More than 100 metropolitan area police officers, and some from as far away as Florida, gathered on a rainy parking lot in the Groveton section of southeastern Fairfax County yesterday for a daylong test of their motorcycle-riding skills.

Officially, this was the Mid-Atlantic Police Motorcycle Rodeo. But there wasn't any purpose to it except for friendly competition and a shared love of regulation police bikes -- Kawasaki 1000s and various large Harley-Davidsons.

The object was to steer a motorcycle through a course defined by about 1,000 orange traffic cones that had been set up on a straightaway at Beacon Mall, behind the Baskin-Robbins store and a branch of Household Finance.

There were several categories of competition, including handling ability at fast and slow speeds.

Most of the spectators who stood behind yellow crime-scene tape, munching doughnuts and drinking coffee, were other police officers.

In fact, Fairfax County probably hasn't seen as many police assembled in one spot since last year's Lorton Reformatory disturbance.

The officers wore helmets and polished boots and were distinguishable by the colors they sported: blue jackets for Fairfax officers, tan for the Maryland state police, and other colors for other departments.

Also taking part in the competition were members of the Virginia State Police.

"We've been practicing for several months to get ready for this," said Fairfax County Police Sgt. Ed Janik.

Another Fairfax officer, A.J. Neville, was one of eight competitors who aced the first part of the competition. But Neville and his 1986 Harley were eliminated during the speed run.

"This is great, though," he said. "A lot of good police departments here, and a lot of good riders."

"A new experience for me," said Maryland state trooper Frank Wastler. "It's my first time here. A new adventure."

Wastler said he usually can be found patrolling the Eastern Shore or the Chesapeake Bay Bridge.

Also representing the Eastern Shore was Maryland trooper William Updegraff. "I did real good for the first time," he said.

Larry Abrams, Rich Martin and Mitch VanSant were among eight police officers who rode to the event from Fort Lauderdale, Fla. All sported tans, and none was thrilled with yesterday's chilly weather.

"We don't get this until February," one of them said.

Officer Mel Brown of Prince George's County rode smoothly through the course as onlookers offered such comments as "Smooth ride" and "He's silk."

Afterward, Brown took a moment to recall the man who initiated the annual motorcycle rodeo event, a fellow Prince George's officer named A.D. Johnson, who was killed in the line of duty in 1982 during a traffic stop on the Capital Beltway.

"He started it because he wanted to increase the camaraderie and people's riding skills," Brown said. "And that's what's happening here today."

Dave Dailey of Fairfax County finished first in the individual competition category and won this year's A.D. Johnson Trophy.

In the overall team competition, Fairfax came in first, followed by the D.C. police department and the Baltimore City force. The winner in the team slow ride category was a four-officer squad from Fort Lauderdale.