Keep the seal strong with Silca's 731 leather washer
The 731 is the classic 28mm diameter washer used on pumps produced between 1917 and 2008; since 1917 all Silca pumps have used steam pressure-formed leather cup washers to achieve high pressures.
Since the 1960's all SILCA leather washers have come from the same leather converting house in the fashion district of Milan, Italy. For more than five decades the same supplier has cut these washers from the excess material left over from the production of exotic handbags, Italian luxury cars interiors, and high-fashion luggage. A small press is used to hand cut and then pressure form these washers from pieces of leather otherwise sent to the trash.
From a purely functional standpoint, inexpensive o-rings are most commonly used in this application, but no o-ring can match the smooth feel and zero-stiction action of a leather gasket. It is common today to find SILCA leather gasket pumps throughout the professional peloton (especially during the spring classics) as o-ring seal pumps struggle with heat and often are unable to seal once the pump barrel is hot from inflating more than a few wheels.
Fits 28mm internal diameter Pista and Super Pista pumps (pre 2008)
Made from finest quality full grain leather
Produced by hand on the same equipment continuously since 1960
Updated from 2.25 to 2.50mm thick leather for improved durability
Hand crafted in Milan, Italy