I do not know much about racers, but tourists did use both clinchers and tubulars in the 1930s. Aluminum rims became popular by mid-decade - see these early Mavics on this Reyhand
http://www.vintagebicyclepress.com/
The size was 584 mm (650B) for most French cyclotouring bikes that I have encountered from that era, so modern tires fit. Finding 42 mm wide 650B tubular tires must be close to impossible today, yet I know of a few bikes that used them originally.
Somebody else can comment on the racing bikes... but if I recall correctly, by the late 1930s, 700C tubulars were a popular choice.
Jan Heine Editor Bicycle Quarterly 140 Lakeside Ave #C Seattle WA 98122 http://www.bikequarterly.com
At 12:23 PM -0400 7/28/08, pikemanstacey@aol.com wrote:
>Hi,
>
>I need some information on 1930's rims. What size rims did Italian
>and french riders use in the 1930's? I've heard of the Fiamme rims,
>but not the size, was it 622mm (700c) or something else? And was it
>exclusively sprints, or did they use clinchers? Or was it a distinct
>racer/tourist divide as it is/was in the UK? Any information would
>be greatly received.
>
>Regards
>
>David Robert Stacey
>
>County Durham
>
>UK
>
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