NEW YORK — Jen Shao, the immigrant owner of a Chinatown souvenir shop, wasn't trying to make a political statement as she pedaled her bicycle through downtown Manhattan.
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.
Kevin Caplicki, whose group Visual Resistance 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 streets.
The rides — held partly for fun and partly to celebrate liberal, environmentalist ideals — began 10 years ago.
During last year's 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.
Cyclists in Brooklyn also have 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 such as not having a bell.
"For some reason, in the last year and a half the city has decided, 'That's enough' and now it's trying in every way possible to discourage cycling," said Bill DiPaola, executive director of the pro-bike group Time's Up.
A police spokesman did not respond to requests for an interview to discuss the department's interaction with cyclists.
Bike advocates enjoy a better relationship with the city's Department of Transportation, which in the past few years has done plenty to encourage cycling, including the creation of more than 100 miles of new bike lanes.
Those steps contributed to a growing number of riders citywide. An annual survey recorded 16,292 bicyclists pedaling past a series of checkpoints during a 12-hour period in 2005, compared to 12,757 five years earlier.
In the early 1980s, the same surveys found between 6,000 and 7,000 bike trips, said the transportation department's bike program coordinator, Andrew Vesselinovitch.
Transportation officials, at the request of cycling groups, recently pledged a study of all city bike fatalities from the past decade in an attempt to determine whether some or all could have been prevented. Vesselinovitch said planning for the study has already begun.
Bike advocates also have asked the city to more aggressively cite motorists for aggressive driving and commit to quicker implementation of a years-old master plan for more bike lanes and recreational pathways.
New York City should be an ideal place for cyclists with its wide, one-way streets, said Noah Budnick, projects director for the group Transportation Alternatives.
"New Yorkers love to ride, and there are a lot of characteristics of the city that make this a great place for riding," Budnick said.