Tom wrote:
"I am wondering if those who know can shed some light on when the change from 27" wheels to 700C wheels came about, was it gradual or abrupt, what triggered the change, how to tell on a frame just what wheels are needed and if what you are seeing is instead a calling for a different reach brake than the ones one has on hand, etc.? I know that I have changed them on bikes for reasons of tire availability, what wheels I had on hand, etc. Other than the greater tire availability of 700C wheels, I sure can't see any advantage to them and wonder how we ever got started in adding one more complication to the bicycling mix."
700C clinchers have been around for over 80 years and during this period has always been the predominant continental European wheel size on racing and sports bikes. This holds true whether in France or elsewhere on the European continent. To answer Jerry's question, the 650B size was as good as never used for racing. They were generally made in "ballon" and "demi-ballon" sizes; both which are considerably wider than the average 700C tire. The 650B was reserved for touring, sports-touring and city bikes. 27" wheels were an anomaly reserved to the countries under mainly British influence. In Canada, all top end bikes switched from 27" to 700C in the late 70's. Apparently in the US, the change took a few extra years, because I remember having a devil of a time finding 700C tires and rims in the US in 1980, whereas any shop worth its salt had them in Canada. I also remember in the early 80's that the main differences between Miyata bikes sold in teh US and Canada was the difference in tire sizes. In fact the early "touring series" from Miyata, including the highly regarded Miyata 1000 apparently was sold with 27" tires in the US market. Good luck to any unwary tourist taking his bike to Europe for a tour: no shop on the continet would have had replacement tires.
Steven Maasland
Moorestown, NJ