Originally Posted by Sheldon Brown
Actually, it didn't. The "road bike world" was using that size since the 19th century. Dunlop introduced the 630 mm (27 inch) size sometime in the 1950s for marketing reasons, but it never caught on outside of English speaking countries, and in the 1980s it was pretty much abandoned.
Strange. If that's the case, then why do so many road bikes from the 70's and 80's have 27" wheels? Even models made outside the Imperial measurement dynasty? For example, I had a Takara. That's not Takara, Kansas if you know what I mean.