Not really sure of the true period of this catalogue as there is no date on it but the general style and design would indicate early 1920. Humber introduced the 500 and 600cc flat twin motorcycles after returning to production at the end of WW1. Pre war saw Humber design a flat 3 cylinder 750cc engine, with 1 cylinder forward and 2 cylinders to the rear, indicating that they were thinking outside the box when it came to all things engine. The Humber 600cc engine would yet be another interesting creation with external flywheel, detachable valve pockets, gear driven oil pump, and Claudel-Hobson Type M.I.A carburettor.
The 3 models in this booklet are the Standard Flat Twin, the Sidecar Combination and the Sports Model with flat bars.
Whether or not we may own such a machine just looking at the illustrations of the mechanicals would make one admire the ingenuity that existed in early motorcycle design.
Click on the front cover below to see the complete 21 page catalogue.
It is a 7M PDF so you will need Adobe Acrobat Reader to view it.