From road biking in Rocky Mountain National Park, to 4WD roads and single track in surrounding National Forests, great mountain biking opportunites are all around Estes Park.
Trail Ridge Road was recently repaved and makes for incredibly smooth downhill cruising (about 25 miles worth from the top of the Continental Divide).
Estes Park Mountain Shop has bike rentals and repair, and knowledgeable staff who bike the trails every chance they get. They can help you find routes to match your ability and desire.
Crosier Mountain out of Glen Haven, and Halls Ranch out of Lyons are two locals favorite multi-use trails for mountain biking.
Although all 4WD roads are open to bikes, not all hiking trails allow bikes. Winter roads in Rocky Mountain National Park open first to bikers in April before opening to cars for the season. You can have Old Fall River road (dirt), and Trail Ridge Road (paved) all to yourself in the spring!
For a road bike trip of a lifetime, plan to take part in the Bicycle Tour of Colorado each June. 2014 Tour starts and ends in Gunnison and goes through Ouray, Durango, and Pagosa Springs. Limited to 1500 riders. This is a 7 day, fully supported bicycle tour in the spectacular Colorado Rocky Mountains.