This wheely weird policy is getting a Bronx cheer.

Yankee Stadium bans bike helmets from all events, even though every other stadium in the New York City area allows them.

Bike buffs are going ballistic since their options are to either trash the head gear or stow it in lockers at a sports store across the street for $20.

“It’s totally ridiculous!” fumed Paul Steely White, executive director of pro-cyclist group Transportation Alternatives. “A sports team like the Yankees should be encouraging healthy, active transportation instead of discouraging it.

“It’s 2018. Biking is as mainstream a mode of transportation as driving or riding the train. It’s not polluting the air or taking up valuable parking space. The Yankees need to get with the times.”

The tired “YMCA” routine by the Yankee Stadium ground crew is still allowed, but no helmet of any kind – bike, motorcycle or even baseball – is permitted, according to the team’s website, which emphasizes, in bold letters, “There is no storage area for any items.”

The Stadium edict is a home run for S&A Sports, which does a booming business renting lockers for helmets at $20 apiece.

James Ratner, who bikes to work and always wears a helmet, paid the price Sept. 5 when he arrived at Yankee Stadium for a soccer match between the New York City FC and the New England Revolution.

“I wasn’t about to throw away a $75 helmet. Leaving it fastened to the nearest signpost or tree would also be tantamount to throwing it away,” Rather told Streetsblog, which first reported the story. “There’s no explanation for the policy. It’s just idiotic.”

At CitiField, cyclists can not only bring in their helmets, they can take them to their seat. At Barclays and Madison Square Garden, fans must check their head gear with guest services, but it’s free. MetLife Stadium football fans can check their helmets for free at a trailer located at each gate, but if you are going inside for a concert, you have to pay a $5 storage fee.

The Yankees did not comment.