Now, Hold on a Dadburn Manitou SPV Minute, will ya?

Manitou's new Minute 2:00 fork featuring Stable Platform Valving. Photo: Sterling Lorence

Early this spring, the folks from Manitou corralled members of the mountain bike press near the trails of South Mountain in Phoenix, Arizona, for some singletrack ripping and new product brainwashing. While it could be argued that shepherding a group of bike journalists is roughly as productive and ultimately as frustrating as being the short bus driver at an ADHD-filled special needs kindergarten picnic, Manitou’s ruling elite decided that they had something newsworthy enough to run the risk of playing caretaker to a group of drunken hacks. The newsworthy item? A new compression damping technology called SPV, short for Stable Platform Valve.

Before we get into where you can find the SPVs, we’ll try to explain what it is. Compression damping, the control of oil as suspension is compressed through its travel, is traditionally handled by oil flowing through a valve. The flow of that oil is usually governed by a stack of thin shims, the fluctuation and deflection of which determine (in addition to the size of the valve and the viscosity of the oil) the level of damping in a given component. Thicker shims are harder to displace, and tend to make for stiffer damping, thinner do the opposite. Now, with the introduction of SPV (the genesis of which can be found in Chuck Curnutt's work with three-foot travel desert race trucks), that compression shim stack has been replaced with a pair of overlapping aluminum cups. About the size of a 10-mm tall stack of nickels, they fit into one another, and the resultant atmospheric pressure trapped in between causes them to naturally push apart, no springs, no shims. They are mounted on the compression side of the damper valve. In static state, at the top of a suspension's travel, the cups are held closed against the valve by air pressure on the oil in the damper, preventing oil flow. Depending on the level of air pressure, it's possible to tune out low amplitude forces, like pedal-induced bob, and create a breakaway threshold from which the shaft begins moving through its travel. More air pressure on the oil will make for a higher breakaway threshold, less air will make for a plusher initial state, but with more resultant pedal bob.