I wouldn't say it's the worst part, but it's definitely a common disturbance in japan that these idiots called bousouzoku ride around in quiet neighborhoods with their mufflers modified that they are screaming as loud or exceeding 110 but sometimes even 110 db.

And they really look like idiots when for example I easily pass them on my road bike in the Shonan area on road 134 because the roads are too narrow there to pass any cars even on a motorbike (mostly just the roadbikes are able to pass there), and they are just inching forward in the traffic with 2 km/h while revving their engines. Absolute losers.

And the longer summer definitely encourages these idiots to be a nuisance longer