SAN FRANCISCO -- New York is wooing cyclists with chartreuse bike lanes. Chicago is spending nearly $1 million for double-decker bicycle parking.

San Francisco can't even install new bike racks.

Blame Rob Anderson. At a time when most other cities are encouraging biking as green transport, the 65-year-old local gadfly has stymied cycling-support efforts here by arguing that urban bicycle boosting could actually be bad for the environment. That's put the brakes on everything from new bike lanes to bike racks while the city works on an environmental-impact report.

Cyclists say the irony is killing them -- literally. At least four bikers have died and hundreds more have been injured in San Francisco since mid-2006, when Mr. Anderson helped convince a judge to halt implementation of a massive pro-bike plan.(It's unclear whether the plan's execution could have prevented the accidents.) In the past year, bike advocates have demonstrated outside City Hall, pushed the city to challenge the plan's freeze in court and proposed putting the whole mess to local voters. Nothing worked.

"We're the ones keeping emissions from the air!" shouted Leah Shahum, executive director of the 10,000-strong San Francisco Bicycle Coalition, at a July 21 protest.