By Pat Gerber, Founder, HD Shocks ·
The short version
A shock controls how fast your suspension moves. It does that by pushing oil through small holes and stacks of thin steel washers called shims. The harder the hit, the more the shims bend open. That resistance is what keeps your rig from bouncing and rocking.
Why oil and gas have to stay apart
As a shock works, the oil gets hot and the shaft pushes into the body, taking up room. Most shocks use a gas charge to make up for that room and keep pressure on the oil. In a cheap shock the gas and oil can mix. The oil foams up, and foamy oil can't control anything. That's the fade you feel on a long, rough stretch of highway.
What the floating piston does
An IFP, or internal floating piston, is a sealed piston that rides free inside the shock body. Oil on one side, nitrogen on the other. As the shaft goes in, the floating piston moves to make room and the nitrogen compresses. The oil never touches the gas, so it never foams. You get the same damping on the first bump and the five hundredth.
Why a monotube body matters
A monotube has one large tube instead of a tube inside a tube. That means a bigger piston, more oil and more surface to shed heat. HD Shocks use a bigger body than the factory shocks and a 3/4 inch shaft.
Remote reservoir and piggyback
On our reservoir shocks the floating piston and nitrogen move out of the body into a reservoir. That leaves the body full of oil, so there's more oil to soak up heat. A remote reservoir connects with a hose. Our 3.0 billet piggyback bolts the reservoir right to the shock through a solid billet bridge.
Want to see it work? Watch the cutaway on our Technology page.