Police Commissioner Bill Bratton sent a clear message Tuesday to “the nitwits and the knuckleheads” who ride illegal dirt bikes and ATVs in the city: the NYPD will crush your bikes. Literally.

Holding a black and white checkered flag, Bratton watched as a pair of bulldozers pulverized dozens of bikes in what he said is an effort to make space for even more that will be seized.

“I think we are clearly sending a message that we will crush them, we have crushed them, and we will continue to crush them as we gather more of them,” Bratton said, standing at one of the city’s auto pounds in Red Hook. He added: “They’re just a plague on the city and you see a tremendous amount of calls about these things.”

Last year, Bratton said five people died in ATV or off-road vehicle-related incidents. There have been no deaths so far this year.

Chief of Patrol Carlos Gomez said there have been 679 of these types of bikes confiscated so far this year, a 95% increase over last year. The department started their push to seize these bikes earlier this year, he said, “to set the tone.”

This past weekend, he said the NYPD confiscated 39 ATVs, motorcycles and dirt bikes, 21 of which were in the Bronx and Manhattan.

“This behavior endangers motorists, endangers bicyclists, endangers pedestrians. But it also endangers themselves, the riders of these vehicles,” he said. “And for those who witness these events, it could be very intimidating.”

Gomez said while the department sees more ridership as the weather warms up, the NYPD is ramping up their efforts to catch what he calls the “motorized wildling.”

The crushed bikes — there are nearly 900 of them at the pound — will be sold for scrap metal at a couple cents a pound.

“I hope we make a few bucks with it,” Bratton said. “You’re not going to get rich.”