Identifying Douglas motorcycles- Part 3: The Postwar Models

[Doug]

Identifying old Douglas motorcycles
Part 3: The Postwar Models (excluding Vespa scooter) 

Owners and folks finding an old Douglas motorcycle (or bits and pieces of one) often need to know how they may be able to identify the year and model.  What follows is a personal attempt to provide a guide to the codes and numbers that the factory put on the main parts of Douglas machines -specifically, frames, engines and gearboxes.  Supplemented with a description of salient features that in the addition/absence of the codes, might help also to identify a specific year, or indicate a mixture of parts.  Particularly in the case of the postwar models, many parts and major assemblies are interchangeable.  Also in the 1960-1970 the postwar models were just old used motorcycles and quite cheap at that, so no one thought twice about hacking one about and building up one from a mixture of available pieces from various years and models. 

All the post-war production models were all 350cc horizontally-opposed transverse OHV twins. Some larger capacity prototypes were also tried out, but never went into production. The standard range was supplemented by 'Sports' models, a Competition model, and the Clubman's/Racing 'Plus' models. 

The link below will take you to a page with additional information and tables to identify the various models and years.  These pages will be updated from time to time as additional information comes to light.  So note the version number near the top, and compare it to any copies you might have saved or printed.  There are also hyperlinks back to this post, and to Part 1 and Part 2 covering the rest of the Douglas range. 

The information in these tables has been collected from various sources: factory records, registers of extant machines, Douglas publications, articles in the London Douglas Motor Cycle Club magazine the New ConRod, and personal knowledge.  While every effort has been made to provide the most accurate information available, the information provide above is offered as a guide only.  It is not recognized as official dating data by any licensing authority.  The numbers and codes shown in these files are what appear to me to be representative of most of the machines registered as that model.  You may find them useful as indicators, but for final confirmation please do check with the experts in the London Douglas Motor Cycle Club (LDMCC), as I cannot accept any responsibility for any errors that may occur through the use of this information for identifying something that you find. 

If you have any additional information, corrections, or constructive criticism, the author would be pleased to hear from you. Please address your comments by e-mail or Personal Message using the link appropriate to your choice in the left block beneath the avatar. Alternatively, to make public comment  please use the Back button on your browser to return to the Topic Index and post a new topic by selecting the Start New Topic link at the top of the page.

If you have questions about a particular part or bike you are trying to identify, please use the Back button on your browser to return to the Topic Index and post a new topic by selecting the Start New Topic link at the top of the page. 

-Doug K.

Copyright Doug Cross, Doug Kephart, April 2005

The Link:
Part 3: The Postwar Models (excluding Vespa scooter)

[Doug]

Please note that the Identification of Douglas Models above has been updated. Correspondingly, the version number below the title in the linked "Part 3" has been indexed. If you have a copy of the tables, you may wish to replace it. You may notice a skip in the version numbers; they are indexed based on working copies which might go through several iterations before being released. The latest and greatest is what you see posted. Enjoy!

-Doug 

[Doug]

The table has not been updated, but it is now known that the 1938 Aero 600 model used a 6/Q prefix for the transmission. Same as the 6/Q prefix that it used for the engine and frame.

-Doug