F-O-A Shock Seal

Arguably the most important component in a shock absorber is its seal. The seal keeps the hydraulic fluid in and just as importantly everything else out.

The seals on hydraulic rams were well known and established for many years before the high-performance off-road shock absorber market came into being. And while the tolerances and components are still similar to hydraulic rams, there are some major differences.

A hydraulic ram pressures are often much higher than that of a shock absorbers and the ram’s shaft speeds are only a fraction of the shock absorber shaft speed and those two dynamics make the difference. A shock absorber shaft speed can be easily reach up to 20 feet/sec.

F-O-A shock seals has evolved over the years to its present position as the industry leader, and are becoming the standard for the best available shock absorber seal. Yes, it cost more to make them, but at F-O-A we believe, in the long run, it is more than worth the extra cost.

F-O-A was the first to use a double O-ring for sealing the seal head outside diameter in the shock tube. Unlike hydraulic rams, shock absorbers internal pressures vary thousands of times a hour during operation. That pumping of the O-rings can cause the O-rings to fail, using two of them stops the outer ring from pumping and enables it to last a very long time, as the pumping pressure doesn’t undermine the inner O-ring sealing.

F-O-A was the first to use a “bypass oil flow circuit” that allows oil to flow to the seal even under very high rates of compression shaft speeds. This allows the Teflon lined shaft bushing to last basically forever and it keeps the seal form experiencing a low pressure event that can cause dirt or even air to enter your shock along the very fastmoving shaft events.
F-O-A is the only major shock manufacture to have a standard longer 1″ shaft bushing to give more support to the shaft, centering it in the seal and seal head, keeping the shaft aligned, and far less likely to bend under very heavy-duty use.

F-O-A is the only major shock manufacture to use a “Three-piece-seal” head. With the three-piece design, when we assemble and you maintain your shocks the seal loading pressure can be adjusted as needed for your terrain, your ware and your ambient temperature.

F-O-A shocks can be ordered with Urethane Poly-pak B lip seals or Viton for high temperature applications. We use stainless steel hardware and Exterior black anodizing for protecting against, water, sun and the fun of the trail.