"After all," says Frank Ridge, "life is an endurance test."

That's why he figures that doing something like biking across the country -- about 100 miles a day for seven weeks -- transfers so well to the real thing.

"There's a tremendous carry-over," says Ridge, 67, a McLean financial consultant who happened to mention to his middle daughter a couple of years ago that he'd like to bike across the United States before he was 70.

Julie, 33, a New York actress, writer and also a big believer in endurance feats as life metaphors, called him back several days later: "Dad, let's do it."

By around noon on Thursday they will have done it, along with about 60 others on the Pedal for Power Across America Ride sponsored by the League of American Wheelmen (LAW). With the symbolic dipping of the front wheels of their bikes into the Atlantic Ocean in Boston they'll have covered 3,341 miles in 47 days.

The group also will have raised about $500,000, divided among LAW's educational and legal foundation and the riders' chosen charities. (Each biker must raise a minimum of $5,000 in sponsor pledges; Ridge has raised more than $20,000.)

But beyond all the hype and prestige and good works associated with the ride -- such things as a total stranger handing over $100 for cancer research at a rest stop somewhere in New Mexico, or one woman biker's ride to buy special equipment for handicapped skiers -- beyond all that public pedaling, is a pedaling for personal power that every biker must feel.

And every biker will have his story, a deeper, private mystical story that transcends the public anecdotes about keeping going despite the flu, torrential downpours and scraped knees.

Frank Ridge's real story was written on Father's Day in Ohio when he was biking alone on bad roads, pumping up endless hills with a swollen knee twisted in a fall and throbbing with pain.

"That was when I was asking myself, 'How much can I stand without breaking?' "

This is a man who has biked virtually all over the world, including a 530-mile tour of Israel, has broken his collarbone while biking and regards pain as "a relative thing."

He also had decided that if he could survive the longest day, 116 miles from Wickenberg to Prescott, Ariz., on Day 4 of this trip, "I'll make it."

When daughter Julie spotted him on Father's Day, she wasn't so sure. " 'It's time, Dad,' " she insisted, " 'for a Power Bar stop.' "

She later told her dad that he looked extremely pale and she and others were worried. But because she knew his feelings about the "sag wagon" -- to be avoided, but if absolutely necessary, every mile would be made up -- she warned everyone not to mention it.

Somehow, with the help also of a Dairy Queen milkshake, Ridge made it through and over that long day's night.

"I couldn't believe it; something happened, and I wound up sprinting the last 10 or 15 miles home," said a triumphant Ridge last week from a motel stop in Pennsylvania.

There was a Father's Day cake awaiting him that night in Wooster, Ohio, and a proud daughter behind it.

It was her turn to provide the support. "He's always been there for me."

Which means, for example, that Ridge was on a boat when his daughter became the first person, in July 1983, to swim two consecutive laps around Manhattan Island (57 miles), and when, in August 1985, she swam a lap around Manhattan Island each day for five consecutive days, earning her a place in the "Guinness Book of World Records."

And he was there when she completed the Hawaii Ironman Triathlon in October 1984.

Not only has he been there for her. "My dad," she declares, "has amazing calves." There are rumors that she was behind Ridge's "Best Body Over 50 Award" bestowed during lighter moments on the Pedal for Power trip.

"I know," says dad, "I wouldn't have made it without Julie's training program."

Julie Ridge, whose husband joined the group once in Arizona, considers this trip "my last hurrah of sorts before I have a baby." She's writing an article on the experience for McCall's, and don't be surprised if dad's prose appears somewhere. He's kept a full journal, right down to vivid personality descriptions of fellow bikers whose occupations range from fireman to doctor, with an age span of 19 to 73, married and single, about equally divided between men and women.

Some of the best riding? Kansas. "There's something very lovely about the flats," says Ridge, "with the wheat fields like waves of an ocean on either side of the road."

Perhaps the most spirited hospitality was in Niles, Ohio, where the bikers were given a police and firetruck escort into town and were shuttled back and forth between the motel and a yogurt place.

Before Ridge left on the trip, he mused, "My peers tell me I'm out of my mind, and you know, I like that. I've been very responsible and dependable, and I think it's great that I'm still capable of doing something 'crazy.' Put that last word in quotes."

And his daughter writes in her book, "Take It to the Limit" (Rawson Associates):

"The greater the obstacles along the way, the harder the road, and the more desperately you want to quit -- the sweeter the taste of finishing. There is tremendous joy there. It is a land of determination, of conquering, of challenge. It is a land worth visiting."

Says dad now: "There are days when your spirits are soaring -- you're flying with the angels -- and others when you're saying to yourself, 'What in God's name am I doing out here?' "

And now if you want a chance to look at yourself out there, next year's Pedal for Power Across America trip is May 11-June 27, 1991.

If that's a little ambitious, there's the Pedal for Power North-South trip Sept. 22-Oct. 13, from Portland, Maine, to Orlando, Fla. -- 1,562 miles in 23 days.

For more information: Pedal for Power Associates, P.O. Box 898-F, Atkinson, N.H. 03811. Or, (800) 762-2453, or (603) 382-2188.

'Race for the Cure'

"Fighting breast cancer is a family matter," Vice President Dan Quayle has said. To demonstrate that belief, the Quayles and their children all took part in the first annual Komen/Washington "Race for the Cure."

The Quayles, who were honorary chairmen of the 5k run/walk June 16, joined what has been termed "a stunning turnout" by race officials, about 8,000 men, women and children. The event raised about $400,000 for research, diagnosis and treatment of the disease.

Stressing the need for family involvement, Marilyn Quayle has written:

"I am fortunate to have a husband who takes to heart the scriptural injunction to care for your spouse as for your own body. But not all women can take that for granted. Real men don't hide from medical science, don't judge by cosmetic circumstances and don't devalue anyone because of sickness."

Mrs. Quayle, whose physician mother died of breast cancer at age 56, has adopted breast cancer, especially early detection, as a priority project. She and the Dallas-based Susan G. Komen Foundation, which now sponsors 10 "Race for the Cure" fund-raisers around the country, have a goal of making mammography more accessible in the District and elsewhere, especially for low-income women.

A number of VIPs, including cabinet members, ambassadors and congressmen, participated in the run. But Transportation Secretary Samuel Skinner gets the prize for the biggest contingent: 1,000 runners from his department.

And the vice president's 5k time? Just under 25 minutes.

Don't tell his boss.