The waterproof Thunder Pant from Squamish-based 7Mesh is the most storm-ready we've tested to date, and we're confident Perun would give 'em the thumbs up.
Mountain bikers have been known to wear tight lycra shorts, cut off jorts, polyester baggies, khaki work pants, mesh basketball shorts, and just about anything else that's been available.
Mountain biking trousers like the Maloja MOMOSM are designed to keep the elements outside and feel similar to the cozy couch that your riding buddies are sitting on as you enjoy the trail.