I'm planning to get back into commuting again on an early 70's Follis 172 with 27" wheels. The tires currently on it are just about the width I like for commuting. They are old Japanese 27" clinchers marked as 27 - 1 1/4, which theoretically should translate to 32mm wide, but they actually measure 29mm when inflated. I know that Japanese 27" tires were for many years marked as wider than they really were so that the makers could claim a lower weight for a given nominal size, but I'm not sure about the relatively few 27" tires made today. Can someone who is "in the business" tell me whether currently manufactured 27" tires are accurately marked? In other words, if I want a tire which will actually measure 28-29mm wide when inflated, should I buy a 27 - 1 1/4, or a 27 1 1/8 which in theory should be between 28 and 29mm wide? I'm specifically considering Continental, Vittorio, and Panaracer.
Regards,
Jerry Moos
Houston, TX