Here is an old Japanese abacus Part #1 (abacus Part #2). I have fond memories of the abacus, or soroban in Japanese. When I first came to Japan for a brief stay back in the early 1980's I often visited an old mom & pop store and the proprietor would calculate the purchase using the abacus and then turn the abacus so that it was facing me to show me the total. Of course I had no idea how to read the abacus, let alone what the proprietor was saying as I spoke no Japanese at the time.
So what does this abacus have to do with vintage Japanese bicycles? On the back of the abacus is the infamous Hikari Dai Nippon Kikai Kogyo.
The following is exquisitely hand-carved 光自転車 大日本機械工業株式會社" （Hikari Jitensha, Dai Nippon Kikai Kogyo Kabushiki Gaisha). Any loyal fan of this blog will know that I have a great admiration for the Chinese characters or Kanji. To write these is an art all to itself, but to hand-carve these is another art altogether.
Craftsmen made these nearly all by hand (video) with each individual bead one-by-one hand finished. In today's fast paced, mass-produced, disposable society, I cannot help but feel that the abundance of cheap disposable goods has created a mindset whereby people no longer take care of things, feel a need to make them last, or, reuse things. Sad but true.