The Madone 9 will be very difficult to fit a full fender on. About the only thing I can think of is the SKS Racer Blade Long. I have a set of Crud 2's from my previous bike, but there's no way to attach at the fork crown or seatstay bridge because of the proprietary brakes.
You should do like most Madone owners who ride in bad weather and use a different bike for bad weather. ;-)
A forum community dedicated to Road Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, troubleshooting, maintenance, and more!