More than 7,000 bikes will flood city streets in the much-anticipated bike share program starting next month – but some say the spokes are missing a crucial accessory.

City Comptroller John Liu said today that the program has one glaring hole – the lack of helmets.

“In the rush to place 10,000 bicycles on our streets, City Hall may have pedaled past safety measures,” Liu said.

Helmets are not legally required for adults in New York State, and the city Department of Transportation will not require them for the bike share.

DOT spokesman Seth Solomonow told Metro that they encourage every rider to wear a helmet, and are planning giveaways and helmet discounts for bike share members. He noted that the DOT has given away more than 50,000 free helmets since 2006.

DOT Commissioner Janette Sadik-Khan said in a statement yesterday that as biking numbers have quadrupled, crash numbers have remained stable.

But Liu, who said he supports the bike share, noted that 97 percent of cyclists killed were not wearing helmets.

Dr. Jamshid Ghajar, head of the Brain Trauma Foundation and at Liu’s press conference, said bike helmets can reduce the risk of head injury by 85 percent.

“Helmets save lives, even when you are going slowly on your bike,” he said.

Nancy Gruskin started a bike-safety foundation after her husband Stuart was killed by a wrong-way delivery biker in Midtown in 2009. Standing alongside Liu, she said she couldn’t believe that the 10,000 new bikes set up by the end of the year wouldn’t come with head protection.

“I think it’s absolutely common sense to understand that someone on a bicycle on a crowded Manhattan street, with cars around and trucks around, that they’re going to be having their life in their hands if they don’t have a helmet on,” she said.

Gruskin’s husband died from head trauma after he was hit stepping off a curb.

“I am a walking example of if you fall one way, you’re OK, if you fall another way, you’re not OK,” she said.

Stephen Arthur, 44, said a helmet very likely saved his life when someone threw a brick at his head in August while he cycled under a Brooklyn overpass.

“Who knows what would have happened, but it’s possible I would have died,” he said.

Although he himself wears a helmet everywhere, he said, “I don’t like to tell anyone what to do.”

Safety suggestions

Bike-share users may be less likely to wear helmets — a Georgetown University study released this month about the Washington, D.C., program found that 33 percent of bike-share commuters wore helmets, compared to 70 percent of commuters biking on their private cycle.

To encourage more helmet use, Liu suggested that the city create a vending machine to dispense helmets, an idea from MIT students called HelmetHub.

Stephen Arthur said he worried that requiring helmets would make cycling less safe — by requiring helmets, fewer cyclists might ride, he said. And more bikers in the city might make it safer for everyone, he said, because that means more pedestrians and cars are used to navigating around and paying attention to cyclists.

Caroline Samponaro at transit-advocacy group Transportation Alternatives, said the city should focus on preventing crashes by stopping dangerous drivers. “A plan that forces New Yorkers to wear helmets won’t prevent the crashes that put them at risk in the first place,” she said. “To protect people from gun violence, we don’t force them to wear bulletproof vests — we correctly focus on stopping gun violence in the first place.”