A ride I like to do it start in Marymoor park in Redmond and ride the Sammamish trail (paved) connects onto BirkGilman trail around lake wasington into Seattle. Instead of riding back on the same trail you can catch the #545 Bus on 520 right across the University bridge by Husky stadium (bus stop is on freeway) and it will bring you back to Redmond. Its about a 30 mile ride and can be done in about 4 to 5 hrs depending on how much site seeing you do. A little side trip to Gas works park on the Birk Gilman trail is worth the ride and is about 3 miles extra riding. The ride is all flat, lots of parks and places to stop and good views on a well paved trail.