TEN THINGS YOU NEED TO KNOW ABOUT SUSPENSION SERVICE
(1) As hard as it may be to believe, profit was one of the primary motivators in the design of your bike’s suspension. The manufacturers don’t want your bike to have the best suspension. They want it to have the best suspension they can afford. When saving a buck filters down to shock and fork hydraulics, it means less-than-optimal suspension fluid and over-engineered components. But, if your bike has adequate suspension, it will perform at the status quo level for a full season.
(2) Suspension hop-up shops improve performance partly through reducing stiction. Making parts move easier means using thinner piston bands and fewer sealing O-rings. Modified suspension does more work with less, and thus requires more frequent service.
(3) The increased load on modified suspension seals and bushings is mostly offset through the use of higher grade suspension fluid. When Pro Circuit, Enzo, Factory Connection, RG3 and others modify your suspension, they use the highest quality components and fluids available.
(4) The biggest difference between OE and aftermarket suspension fluid is stability. Performance fluid will have the best viscosity index, and the thickness of the oil, as well as fork and shock damping, will remain more consistent at the
(5) Hot rod suspension fluid is petroleum-based, as is the stock fork and shock oil, but the manufacturer used standard-base petroleum. The fluids that hop-up shops use are always a step or two better (Group 2 or Group 2+ base oil). Aftermarket fluid includes the best polymers to keep the oil viscosity stable when hot. It also has the best additive system, including anti-wear, anti-foam, extreme pressure,
anti-stiction and anti-corrosion modifiers.
(6) The biggest misconception people have is that changing the fluid in a worn shock or fork is enough to fix its flaws. It isn’t. Think of your suspension components as though they were a burnt clutch. New oil won’t make a burnt clutch work. The same can be true of the internals of your forks or shock.
(7) Valving shims lose their snap over time. The snap, or resistance to bending, is what controls the ebb and flow of compression and rebound damping. When the shims wear out (lose their snap), the suspension boings. How do you know if the shims have worn out? First, you can feel it when the shocks or forks start pogoing. Second, you can calculate how many hours the shims have on them. Actually discovering the wear is difficult, which is why you need to be a pro to discover losses that are measured in thousandths of an inch. New seals, bushings, O-rings and shims are required to bring old suspension back to spec.
(8) Forks operate at 110 degrees Fahrenheit and use a 5w suspension oil. Shocks operate at 300 degrees and use a lighter 3w oil.
(9) Your suspension maintenance schedule depends on how you ride. After 20 hours, the suspension components of a fluid rider might look brand new. But, an aggressive rider will wear the shock and forks out in 20 hours. Additionally, sand tracks, whoops and square-edged bumps break down shims and fluid quicker than hardpack circuits. Muddy tracks and sand wear out suspension quicker than other track surfaces.
(10) If you have an hour meter for your engine, start using it for your suspension. At 20 hours of riding, have a suspension specialty shop service the forks and shock. If the bike feels like a brand-new motorcycle when you ride again, it tells you that the suspension should have been serviced at the 15-hour mark. There is no doubt that you can ride your suspension for as many hours as you want, or only have the suspension worked on when a seal starts to leak, but this is wrong. Periodic maintenance not only improves the quality of the ride, but makes those expensive forks and shocks last longer (remember it costs over $1000 to replace a shock).