2PCS 40mm Bicycle Tubeless Presta Valve Stems – Aluminum Alloy French Valve Core Nozzle for Road Mountain Bicycle Tire Replacement(Black)

40mm tubeless Presta valve stems provide a reliable solution for maintaining optimal tire pressure in road and mountain bike tubeless systems. These aluminum alloy valve cores ensure consistent air retention during rides across varied terrains.Installation takes only minutes: First verify valve core tightness. Take off the lock nut and O-ring before inserting the stem through the wheel's valve hole. Position the O-ring on the stem shaft before securing with the lock nut. Final tightening creates an airtight seal between the silicone base.Specifications:Material: Aluminum alloy with silicone baseStem length: 40mm/1.57 inchesTotal length: 52mm/2.0 inchesCore diameter: 5.75mm/0.2 inchesBase diameter: 12.8mm/0.5 inchesValve type: Presta (French valve)Weight: 11g/0.4oz per stemColor options: Black, Purple, CoffeePackage includes two complete tubeless valve stem sets with all necessary hardware for immediate installation.

• Durable Hybrid Construction‌: Combines lightweight aluminum alloy with flexible silicone for superior durability and vibration resistance in all riding conditions.
• Precision 40mm Design‌: With 52mm total length and 12.8mm wide base, these valves ensure secure fit for most tubeless setups (road & mountain bikes).
• Enhanced Air Retention‌: Oversized silicone base creates superior seal, avoid air leakage even on rough terrain and long-distance rides.
• French Valve Compatibility‌: F/V style Presta valves work seamlessly with tubeless systems; includes removable cores for easy pressure adjustments.
• Complete 2-Piece Kit‌: Comes with all necessary components for quick installation (O-rings, lock nuts); available in stylish black/purple/coffee colors.