Beta RR 390 4 T Race [2025-2026] - Piston Kit

PROX piston kit for Beta RR 390 4 T Race

The PROX piston kit is designed as a coordinated piston solution for the Beta RR 390 4 T Race from the years 2025-2026. The forged aluminum piston combines the piston replacement components included in the kit into a common assembly.

Function and execution

The standard piston compression design supports a clear selection based on the specified engine data. The “Flat with hollow” specification describes the specific design of the piston. With the compression ratio of 12.5:1 and the marking “4T”, the component is clearly classified for the specified four-stroke application.

Technical data

• Brand: PROX
• Material: aluminum
• Piston Type: Forged
• Piston compression: standard
• Diameter Ø: 87,980 mm
• Letter oversize: C
• Oversize: +0.02
• Compression ratio: 12.5:1
• Stroke: 4T
• Specificity: Flat with hollow

Vehicle assignment

The PROX piston kit fits the Beta RR 390 4 T Race, built between 2025 and 2026.

Scope of delivery

The kit contains the piston, piston rings, piston pin and circlips. The individual parts included are therefore combined for the intended piston assembly.