Originally Posted by
no motor?
I'm with you (again), I had thought the width was measured at the widest part of the tire when mounted on a standard rim, and the standard for one company may not be the same as anothers (that's how they did it for automotive tires when I was in the tire business years ago). This style of measurement does make sense, and I may not have thought about it without this thread. I've been mounting thinner tires than the stock size for my bike for so long I don't even remember what it looked like with wider tires.
Schwalbe measures exactly as you describe (at the widest part of the tyre on a rim width they deem comparable, which I posted a chart for earlier). They allow ±3 mm on the widest tyre (60mm or 2+ inches). On the smaller tyres, less than 38 or around 1.5inches that are bang on the measurement ±1 mm. These are all published (including the height of the wheel/tyre combo.)
That's why I don't understand the OP's question. Perhaps it is different for other companies. I can only speak for Schwalbe and that's all I have done in this thread. Maybe other companies have ****ty QA/QC, I don't know, but I won't be a non Schwalbe tyre again.