I think 26” has been unfairly vilified and sidelined as a somehow unworkable wheel size. While I do own several bikes with 650b wheels, when I ride my 26” singlespeed, I’m honestly impressed by the quick acceleration, snappy handling, and good climbing ability. I run 2.3” tires, and tackle pretty much any surface I encounter with relative ease. Given the opportunity to convert it to 650, I can’t think of a reason why I would.