Although the Valley of the Sun is a sprawling place, it's mostly flat and has numerous paved bike paths, which makes bicycling a breeze as long as it isn't windy or, in the summer, too hot. In Scottsdale, Arizona Outback Adventures/Wheels 'n Gear (tel. 480/945-2881) rents cruisers for $15 per day and mountain bikes for $30 to $50 per day. Mountain-biking trail maps are also available. This company also does half-day guided mountain-bike rides.

Among the best mountain-biking spots in the city are Papago Park (at Van Buren St. and Galvin Pkwy.), Phoenix South Mountain Park (use the entrance off Baseline Rd. on 48th St.), and North Mountain Preserve (off Seventh St. between Dunlap Ave. and Thunderbird Rd.). With its rolling topography and wide dirt trails, Papago Park is the best place for novice mountain-bikers to get in some desert riding (and the scenery here is great). For hard-core pedalers, Phoenix South Mountain Park is the place to go. The National Trail is the ultimate death-defying ride here, but there are lots of trails for intermediate riders, including the Desert Classic Trail and the short loop trails just north of the parking area at the 48th Street entrance. North Mountain is another good place for intermediate riders.

There's also plenty of good mountain biking up in the Cave Creek area, where you can rent a bike for $35 a day at Bikes Out West in Cave Creek, 6149 Cave Creek Rd. (tel. 480/488-5261). This shop also offers guided mountain-bike tours for $65 to $85. If you'd like a guide for some of the best biking in the desert, contact Desert Biking Adventures (tel. 888/249-BIKE or 602/320-4602; www.desertbikingadventures.com), which leads 2-, 3-, and 4-hour tours (and specializes in downhill rides). Prices range from $70 to $97.

If you'd rather confine your cycling to a paved surface, there's no better route than Scottsdale's Indian Bend Wash greenbelt, a paved path that extends for more than 10 miles along Hayden Road (from north of Shea Blvd. to Tempe). The Indian Bend Wash pathway can be accessed at many points along Hayden Road. At the south end, the path connects to paved paths on the shores of Tempe Town Lake and provides easy access to Tempe's Mill Avenue shopping district.