Originally Posted by
loky1179
I was going off the millimeter specs on Sheldon's site, rather than actually doing the math:
BMX bikes Better models
22.2 .875" (7/8") BMX bikes Cheap models
21.15 .833" (nominally 13/16")
0.833" is 5/6" to 3 decimal places, not 13/16". That (0.833", or 21.15mm) also happens to be the size of the old (and hard to find) stems used on a few vintage bikes - post-1965 Chicago Schwinns, if I recall correctly, along with some others.
I believe this is a rare case of an error (probably a typo) on the late Sheldon Brown's website. But I guess I could be wrong.