Sgt. Chris Jahnke is one of seven Royal Oak (Mich.) PD officers involved in the department's fledgling bike patrol, established last summer. With the weather warming up, he hopes to spend about 16 hours a week in the saddle, cruising his town silently and swiftly on a specially-designed Trek police mountain bike.

"We go all over," said Jahnke, an avid cyclist who jumped at the chance to combine his hobby with his vocation. "Not just in the business district, either, but in the alleys and the neighborhoods."

Police Chief Ted Quisenberry said Royal Oak is a natural for officers on bikes, with its tightly knit downtown, its cafes and neighborhoods and its crowded streets and alleys.

Said Quisenberry, "The downtown businesses love seeing them there, and the guys out there riding love doing it. The program is doing everything it's supposed to be doing."

The bikes are one component of the department's growing emphasis on community policing--spending time with residents and helping reduce the intimidation factor that can accompany the uniform, badge and patrol car.

Each bike officer attends a weeklong class covering riding techniques, bicycle mechanics and even tactics for falling down.

Jahnke, fellow Royal Oak Sgt. Ken Nutter, and officers from other departments took a cycling class last week and embarked on a single-track, off-road adventure at Bald Mountain Recreation Area in Oakland Township.

The outing came after they spent much of the day practicing a more urban style of riding: power-slides, riding up and down stairs, speedy dismounts and the daunting task of carrying their 27-pound bikes through a tire-strewn obstacle course.

They even threw their machines over walls in a simulated pursuit of fleeing suspects. But it's OK--the $800 to $1,200 bikes are designed to take it.

"We beat them up pretty good, but they're tough," said Sgt. Mike Searing of the Oakland County Sheriff's Department, which has five deputies on bikes in Rochester Hills and another seven scattered throughout the Oakland County park system.

Other metro-area departments are expanding their bike programs, too. The City of Grosse Pointe, with its village shopping district and shaded neighborhoods, is one such department that finds bike officers invaluable.

"The merchants love it, and the citizens love it," said Deputy Director Dennis Van Dale of the Grosse Pointe Department of Public Safety.

Bad guys are less pleased.

"Those bikes can come zipping right up there, and you don't hear them or anything else," Van Dale said. "It's very surprising."