
Dämpferhub eingeben und anschließend eine Kurve erzeugen oder übernehmen.
Gilt nur ohne Expertenmodus. Leer lassen für Federweg ÷ Dämpferhub. Der Durchschnitt bildet progressive Hinterbauten nur näherungsweise ab.

Lastverteilung messen

Bike + Fahrer inklusive Gear in der SAG-Fahrposition wiegen. Beide Räder müssen auf gleicher Höhe stehen.

Lastverteilung aus Geometrie

Wird automatisch aus dem Bike-Preset übernommen oder kann im Standardmodus manuell eingetragen werden. Der effektive Fahrer-Offset ist mit Herstellerwerten kalibriert.
Horizontal vor dem Tretlager; 130 mm ist der kalibrierte Gravity-Startwert.

Coil-Vorspannung

Nur verwenden, wenn die axiale Vorspannung bekannt ist. Umdrehungen sind je nach Dämpfer nicht automatisch Millimeter.

Methodology · explained transparently

What really goes into the result

With the MTB-Raceshop PRO Suspension spring rate calculator, you find a technically sound starting value for the coil spring of your mountain bike. The tool takes into account rider weight including kit, bike weight, desired shock SAG, rear wheel travel, shock stroke and the rear suspension kinematics. For selected bikes, size-specific geometry improves the load distribution; measured front and rear wheel loads take priority.

For quick orientation, there is a quick check and current enduro and downhill bike presets. If leverage ratio data per millimetre of shock stroke is available, expert mode also maps progressive or regressive rear suspension kinematics more accurately. The result is given in lb/in and N/mm and remains a starting value for the subsequent SAG and real-world test.

  • Leverage ratio

    The average ratio is rear wheel travel ÷ shock stroke. It's quick and usable, but only approximates progressive rear ends.

  • Bike preset

    The preset takes over the manufacturer's dimensions, shock SAG and – where available – the geometry of the selected frame size for better load distribution.

  • Ratio curve

    In expert mode, one value per millimetre of shock stroke describes where the rear wheel is in its travel. This refines the calculation for non-linear kinematics.

  • Load distribution

    The calculator estimates the rear wheel load from wheelbase, rear centre and a calibrated rider position. Measured front and rear wheel loads always take priority.

Frequently asked questions about coil spring rates

What details does the MTB spring rate calculator need?

Rider weight including kit, bike weight, rear wheel travel, shock stroke and desired shock SAG are enough for a solid starting value. Bike size, geometry or two scales improve the load distribution.

What does leverage ratio mean on a mountain bike?

The leverage ratio describes the relationship between rear wheel travel and shock stroke. A ratio of 2.7 means, in simple terms: one millimetre of shock movement equals 2.7 millimetres of rear wheel travel. An average ratio gives a usable approximation; a ratio curve maps the progression per millimetre of shock stroke more accurately.

When is expert mode worthwhile?

When a leverage ratio curve is available for the bike. It replaces the average ratio and improves the basis for the calculation, especially with very progressive rear ends.

Is the calculated spring rate the final setup value?

No. It's a technically sound starting value. Manufacturer approvals, permissible preload, riding style, trail and a real-world test decide the final setup.

Where can I get the right spring?

You'll find coil springs for shocks in our shop, for example the lightweight SiCr springs from WPS. To the springs

Found your spring rate – what now?

The calculated spring rate is a starting value. During suspension fitting we use telemetry to check whether spring, SAG and damping really suit your trail.

Coil springs in the shop Suspension Fitting