THERE WAS no doubt that I was leaving the city behind. I rolled past Old Licksville Road, and Sugar View and Windswept Farms. I passed a painted cardboard sign: "LIVE BAIT -- Nightcrawlers chicken livers antiques." I have been wanting to "get away" and finally I was doing it. I was pedaling 45 miles to Harpers Ferry on a 10-speed I borrowed from my friend's roommate's brother's roommate.

The Potomac Area Council of American Youth Hostels Inc. sponsors overnight bike trips to the Harpers Ferry hostel in spring and fall. The trip is a favorite of veteran bicycists, as well as an ideal first-time tour for someone who has two good wheels and two good legs. The AYH trip leader provided the 24 of us with maps and snacks for the road, and an AYH volunteer hauled our overnight bags to the hostel in the "sag wagon."

I was one of those first-time bicycle tourists, and I figured I had both the bike and the legs for this trip. That was before we got into what tour books tend to call "gently rolling hills." Other terms suggested themselves to us.

There was one slope the regulars kept talking about. They called it "The Wall." I was wobbling my way up the hill I knew I had to be The Wall when my friend, also a hardcore beginner, told me her philosophy:

"One of my favorite sayings is something Nietzsche said," she puffed. "Something like: 'What doesn't kill you only makes you stronger.' " Topping the rise, we faced the daddy of the hill we'd just climbed. Three hills later we reached the great-great grandad of them all, The Wall, which is about the time we reached the philosophy that it is better to live than die. We got off and walked.

Beyond these hills, in the middle of nowhere, there is a place called Pia's New York Style Pizza and Subs. Members of the tour gathered outside and claimed a patch of grass for a prolonged bask in the sun. Eventually a few of the hardier souls went for a dip in the river, led by the tour leader, a 54-year-old physicist who wore very pink biking tights.

Pink tights aside, this touring party didn't look like a group of people you'd expect to see cycling 45 miles through these hills. One man had his four-year-old daughter in a bike seat behind him. Deciding her dad could use some help, Laura leaned forward on the hills, pressed her face against his coat and kissed his back.

"Daddy!" she chimed, "guess who's kissing you!"

"A squirrel?" he said.

She passed some of the day with her coloring book, asking dad to hand her one crayon at a time. As they cycled away from Pia's, her helmeted head bobbed tiredly, but she still gave us her bright beam of smile and a wave.

Another father-daughter pair did the trip on a tandem bicycle. Lynn, one of the tour organizers, rode with Cliff, her father. He completed a bike trip from Missouri to the Atlantic coast on Thursday, took Friday off, and then joined her Saturday for the tour to Harpers Ferry.

At last we converged on a big house on a wooded hillside near the Appalachian Trail and the C&O towpath. For twenty years the Potomac Area Council had rented the building from the Kiwanis Club for $1 a year. The council recently purchased and renovated the site, and after all these years can officially call it the Harpers Ferry Youth Hostel.

The trip was a bargain at $55 for AYH members ($60 for nonmembers). The price included two days' room and board, not to mention atmosphere you could bite off and chew. I enjoyed the year's first pumpkin pie, hot apple cider and a crackling wood fire. Carl, the "hostel parent," brought out a banjo; someone else plied a synthesizer, and we ranged from "Oklahoma!" tunes to the Grateful Dead's "Friend of the Devil." The weekend felt complete with a Golden Lab named Barkly and kids climbing all over us in a long-running game of hide-and-seek.

There are several phenomena special to this trip that deserve mention. I gained weight, for which I blame Mike, who does the cooking on this tour. He had the nerve to serve us things like honey-baked chicken and mozzarella pasta-stuffed tomatoes for dinner, and things like Welsh rarebit, sausage and cantaloupe for breakfast.

Not only can he cook, he got the kids staying at the hostel to eat the scallops-and- mushroom dish he created the second night. When they made their faces, I was thinking "Give them hotdogs -- I'll eat their scallops." He told them it's the next best thing to peanut butter.

"What's in it?" one boy asked defiantly.

"Dead slugs, rotten things, bats," Mike told him. The kid grinned and stuck out his plate.

Another strange development on this trip was that people's conversations steered away from the well-worn, "So, what do you do?" Maybe it was the fresh air going to our heads, but this group, made up largely of Washington-area professionals, talked to each other about things other than work. For instance, the man with the 4-year-old in the bike seat said one sentence about his work -- he was a federal prosecutor working on the Iran-Contra affair -- and then the talk just sort of ambled into topics like insect sightings.

And I believe the days are longer out there. I feel like I did so much, but I took my sweet time all weekend.

The return trip, of course, was appropriately difficult. Nietzsche would have loved it. A series of small mechanical inconveniences culminated in a blowout on my friend's bike. A couple of guys in the group stopped and one of them hoisted her bike on his shoulder and coasted down the hill toward a store. The other told her to climb on his rack in back and hold on. They careened down to the store, and the guys worked for 45 minutes to get her and the bike rolling again.

If you ask her how the trip was, she will tell you this was the best part (and the food is a close second). For me, the best part is that AYH offers this trip again in the spring. BIKE TOURS

AMERICAN YOUTH HOSTELS -- "Three Covered Bridges Ride" is November 14-15. A 40-miler through Frederick County's farmland and gentle hills. Spend the night in charming Thurmont. $38 for members, $43 nonmembers, includes motel; bring your own lunch.

"Frostbite Ride" November 21-22 is a 60-miler from Washington to Bears Den Hostel in Bluemont, Virginia. This one is for the "adventurous, strong bicyclist." $28 members, $32 nonmembers.

AYH is also planning a bike maintenance training course this winter. For information about their programs call the Potomac Area Council at 783-4943.

POTOMAC PEDDLERS, this area's largest recreational bike club, will ask you to join up before coming along. Rides every weekend, short and long, near and far. Some longer tours are planned this fall for members. 363-TOUR.

OXON HILL BIKE & TRAIL CLUB plans a variety of weekend rides, year-round. Spokesman Bob McMaster says: "All you do is put on a couple more layers of clothes and go out and enjoy." They cancel rides if there is more than 50 percent chance of rain, or if the temperature is under 40 degrees, unless the riders decide to go ahead. You don't have to live in Oxon Hill, you just have to show up. Call McMaster at 839-4270 for a calendar of events.

RESTON BIKE CLUB organizes a variety of Saturday and Sunday rides all year round, no charge, open to all. Contact Dick or Janet Hayes at 860-0112.

GREATER WASHINGTON BICYCLE ATLAS -- Washington Area Bicyclist Association, a bicycle advocacy group, publishes this resource on bike routes throughout the region. Sold in most bike shops.