2009 Chris Boedeker custom, 1988 Tommasini Prestige, 2007 Bill Davidson custom, 1985 Univega Gran Turismo; 1988 Specialized Stumpjumper
I don't own a Tricross but I see them with fenders all the time. I would think the proper size SKS or Planet Bike fender would fit fine and install in a few minutes. If you're riding in lots of rain a long mudflap, especially on the front fender, would improve their ability to keep you dry.
I have the Planet Bike Cascadia Hybrid/Touring fenders on my Tricross. They fit well but needed a little jury rig on the rear brake bridge bracket. If you have the Comp with the Carbon stays the included bracket is not long enough. If you have the sport with twin stays your golden, perfect fit. Either way they work well with my 700x35c Schwalbe Marathon Supremes and 700x35c Nokian W106 studded tires. http://ecom1.planetbike.com/7026_5.html