The Ohlins AP750 STX 46 Supersport rear shock for the Aprilia RS 125 is built around a track-focused damping package intended to improve chassis control and rear tyre contact under load. It uses a gas-pressurised, oil/gas separated design to maintain consistent damping behaviour as temperatures rise. The construction is aimed at predictable feel and repeatable setup changes rather than broad, generic comfort tuning.

Ohlins | Made to race, perfected to ride

Developed from Ohlins racing experience, the STX Supersport line is intended to give clear feedback at the limit while remaining practical for regular servicing and setup work. The emphasis is on stable support through corner entry and controlled drive on exit, with tuning range aimed at riders who actively adjust their suspension.

Design architecture

This is a monotube STX layout with a separated gas chamber, helping reduce cavitation and keep damping response consistent. The unit is designed as a direct rear replacement for the RS 125 application, with damping and spring fitment matched to the shock format used in the bike’s rear linkage.

Adjustments & what they change

Rebound damping adjustment is provided to control how quickly the shock extends after bumps and after weight transfers, influencing stability on corner exit and how the rear follows the track surface. Compression damping adjustment is included to tune support under acceleration and when the rear is loaded, affecting grip, squat behaviour, and how the chassis holds its attitude through faster corners. Ride height adjustment is also included, allowing geometry changes that can alter turn-in character and mid-corner balance.

Factory baseline intent

The supplied baseline is aimed at a supersport use case where damping control and rear-end support are prioritised. It is intended to provide a structured starting point for rider preference, tyre choice, and circuit conditions, with the adjusters used to refine feel rather than compensate for incorrect springing or geometry.

Setup considerations

Any change to ride height should be approached methodically, as it can affect steering response, stability, and chain/swingarm angles. Compression and rebound should be adjusted in small steps and evaluated separately to avoid masking cause and effect. If you are changing tyres, track surface, or load (rider weight/gear), rechecking sag and then rebalancing damping is recommended.

Serviceability & lifecycle

The shock is designed to be serviceable, supporting routine oil and seal maintenance to keep damping consistency and seal integrity. Regular servicing is especially important in track use where heat cycles and contamination can accelerate oil degradation and seal wear.