Could you please post thier license plates and some soft of identification, so that the police can track the culprits even after they have committed this disturbance?

Everyone, there are no license plates, nothing to identify the riders. These individuals simply show up and begin blasting through the streets. They are often joined by more adolescents riding those low motor bike-type vehicles on the sidewalks. I have seen them ride down Convent from the north in the direction of Morningside Park, perhaps they store their bikes up there somewhere.

When I saw the riders the other day, there was no crowd or anything else. Seems like the police could figure something out. Follow them ? Figure out where they hide ?

Someone is going to get hurt one of these days. One day, I was walking on the sidewalk with an elderly woman just behind me, at the corner of Morningside and 127th Street, when one of the sidewalk mini-bike riders blasted around the corner from the direction of St. Nicholas Terrace and nearly hit us both. He had a small child as a passenger ! Neither wore helmets. Right in the middle of the sidewalk.

I've heard that they store their bikes in the Bronx - I think the police know this too, but I am not sure on what grounds the police could make arrests while the bikes are not in use.

Every summer is the same problem. Only when the NYPD had those observation towers parked on the corner of Lenox and 112th St did the stunters stop riding by the area. But all that does is shift their "playground" to another part of Harlem. They run red lights, terrorize pedestrians, and violate every single law in the book. I hope they would crash and burn into a dumpster, so that sanitation can neatly take them away into some dump in New Jersey.

These people violate the laws and endanger the neighborhood.

Where is the NYPD?

If you can't catch them (which is indeed difficult for motorcycles and could lead to embarrassment), install cameras. Get lots of pictures of these guys. Then you can pick many of them up at your leisure. That's how England does it - http://www.bbc.co.uk/news/uk-england-london-14462271

We have the same problem further west (St. Nicholas Ave- Lenox Ave) in the 130s-- the noise is one thing but they run red lights and go very fast down side streets. Strange thing is there is a police station 3 blocks away and very often cops posted on every corner. I don't understand how this is a recurring problem given the oversight in the area.