Other Japanese Manufacturers
As readers may have noticed, this site is primarily a Suzuki resource site, but obviously Suzuki was not the only 'Old Japanese Bike' manufacturer in Japan. It may surprise people to know that motorcycles were made in Japan prior to WWI and that by the early to late 1950's there were roughly 200 companies all fiercely competing for market share in the Japanese domestic market, which rapidly collapsed down to the four main players (Honda, Kawasaki, Suzuki and Yamaha) still in business today.
I have drawn from several sources for this work, but one individual I'd like to specifically mention is Mike Walker in the UK who provided some initial scans of material, together with suggestions for where to continue looking. Print sources that I used as reference include 'Japan's Motorcycle Wars" written by Jeffery W. Alexander, the "Encyclopedia of Motorcycles" edited by Erwin Tragatsch, "Classic Japanese Motorcycle Guide" by Rod Ker and "A Century of Japanese Motorcycles" by Didier Ganneau and Francois-Marie Dumas. As well I have referenced a discussion thread on the gt-rider.com site posted in 2009 by a contributor named 'HIKO', and the Japanese language version of Wikipedia covering defunct domestic motorcycle manufacturers located at this link. I also spent quite a bit of time sorting through a Japanese language site called 'Motorcycle Forum Central' ( モーターサイクルフォーラム中部 ) which is found at this link and offers a wealth of information, and there is a Facebook group focused on older Japanese machines as well (just search for "Japanese Motorcycles 1909-1959"). And of course there is the 'net' in general, although sifting the fact from the fiction/opinion does take time.
My plan then is to fill in information on the various manufacturers with a focus on those companies no longer in business. In the case of Honda, Yamaha and later Kawasaki data (post early 1960's), there are already loads of sources out there so I see no need to duplicate what others have already done.
To frame the story a bit, the two images below are interesting as they show the early genesis of the industry in Japan prior to WWII and then its evolution post WWII from the remains of the Japanese armanents industry. These two charts are both from "Japan's Motorcycle Wars" by Jeffery W. Thompson which is not an easy read, but which does offer a wealth of information and useful context.
It has been asserted by many sources that early Japanese manufacturers generally just copied or stole American and European (which includes of course the UK) designs, and certainly in the early days that was sometimes true. That does ignore the fact that in early engine and bicycle development 'copying' was done by just about everyone in all countries, so I'm not sure how important that point really is. I think what is true is that in the brutally competitive domestic market in Japan following WWII, those manufacturers that ultimately survived in Japan did so because they were the fittest. Having survived that Darwinian process in the home market, they were well positioned to eventually decimate the motorcycle manufacturing industry in the rest of the world.
Ian R. Sandy December 1, 2018