If you ride a bike and hear a word, Sekidobashi, you know what I mean.
We have a bicycle flea market twice a year, one in Spring and the other one in fall.
The third Saturday of April and September. We have some other markets but Sekidobashi is the only one I go for the most.
The earliest as far as I remember, it was around 2005 that I first attended.
At that time, it was mainly for rando and classic roadies. I remember there were always rando bikes lined up and people dressed in Euro classic and having chairs with bottle of wine. It was more like one day meetup event.
For the past 10 years or so, It has been a pure flea market and starts around 6 or 7 and ends before noon. You see the classic parts like old Campy or vintage mountain parts or even current components, and you name it.
Sekidobashi is a bridge on Tamagawa river. Tamagawa river has a cycling road along and Sekidobashi is a spot where all the cyclists in Southern Kanto area can gather by bikes.