Sink some knobs into the mud with the Continental Cyclo X-King tire. It's got an aggressive tread that still manages to roll quickly in a variety of conditions. Rounded symmetrical knobs help maintain traction when climbing and braking in loose conditions. The shoulder lugs help you get some traction in the corners without slowing you down on days when the course is a little drier.
Aggressive traction makes these excellent for variable conditions
Rounded symmetrical center knobs provides traction for braking and climbing
Shoulder lugs help you keep a grip on the dirt when cornering