Originally Posted by
HerrKaLeun
what you (or the manufacturer) calls 28", is the very same what 29" or 700c is. That tire will fit on a rim marketed as any of the 3 designations provided the rim width is within reason of tire width. 28" has been standard wheel size for regular sized adults for ages. it is just that when MTB were "invented" there were no wide tires available in 28", so they used the cruiser 26" balloon tires. At some point they came back to 28", but to be cool called it 29".
Most of everything in the bike industry is around available tire sizes. A frame, even rims, can be jury-rigged in a garage to any size one needs. but you can't make your own tires.
The problem with thinking modern 29r design was always around isn't regarding tire diameter, it's rim width. A modern 29r mtb tire won't fit a previously available 700c rim. Just like my 4.6" fat tires don't fit on standard 26r rims, even though they are nominally the same size.