Calling Japanese indoor track cycling "wildly popular" is a bit of a stretch: it's one of only four sports in Japan that allow legal gambling, and it's generall

Calling Japanese indoor track cycling "wildly popular" is a bit of a stretch: it's one of only four sports in Japan that allow legal gambling, and it's generally considered the second least respectable, losing out only to powerboats (kyoutei). Not to put it too bluntly, but if you admit to being a keirin buff in Japan, you're likely to be taken to be either a compulsive gambler or a yakuza (who are widely rumored to control the business). The business is also in tough times, since the combination of Japan's aging population and tough economic times have slashed the sport's total take to 42% of what it was in 1992. (And that figure is from 2008, I have no doubt it's collapsed further since.)