Originally Posted by
sd5782
We are lucky to have generous tire clearance on nice sporty frames from the past. Why was it the case for so long? It seemed on sporty type bikes at least in the 60s, 70s, and early 80s that tubular tires and skinny clinchers were used. Did the makers use bottom brackets and head and seat lugs across a larger product line? I don’t really recall these type of bikes with larger tires in the lesser models.
Was it a case of that being the way it had always been done? It would seem that the castings would have needed to be changed for the angles for the more sporty frames. Were these sporty bikes such a small niche that larger changes didn’t make sense? Perhaps it takes a long time to change things, but skinny tires were around for a long time before clearances tighten up drastically in the later 80s. Either way, it is something that many of us appreciate when looking at these older bikes to resurrect
.
Every once in a while someone comes up with a great basic question like this. The most likely explanation is that in the first half of the 20th century, most European roads (other than those in good-sized towns and cities) were unpaved dirt or gravel, so the standard (tubular) tires used with drop-bar bikes were wide. Those roads were gradually improved over the decades, but there was no compelling reason for frame builders to cut down on clearances until it became fashionable to do so.
Also, many models of European racing bikes sold in the '60s and early '70s were shipped with fenders, so the frames would have needed a good amount of clearance. (When I think of all the pairs of color-coordinated Atala, Frejus, and Legnano fenders we threw away in the bike shop I worked in during the '70s, it makes me want to cry.)