TOUR DE SAN FRANCISCO

With its compact size, several outdoor stairways and 40 hills to climb, most would agree that San Francisco is a walker's city. So, the mention of it as a mecca for bicycle enthusiasts might raise a few eyebrows.

But, if you appreciate a good bike workout, you'll find San Francisco the perfect uphill battle. Just put on a helmet, cycling shorts, a windbreaker, sunscreen and sunglasses and you're all set to begin a bike tour of San Francisco.

On any route, cyclists can take in colorful neighborhoods and spectacular views. With its scenery, flat areas and mild grades, this city of 47 square miles offers a variety of challenging courses for the beginner or advanced rider. Here are several "must-ride" areas as suggested by City Sports and Bicycling Magazine and Start to Finish Mountain Bike Tours:

* Golden Gate Park. On Sundays, John F. Kennedy Drive is off limits to cars, allowing for 7.5 miles of cycling. Be careful of rollerbladers who share the road. Some points of interest are the Japanese Tea Garden, Asian Art Museum, California Academy of Sciences, the Dutch Windmill and Stow Lake.

* The Golden Gate Bridge. It's more than a mile and half across, and with heavy winds, the ride can be quite a workout. Monday through Friday, the east walkway is open to cyclists and on weekends, it's the west walkway. On the Marin side at the end of the Vista Point parking lot is a bike lane parallel to Highway 101 which then turns off to Alexander Avenue. The road winds through Sausalito offering a great view of the Bay.

* The Marin Headlands. Go back up Alexander Avenue, under Highway 101 and into the Marin Headlands. The uphill climb may be tough on the legs, but the spectacular view of the city, bay and Pacific Ocean will make the trek worthwhile. The one-way distance from the Vista Point parking lot on the San Francisco side of the bridge to Sausalito is about 3.5 miles.

* The Marina District, in the northern part of the city, offers several art deco buildings, the Palace of Fine Arts and the Exploratorium; the sidewalk in Aquatic Park offers a flat area for beginning riders. Keep biking west of the Palace of Fine Arts and you will find the 1,400-acre Presidio, newly converted (since October 1994) from army base to national park. Several roads go through the Presidio's greenery, which offers a park-like atmosphere with large, thickly wooded areas. While riding along Lincoln Boulevard in the Presidio, check out the great views of the Golden Gate Bridge and Marin Headlands.

* With its three bicycle lanes, the flat three-mile sidewalk along Ocean Beach (Great Highway) provides a good workout and can be incorporated into a longer tour of the Sunset District. Ride south on the Great Highway for two miles past the San Francisco Zoo to Sloat Boulevard and turn right onto Lake Merced Boulevard, then ride the five miles around the lake and nearby golf courses.

* An added challenge for Great Highway bikers is to ride north from Lake Merced toward the Cliff House, and prepare for a 200-foot ascent. Veer right onto Point Lobos Avenue after passing Seal Rocks in the Pacific, then turn right on 43rd Avenue and coast downhill to Golden Gate Park and enter at Chain of Lakes Drive East, which takes you back onto John F. Kennedy Drive.

* For those courageous enough to venture into the Financial District, weekends are best (when traffic is light). Bicycles with wide tires are recommended because of the cable car tracks.

* Along Fisherman's Wharf on the northern edge of the city, riders can pass by tempting seafood stalls and retail complexes, then continue west towards Aquatic Park, with Hyde Street Pier and its antique boats. Be warned, though, that crowded conditions on weekends may force cyclists to get off their bikes and mingle with the pedestrians. Be sure to cross cable car tracks at a right angle!

* For a whole day's journey, follow the 49-Mile Drive, mapped by the San Francisco Convention & Visitors Bureau. Begin at the Civic Center and look for the "49-Mile Scenic Drive" signs which will take you around most parts of the city.