The only current rim (リム＝re-mu) used in keirin track racing in Japan is the 16B Gold, manufactured by Araya Kogyo in Osaka, Japan. This, like any previous NJS-approved rim is a 36 hole tubular 700c size rim. Professional keirin racers glue-on their tires, but for the street or even amateur track use we often use Miyata Tubular Tape instead.
The Araya 16B Gold is a super-low profile polished rim 11.9mm in height. Older rims had a very thin 0.9mm thin side wall but due to safety concerns (remember that multi-rider crashes are daily routine in Japanese keirin racing) the side walls are now 1.1mm thick.
Up until Feb 2000 Araya had a ‘RED’ and ‘GOLD’ model, Red being the slightly stiffer and heavier rim, and the Gold being a bit lighter.
Keirin race-bike wheel lacing is done in the unusual ‘4 Cross’ pattern, known in Japan as ‘happon’.
From 1983 Araya offered a titanium version known as the Tita-Ace Gold, which was .4mm thick all around. The rim was quite expensive, and exotic, but was discontinued in about 1994. The NJS approval expired in 2010.
Nice examples are hard to find in Japan and very expensive. Most still out there have been raced and are dented and/or warped.
Another rare rim which was around mainly in the 1970s and 1980s was the Ukai (pronounced oo-ka-i) 16B rim. From 1969 to 1976 they were made with an ultra-thin 0.8mm wall. Early rims had no eyelets and were built with washers between the nipple and rim. Eyelets were included from 1976 and the NJS approval expired in 2001 although nobody was using them by then. Araya had already been using a far superior joining method on their 16B rims as well as a nicer polished finish. They are now quite hard to find especially in good usable condition.