The immigrant owner of a Chinatown souvenir shop, Jen Shao, wasn’t trying to make a political statement as she pedaled her bicycle through downtown Manhattan two months ago.

The 65-year-old woman biked, her family told reporters, because she found it easier than walking.

But her September death beneath the wheels of a tour bus was one of an increased number of biking fatalities this year, adding a melancholy edge to long-running tensions over the presence of bicycles on the city’s crowded streets.

With a month left in the year, police records show 21 cyclists have died in traffic accidents in New York, up from 15 in all of 2004.

The number may just be a statistical anomaly, transportation officials said. Between 2000 and 2004, traffic accidents killed 82 cyclists in the city, according to the National Highway Traffic Safety Administration – an average of about 16 deaths per year.

This year’s small spike has further angered a riding community already upset by what they perceive as an unfriendly view of bikers among some drivers and city officials.

Within weeks of Shao’s death, a group of artists installed a tribute at the spot where she fell; a bicycle, painted white like a ghost, and a plaque inscribed with her name.

The head of the group Visual Resistance, Kevin Caplicki, has created six “ghost bikes” this year to memorialize fallen cyclists, said they want people to rethink the American notion of the car as king.

“This form of transportation and the people who use it are really invisible,” he said of the city’s bicyclists.

The memorials are the work of some of the same cycling enthusiasts behind “Critical Mass,” a once-a-month nighttime group bike ride through the city’s canyon-like streets.

The rides – held partly for fun, and partly to celebrate liberal, environmentalist ideals – began 10 years ago. But the city’s perception of it changed dramatically last year during the Republican National Convention.

Thousands of political activists temporarily swelled the ranks of the ride, and police responded with a crackdown. Hundreds of riders were arrested on charges of parading without a permit.

The rides have since shrunk to a few hundred bikes or less, but police action has continued. Dozens of arrests are now routine at the gatherings.

City officials also sued to stop the rides altogether, maintaining they are illegal without a permit. The cyclists won some early rounds in the litigation, but the case is still pending.

Lately, bicycle groups have complained that the crackdown was spreading.

Cyclists in Brooklyn griped that their bikes were confiscated en masse from spots near a subway station, allegedly for violating sidewalk clutter laws. And members of the New York Bike Messenger Association say police have conducted ticketing blitzes this fall, stopping and citing riders for minor infractions like not having a bell.