Because a blanket statement saying that "[non-criminal] riding dirtbikes in a city is clearly antisocial behaviour that needs to end" isn't being disingenuous?

There is no such thing as "[non-criminal] dirt-bike riding in cities". Riding dirt-bikes in cities in the US is illegal. People who do it are breaking numerous traffic and road laws.

Asserting that doing this is anti-social is hardly disingenuous.

Even if it were legal, the noise pollution alone would make it unquestionably anti-social as far as I am concerned. I'd rather have tractor trailers using jake brakes in my neighborhood, that's how unreasonably loud these bikes are.

(In case there is a misunderstanding here: dirt-bikes are stripped down light-weight motorcycles meant for off-road use only. They are not street legal. Similar I believe to a motocross bike.)

I guess my real problem was you calling the author disingenuous, when the author specifically identified 'riding dirt bikes on the streets in the suburbs' and you explained this away to actually being 'riding dirt bikes in paddocks in rural areas'. The author's point is that this was the same crime, but suburban whites were not pursued for it - and you're saying "it's not the same crime, the whites were riding around on farms, not streets".

This bit of cultural knowledge is important.

I was thinking of dirtbikes as their UK equivalent. Here, youth ride scooters / mopeds and some of them are styled as like dirtbikes. And there are probably road legal dirt bikes of more than 125 cc.

The gang context is also really important.