Blair P. Houghton wrote:
> Tom Reingold <[email protected]> wrote:
>
>>I was a bike mechanic from 1978 to 1984. As far as I know, wider tires
>>never existed for 27" (really 630 mm) diameter.
>
>
> N.B.: 630 mm (24.8 inches) is the diameter at the bead seat.
>
> Add double the tire diameter (1-1/8 inches or 28.6 mm)
> and you get... 687.2 mm or 27.05 inches.
>
> Close enough for pack riding.
Ah, thanks for the extra information. Also, I believe the width rating
is not the width measurement when the tire is inflated. It is the
measurement of bead-to-bead distance when you flatten the tire on a
tabletop, divided by 2.5. At least that is what my memory says, from
back in those days. In practice, the width rating is often the same as
the width, but sometimes not.
Tom