About the Honda ST90
Mighty Dax identity, fork dimensions and separate front and rear brake applications.
The Honda ST90 Mighty Dax uses a horizontal four-stroke OHC engine. This guide focuses on its 1973–1975 fork seals, front and rear brake shoes, and individual clutch plates.
Build a brake and fork service order
Choose shoes for the brake position being repaired and compare the fitted fork with the 27 × 39 × 10.5 mm oil-seal pair. If the engine has been replaced, identify it before selecting clutch parts.
Model and year comparisonST90 parts differences
Use these model and component differences to narrow the correct parts for your motorcycle.
Front fork
27 × 39 × 10.5 mm seals
The fork oil seals fit ST90 1973–1975 and are supplied as a set of two.
Brake shoes
Choose the correct position
Separate front and rear shoe you can find ST90 1973–1975.
Clutch
Individual plate replacement
The clutch plate fits ST90 1973–1975 and is sold individually.
Prepare for the repairIdentify your ST90 components
Use these checks when a registration year or a model badge does not identify the fitted parts.
- ST90 designation and model year checked against the motorcycle and documents.
- Frame and engine markings, including known replacement-engine details.
- Fork assembly and full removed-seal dimensions.
- Front or rear brake position and the fitted wheel and brake assembly.
Contact PartsNMore with the model year, frame and engine markings, and clear photographs of the component being repaired.