If rain is a possibility, put a pair of lightweight waterproof RP-5 pants in the trunk of your bike. When folded they are very compact to fit in the smallest places. Long zippers allow for easy entry over boots and the adjustable waist cinches things up. Slip these pants over your riding gear and stay dry through the quick shower.

Great pants but was expecting them to be larger? To be safe, I would suggest buying a size larger than you usually wear.