Certainly, the bikes from the French constructeurs were among the lightest anywhere. But while the weights from the technical trials are well-documented and true, these weren't bikes you could buy. Every component was modified. (See the Rebour drawings in Vintage Bicycle Quarterly Vol. 2, No. 1).
On the other hand, the catalogue weights from Singer and others were a bit optimistic!
For our book "The Golden Age of Handbuilt Bicycles," we weighed most of the bikes we photographed. (The weights are listed together with serial numbers and tire sizes in the back of the book.)
The Rene Herse from the 1947 technical trials (one of about 5 or 6 ever built) really was close to its advertised weight of 7 kg (15.4 lbs.) once you deducted the tires and inner tubes (see also the article on this bike in Vintage Bicycle Quarterly Vol. 4, No. 1). The remaining difference was due to some parts having been replaced with "stock" items. Pretty amazing for a bike with 8 speeds, a rack, 35 mm clincher tires, fenders and lights.
But among the customer bikes, the lightest are about 9.5 kg (21 lbs. for a Barra and a Marcadier with aluminum frames), and 10.5 kg (23.0 lbs) for a fully equipped 1947 Singer with gears, lights, fenders, 2 racks and fat 650B tires. Still lighter than anything comparable you can buy today, but not as light as the catalogue promised...
Most cyclotouring bikes in our book weighed about 10.5-11.5 kg (23.0-25.3 lbs.), again with fat tires, gears, racks, fenders, lights. For comparison, the lightest fully equipped bike VBQ has tested, the Weigle Randonneur, weighed 10.7 kg (23.6 lbs).
Jan Heine Editor/Publisher Vintage Bicycle Quarterly c/o Il Vecchio Bicycles 140 Lakeside Ave, Ste. C Seattle WA 98122 http://www.vintagebicyclepress.com
>YES! Exactly as Mike Kone remarked, the 30-40s were the heyday for
>testing the limits of bicycle weightlessness. And the French
>Constructeurs were the masters of pushing the limits.
>
>Here are just a few random quotes from a 1998 paper on Alex Singer
>written by Raymond Henry:
>
>"In 1939, Alex took part in the Gran Prix du Duralumin... which took
>place in the Vosges mountains in eastern France over a distance of 550
>km.... Alex Singer entered four tandems, including one weighing just
>under 13 kg (28.66 lbs), a record for the time...."
>
>"...1946 at Colmar in Alsace... a Singer bicycle won the camping bicycle
>series and another the prototype series. The latter, without the tires,
>weighed just under 6.9 kg (15.1 lbs)...."
>
>In 1950 there was mention of his proposed standard catalog production
>models including:
>
>The PERFORMANCE model:
>
>"...weight [without tires] for a 55 cm frame: 7.9 kg (17.4 lbs)... 700c
>wheels with Bell wing nuts... alloy mounted [alloy railed] Ideale
>leather saddle... dynamo headlight with red rear light..."
>
>An illustration shows that model also included a 5-spd freewheel, front
>luggage rack, and full rear and front fenders with mudflap, front and
>rear cantilever brakeset, toeclips and straps....
>
>That model had only a single chainring. However, it could also be
>ordered with some of Reynolds heavier gauge tubing, and with a
>Specialtes TA triple crankset (to give 15 speeds), a SKF sealed bearing
>bottom bracket, remote control (ie: cable actuated) dynamo... and
>naturally all of the above components and accessories.
>
>Weight would then be increased to 8.9 kg (19.6 lbs.). ~ Still not bad
>for a fully pimped-out standard production model bike.
>
>Yes, the bike of my dreams may already have been built before I'd even
>exited the womb - 56 years ago.
>
>Cheers!
>Bob Hanson,
>Albuquerque, NM
>
>-----------------------
>
>Mike Kone wrote:
>
>Figure that for mid-to-late 1930's state of the art for lightweight was
>in the 15 to 18 pound range. Few bikes made it that light, but some
>did.
>
>I recently picked up a 1941 or so Narcisse - weighs a smidge over 18lbs
>- and we aren't talking fix gear here.
>
>Note that it is the French who could get the weights down usually. By
>mid 30's everything was alloy including frames in some cases. Narrow
>tubular rims existed, and super light tubular tires were
>available. Most bikes until the present day were really rather heavy
>compared to what they could have been. And of course, weight only
>matters for acceleration and climbing - it reality, weight really
>doesn't matter much at all - at least if you go fast its relatively
>unimportant. Now wind resistance...
>
>Mike Kone in Boulder CO
>
>
>--------------
>
>From: Simon PJ <simonpj(AT)mac.com>
>
>Having just passed some idle hours wondering about the weight of my
>bikes and finally figuring out that I could weigh them by holding them
>whilst I stood on the scales, I would be interested to know what really
>was 'lightweight' for a racing bicycle in the 40's, 50's, 60's and 70's.
>
>I was surprised - but probably shouldn't have been - that my most recent
>bike, an OT Pinarello Vuelta from '98 wearing a mix of Campagnolo
>C-Record and Chorus from the 80's and 90's was the heaviest at a little
>over 23 pounds - whereas a 1948 Holdsworth Cyclone Deluxe and a 1954
>Bates, admittedly both with fixed gear, came in at just under 20 pounds,
>even with their full complement of period steel cranks, etc.
>
>So, what weights were racing cyclists trying, and managing, to get their
>bikes down to - in the on-topic decades of the last century?
>
>Wyndham,
>Girton, UK