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Suspension & Setup

Rider Sag Calculator

Front and rear rider sag together. Enter fender-to-axle (or a zip-tie on the fork stanchion) for each end.

Inputs
Results
Live

  • Rear rider sag

    102mm

  • Front rider sag

    90mm

  • Front % of travel

    29.0%

  • Rear % of travel

    32.4%

  • Rear minus front

    12mm

    Ends are reasonably matched

Formula

Sag = extended − rider · Balance = rear sag − front sag

Related calculators

Sag
Sag is how far the bike settles from fully extended. Measure from a fender mark to the axle with the bike on a stand, then on the ground.
Race Sag
Race sag (rider sag) is measured with the rider in full gear, balanced on the pegs. Most MX bikes want about 100–108 mm on ~310 mm travel.
Static Sag
Static sag is bike-only, no rider. Too little static sag with correct race sag means the spring is too soft (you used a lot of preload). Too much static sag means the spring is too stiff.
Spring Rate
Estimate fork and shock spring rates from rider weight, sag targets, and linkage leverage. A starting point for ordering springs — not a replacement for a tuner.