Urban dirt biking has surged in the Bay Area over the last five years. The phenomenon has been linked to Baltimore, where inner city dirt bikers were the subject of the 2013 documentary “12 O’Clock Boys.”

The Bay Area riders aren’t to be confused with another motorcycle subculture that is built around supermoto bikes, nimble two-wheelers that can navigate both dirt and pavement.

Supermotos look similar to dirt bikes, and their owners also go on group rides around the Bay Area.

A few differences:

— The dirt bikers are more associated with acrobatics, known as stunting, whereas supermoto was born out of racing.

— Unlike many of the dirt bikes, the supermotos are usually street legal.

— Supermoto riders are seen as less brazen.

“Generally, they don’t break the law,” said Gabriel Ets-Hokin, a Bay Area-based motorcycle journalist. “It’s a very different thing.”

Still, the distinctions may be lost on motorists who find any swarm of motorcycles disconcerting.

Supermoto riders are mostly drawn to “carving the hills,” said Liza Miller, host of the Motorcycles and Misfits podcast in Santa Cruz. But occasionally, they speed, blow through red lights or jump railroad tracks.

“I can tell you,” she added, when you get on a supermoto, “you get that feeling like you just want to do bad things.”