The ideal candidate.
Clement's PDX Clincher Tire has one of the most demanding job descriptions in cyclocrossery: Must love mud without sacrificing speed while maintaining a gap on hardpack. Fortunately, it's also got the perfect resume for meeting those requirements.
Since it's a clincher, this PDX loses the ride quality battle with the tubular model; however, it does drop a few grams and is also a helluva lot more convenient and economical. While it won't match the peerless feel of tubs, the clincher version does have the same sidewall reinforcement and, most importantly, that signature PDX tread pattern.
With taller, more widely spaced knobs than Clement's revered, all-conditions MXP, the PDX has its focus on looser, wetter courses — it is, after all, named after the airport code for Portland, OR, a city whose 'cross scene is as healthy as her courses are notoriously nasty. The semi-connected center rib provides just enough of a rotor to keep things straight in the muck and reduce rolling resistance when you hit the pavement or hardpack. The tire's real star is the shoulder, where siped, square-edged knobs bite aggressively throughout the arc of sloppy turns and when the tire sinks into softer earth.