Woodinville - Snohomish - Monroe - Duvall loop. Much of this is on the flying wheels 100 mile route, but not the Lk. Sammammish loop mentioned above. Variations of this are popular with local racing teams on saturday mornings. Obviously there are a million variations, but
here's one I like, 45 miles, start and finish at the redhook brewery (allows parking, on the samm. riv. trail, so easy to connect to). Easy to extend north for a loop around Lk. Roesiger or south to come up ames lake, tolt hill or other typical snoq. valley return routes.