Originally Posted by
DArthurBrown
The older Schwinns commonly had 21.1 mm (7/8") quill stems........Fussing with 7/8 stems is a pain in the butt......... The only other good option for ditching the 7/8 stem is to get a new fork and headset locknut that are 22.2 mm.
21.15mm quill stems, aka .833", equals 5/6." 22.2mm quill stems, aka 7/8", are the most common size for one inch forks.
21.15mm equals 5/6 inch. 22.2mm equals 7/8 inch.