i just went to the garage and measured a 559- 26" street tire on one of my bikes- 670mm.

i measured my 622- 700c tires touring bike and they measure out at 700mm.


hmm..... 30mm difference. why the 650b again if NOT to reintroduce a haughty and largely discarded tire size? Grant could have built on the 590 or 597 ISO rim sizes and serve the world bicyclists a huge favor.