Review on Progressive Suspension 12 1201B Powder Pressure by Gary Zielinski

Excellent shock absorbers. The damping is not adjustable, but the rear wheel is easy to control. The Progressive's recommended spring rate feels a bit light, so I'd recommend using their spring rate for heavier applications, especially if you're carrying a passenger. This is my third set of progressive shocks (three different bikes) and the improvements have been constant. Not sure about durability - 5000 miles on just one bike and 300 on the other (the first was sold a long time ago) but for a reasonable price they work well. These aren't the bikes I've ridden at the track, but they're fine for general road riding, including more energetic mountain riding.