How a 9-stage adjuster changes the push, shown on an illustrative cutaway of a Tough Dog foam-cell shock.
Fig 1Nine stages← → stage · space push · c cleartap knob · tap rig to pushstage 1 of 9
Bypass needle, set by the knobPiston, shims and rodOil flow (illustrative)Foam-cell sleevePen trace, one line per pushA Tough Dog 9-stage adjustable foam-cell shock, cut away and standing in a test rig. Each click of the knob moves the bypass needle. The more of the bypass it closes, the more oil has to go through the piston's shim stack, so the same push travels slower. The ram pushes at the same pressure every time (watch its gauge), and a pen on the crosshead draws each push on the chart: the slower the push, the further its line runs across. Diameters follow Tough Dog's 40 mm adjustable: 40 mm bore, 18 mm rod, 60 mm casing. The internal layout and the motion are illustrative, not measured. Stage 1 is the softest here: check the markings on your shock.