Vertex Sherco Piston Kit - 250cc

The Vertex Sherco 250 Piston Kit is a replacement piston kit for compatible Sherco 250cc two-stroke trials motorcycles. Manufactured by Vertex, these pistons are designed for engine maintenance, piston replacements and top-end rebuilds.

Available in four piston grades (A, B, C and D), each kit includes a piston, piston rings, gudgeon pin and circlips.

Piston Sizes

Size A is the smallest piston grade, with each subsequent size increasing in diameter by 0.01mm. The piston grade is marked on the piston crown for identification.

Technical Specifications

• Piston diameters: 72.75–72.78mm
• Recommended piston-to-cylinder clearance: 0.024–0.035mm (2009 Sherco specification)
• Piston measurement position: 19mm above the bottom of the skirt
• Reference measurement temperature: 24°C
• Required little-end bearing: 18 × 22 × 22mm

Choosing the Correct Piston Size

Selecting the correct piston grade is essential for maintaining the recommended piston-to-cylinder clearance.

Cylinder wear may vary throughout the bore, so measurements should be taken at several points along its length and in both directions before selecting a replacement piston.

Vertex pistons are manufactured with a tapered and oval profile to accommodate thermal expansion during operation. For accurate sizing, the piston should be measured front to back, 19mm above the bottom of the skirt, at approximately 24°C.

Important Fitment Information

These replacement pistons require an 18 × 22 × 22mm little-end bearing. The older Sherco M043 bearing is not compatible and must be replaced where fitted.

Compatibility

Suitable for Sherco 250cc two-stroke trials motorcycles using the M009, M586, M587 or M588 piston specifications.

Please Note

Always confirm your existing piston grade, cylinder measurements and model compatibility before ordering.

If you’re unsure which piston size you require, please contact Road and Trials for advice.