The Iconic SILCA 24.1 gasket is the heart of the press-on Presta chuck. The current 242 gasket utilizes a high tech and very red, fully synthetic elastomer base material.
This unique bright red gasket borrows from industries which require air-tight seals in the harshest of environments. It tests to a life expectancy of more than 5X the carbon filled rubber or Buna-N materials used previously. New Two-Stage seal geometry seals on both valve stem and at the base of valve core threads resulting in a more positive seal and improved durability. The new gasket slips onto the valve stem with a satisfying 'click', while unique internal geometry actually utilizes line air pressure to compress the gasket onto the valve stem: the higher the pressure, the tighter the seal. This design is so iconic we've found more than 20 companies world-wide making pump heads and gaskets copied from this, but none of them can come close to the precision and technology of the SILCA 242.
Synthetic elastomer base material
5X the durability of traditional rubber
Two-Stage sealing geometry optimized for all Presta valve stems
Pressure amplifying dome geometry uses air pressure to clamp valve stem
Fits all bell-shaped SILCA Presta heads
9mm H x 21mm OD
Mfr Claimed Weight