While calling himself “an avid bike rider,” Mr. Liu expressed skepticism about the polling numbers on bikes. “It depends who’s doing the poll,” he said. “I don’t recall any opponents of bike lanes conducting any polls.”

Joseph J. Lhota, the former chairman of the Metropolitan Transportation Authority and a Republican candidate for mayor, also said he “could see” removing lanes that he deemed problematic. He noted that some bus drivers along the B63 route in Park Slope, Brooklyn, had complained about the perils of sharing space with bike riders.

In recent weeks, two of the Democratic front-runners in the race for mayor, Christine C. Quinn and Bill de Blasio, have faced criticism for their public comments on bikes.

In January, Ms. Quinn, the City Council speaker, told WNYC that she placed bike lanes “in the category of things you shouldn’t discuss at dinner parties,” alongside money, politics and religion.

“I think it’s a funny joke,” she said in an interview on Thursday, adding that now “it’ll be completely dead as material.”

Mr. de Blasio, the city’s public advocate, drew the ire of bicyclists last week after an interview with The Brooklyn Paper. Where bike lanes have worked, he said, “great, let’s keep them,” but “where they haven’t worked, let’s revise them or change them.” He also suggested that the city should consult “actual evidence, not biased evidence” in appraising the effectiveness of its lanes.

Paul Steely White, the executive director of Transportation Alternatives, a group that has gained considerable influence in the Bloomberg years, attributed the candidates’ positions on bikes to political “laziness.”