The one nice thing about being in a pandemic, is that you do get time alone to catch up on things ! 🙃 I’ve actually been quite busy since the start of the year with a load of things, including researching some additions to the Old Japanese Bike Compendium (just check my website at this link). In this, I have been able to identify another handful of former manufacturers, one of which is a pre-WWII make called the SSD (see this link). These 
machines were made between 1930 and 1934 by the Shishido brothers in Hiroshima, and were 250cc and 530cc side valve singles patterned after British Triumph machines of that time period. Recall that prior to roughly 1930, British, American and European machines were the predominate makes available in Japan, but in the build up to WWII, import tariffs, the collapse in the exchange value of the yen, and in general the global effects of the Great Depression effectively blocked the sales of foreign makes, and so domestic manufacturers started to appear in larger numbers. SSD folded in 1934/35 as financing dried up due to the government focusing on the war effort, and the assets and engineering moved to Dat Motor (now Nissan) and Toyo Kogyo (now Mazda) who were both heavily subsidised in the Japanese government’s armament programmes.
As an interesting historical footnote, to circumvent both the import tariffs and the effects of the depression, Harley-Davidson actually sold a complete factory, together with all the design information (what is now known as ‘intellectual property”) to a Japanese subsidiary who then made machines for the Japanese military under the Rikuo brand name. As well, the H-D engine design was used (and improved !) for other makes, including the Kurogane. As has been offered by others, H-D is in some ways actually responsible for the success of the post-war Japanese motor-vehicle industry ! 😲 Just check the ‘Rikuo’ and ‘Kurogane’ sections on my website for more details ! 😉
In addition to working on my 1975 GT380 in the shop, the other thing I’ve been doing as adding yet more manuals to my website (at this link). The most recent additions this week include:
- the F50 parts manual
- the M31 parts manual
- the T125 parts manual
- the T20 parts manual
- and both the T200 shop and T200 parts manuals
For anyone interested in these things, that represents roughly 6000 page images of Suzuki manuals that I have made available online to restorers during the past 10 or 12 years, plus all of the other material on the website (north of some 20,000 pages of material in total). And “yes” : I do make sure that I back up regularly ! 😉
Enjoy ! 😎