mpetry912 

So here is an interesting thing building on the discussion above. There has been some experimentation with alternate wheel sizes, to be sure 650c triathlon bikes - but back in the late 70s Cino Cinelli experimented with a smaller wheel size also. A very rare Cinelli model is the "Riditto" - it is mentioned in the Herlihy interview - has slightly smaller wheels, long cranks and very steep angles (76 deg head angle). Cino felt that this was a more evolved design for modern roads which are smoother than the gravel or dirt on which the 27" wheels evolved.

From the Cinelli timeline at Velo-Retro
1975-76
Mod. Ridotto utilizing 26 inch wheels and extra-long cranks. Cino Cinelli is interviewed by David V. Herlihy and advocates the use of 26 inch wheels and extra-long cranks as the ideal road bike, and evidenced by his personal bike (mod. Ridotto or reduced). "27 inch wheels were designed fifty years ago when we had much poorer roads," he groused, "It just doesn't make sense that we still ride these wheels today." Cino adamantly maintains that cyclists would benefit from the higher cadence that goes along with smaller wheels, and that longer cranks provide better leverage.

I have no idea how many of these bikes were built. Maybe 4 or 5 total. I saw one years ago at Ron Boi's shop in Chicago. When this one became available I had to have it. It's the only bike in my collection that I don't ride - the tires are NLA ! I have a spare set :- )

Salamandrine 

700c and 77" are essentially the same size. The radii differ by only 4mm. Realistically, that isn't significant. Any hypothetical difference in rolling resistance due to size alone will be completely dwarfed by differences in rolling resistance between different tires, and different tire pressure.

noglider 

Agreed. The conjecture on how they ride differently is madness.

clubman 

I'm no physicist. A 60's F-frame Moulton is a damn fine ride but it's no racer. The later Moulton space frames were competitive but expensive. Diamond frames turned out to be both efficient and economical and the wheel size appears tied into that design when you assess average rider size, centre of gravity, weight and many other things I'm sure.

IIRC, Dunlop invented the 27" wheel to (successfully) carve out a bigger share of the marketplace, maybe post WW II? Can't find a date online.

Oddly, the main standard for adult Canadian bike wheels throughout the 20th century were equivalent to 700c, clinchers and I believe tubulars as well.

Kuromori

Moultons provided too much of a drafting advantage in racing and caused the UCI to ban tiny wheels. Like it or not the UCI has a big effect on cycling norms even for noncompliant bicycles and essentially defines the bicycle overton window.

ThermionicScott 

Hilary Stone puts the year at 1935: Constrictor Conloy rims

BikeWonder

Thanks for the discussion! I appreciate the input and perspectives.

it might have been an obvious thing to ask, but I wanted to know more from those who have more experience in the C&V and biking culture. Always happy to learn new things.