“There was a perception that the bike share system was not for us, that it was part of gentrification,” said Tracey Capers, an executive vice president at the nonprofit Bedford Stuyvesant Restoration Corporation. “We wanted to change the conversation to show people it was for them.”

Despite a similar campaign to attract women, female riders still account for less than a third of regular Citi Bike users. Women often cite concerns over traffic safety and the inconvenience of having to carry a helmet or change clothes after a ride. The share of female members grew slightly this year to 32.7 percent, up from 31.5 percent in 2015, according to Citi Bike. The company said it did not have comparable figures for race or income because it does not ask members for such information.

Many New Yorkers across different races, incomes and genders are concerned about riding safely on harrowing city streets. Though traffic crashes remain a persistent problem, no Citi Bike riders have died in an accident since the system started in 2013. But overall cyclist deaths in the city are up this year. There were 17 deaths so far in 2016, compared with 14 during the same period last year, city officials said.

Some bike riders believe Citi Bikes are safer because they are slower than personal bikes, or their bright blue hue is more noticeable to drivers. But safety advocates say there is another reason: the current Citi Bike zones have good access to bike lanes. They have called for more bike lanes as part of Mr. de Blasio’s Vision Zero plan to reduce traffic fatalities.

Using Citi Bike offers many benefits, advocates say: It is an easy way to exercise, a more affordable travel option than using subways, buses or taxis, and provides flexibility for moving between areas that are not connected by subway lines.

Still, even in neighborhoods that have Citi Bike, many people are reluctant to try it. On a recent sunny afternoon, a bike station outside the Marcy Houses in Bedford-Stuyvesant was filled with 23 bikes; not a single slot was empty.

“I don’t use it — I don’t have a credit card,” Andrew O’Keefe said as he stood near the station.

Mr. O’Keefe, 28, who works in construction, said he would consider using Citi Bike if the machines accepted cash — a common concern for those living paycheck to paycheck or who have poor credit.