Pedaling tour a chance to do a good deed and get exercise while sightseeing.

There’s an easy way to take in the sights of the South Bay: Get in your car and drive.

But if you want to add exercise and challenge to the experience, you can grab your bicycle and join the Tour of the South Bay, which will get under way early Sunday morning in Redondo Beach.

The itinerary will cover the oceanfront in the three beach cities, the vistas from the Palos Verdes Peninsula and the commercial bustle of the Los Angeles and Long Beach harbors.

“It’s a gorgeous ride,” said John Kirk Jr., chairman of the third annual bike tour, which is sponsored by the Redondo Riviera Rotary Club to raise funds for club charities. The main beneficiary is the Exchange Club Center for the Prevention of Child Abuse in Redondo Beach, which the 60-member club helped organize three years ago. Volunteers from the center help families where child abuse has occurred or could occur.

The bike tour isn’t intended to be a speed or endurance run. Rather, says Kirk, it’s a scenic ride for cyclists, whether serious pedalers clad in form-fitting outfits or weekend cyclers in T-shirts and shorts. The only required attire for Sunday is helmets, which will be available on loan from the organizers. Entry forms are available at many bicycle shops and the Redondo Beach Chamber of Commerce, 1215 N. Catalina Ave.

A 25-mile route encompassing the three beach cities and the peninsula is designed for the casual rider. A more demanding 50-mile ride, which adds the harbor area and Long Beach, is slated for seasoned cyclists.

Although everyone will start from Torrance Beach near Riviera Village, there’s no official finishing time. “Some will crank along, taking four or five hours for the tour,” Kirk said.

A highlight of the longer tour will be biking over the Vincent Thomas Bridge in San Pedro, which normally is closed to bicycles. The Gerald Desmond Bridge in Long Beach also will be used, and some traffic lanes on both bridges will be closed to automobiles. “Bikers will have a lane to themselves and can stop and look out over the harbors,” Kirk said.

San Pedro cyclist Rick Perkins said he has covered most of the South Bay in his five years of riding, but crossing the bridges on Sunday will be a first. “They have climbs and that will make it more challenging,” he said, adding that a San Diego friend is coming up for the ride just because the bridges are included.

Kirk said the Rotary Club started the tour three years ago as an unusual way to raise funds for its charities, which also include the Redondo Beach Salvation Army Meals on Wheels program.

This year’s tour is a departure from the first two, which began and ended at the velodrome at Cal State University Dominguez Hills. Much of the previous route was inland and did not include the beach cities. Kirk said he hopes between 800 and 1,000 cyclists will turn out this year.

Although people can take a scenic ride on their own for free, Kirk said the bike tour is aimed at those who want to help a charitable cause and enjoy their hobby with hundreds of other enthusiasts.

“People can ride with other people, have some fun and have the camaraderie of doing something as an event, as opposed to riding on their own,” he said.

During the tour, about 140 volunteers will be stationed along the route to support the riders, who will be provided with souvenir bibs and caps. Fruit, cookies and water will be dispensed at refreshment stops every 12 miles.

Mechanics in vehicles will cruise the route to help cyclists repair bikes that break down. First aid will be available for minor mishaps. Afterward, riders can buy pizza and barbecue at Torrance Beach.

More than 200 people have signed up already for the Sunday tour, for which registration will open at 6:30 a.m.

Heike Leason of Hermosa Beach, already on a weight-loss program and working out, said she would rather ride a bike than run as a part of her effort to get in shape. She said the tour appealed to her because, “It’s so close to me, there are really ideal conditions to ride in, and I love that view around the Palos Verdes Peninsula.” She rode 40 miles on Thursday just to get ready.

For Letty Austin, who plans a 208-mile mountain bike trip, the Sunday run on pavement will seem like mild exercise. “I want to get 50 miles in at a fairly fast pace,” said the Manhattan Beach woman, who hopes to finish in three hours.

Matt Carroll of Redondo Beach has been bicycling for only four months and said this will be his first group trip. “It’s a chance to meet some new people and get good, healthy outdoor exercise,” he said.

What: Tour of the South Bay.

When: Sunday, 6:30 a.m. registration; 8:30 a.m. start.

Where: Torrance Beach parking area, Esplanade and Calle Miramar, Redondo Beach.

Admission: $28 entry fee.

Information: 371-5066.