"NOTE: A Gitane collector submitted specs for the 70s vintage TdFs that are definitely pretty stretched out: 72.5 degree parallel, 5.5cm of rake and 45cm stays.
-Dave Mann, Boston, MA"
"Stretched out"?!
One of the joys of taking this stuff out on the road on a regular basis is explaining that, yes, this really is a RACING BIKE of its era and yes you really can put a fist between the seat tube and the rear tyre and still still won lots of real roadraces on such things. Honest. But why I am explaining the geometry of my proper steel racing machine to a guy riding a "racing bike" with a girl's sloping top tube that looks four times too small for him anyway?
72 parallel angles on a racing bike was the standard in the 1960s I think, certainly the PX-10 had these measurements from late 1950s through to about 1973. And I think 73 parallel was pretty much the standard for Italian machines of late 60s-mid 70s. There was recently some discussion if "Gran Criterium" was applicable to the Masi of the same name and by modern standards, certainly not and even maybe not by contemporary ones of the day. My '71 GC is a creampuff compared to even my '74 Colnago in ride and my '75 Gios all the more nimble and "racy".
Contemporary British machines like the Carlton Giro d'Italia/Raleigh Professional were, if anything, more severe in geometry than the Continental stage racing bikes with higher bottom brackets and reflecting British preferences for timetrialling perhaps. Holdsworth Professionals started out as 73 parallel in 1971 went to 74 c. 1973-74 and even 75 parallel a year later which was found to be too twitchy and they went back to 74 but all still way stiffer than most Continental makes of the time. Falcon San Remo's were 73 parallel from their inception, I think, which made them very stiff compared to their 1960s contemporaries and with less fork rake than many British makes but still with those long 17 and some chainstays.
Fork rakes seem to be LONG on French and British machines and shorter on Italian ones of the same era. More than angles, I think this really distinguishes the handling and one of the reasons Merckx was said to have both thoroughly disliked riding PX-10s and didn't master descending until he got Italian iron under him. And top tubes, likewise, longer on French and British frames. Ideally, I'd prefer to climb Mt. Ventoux on my PX-10 and descend it on my Gios or Colnago and time trial on a Raleigh/Carlton Pro.
I don't collect pre-war machines, but suspect the average was probably 70 on French ones, maybe 71 on Italian. But immediate post-war doesn't look much different and Coppi looked like a sparrow stretched on the rack on those long top tube Bianchis of the day.
Peter Kohler
Washington DC USA