Over the years, ARI has discovered the key role of a separating lubricant between the fork tube and the rubber of the oil seal to reduce to a minimum the surface friction, without affecting the function of the oil seal. After exhaustive testing, ARI chose a lubricant which is produced in the USA, and devised specifically as a rubber/metal lubricant for mechanical components used in the NASA space program. The advantage of this special grease, which they call ARISIL, is that it extends the life of the oil seal, and helps it retain its vital characteristics of flexibility and chemical resistance. For this reason, every set of ARI FORK OIL SEALS contains a single dose sachet of ARISIL, sufficient to lubricate the two oil seals supplied.

In applications where they are supplied, the ARI "ARIMER" foam rings combine a mix of open and closed-cell polyurethane foam. This creates the perfect formula; the open cells absorb and retain the lubricating fluid whilst the closed cells ensure an excellent elastic return. Working in tandem, the closed cells release the fluid from the open cells, improving the lubrication of the fork tube overall leaving a smoother action.