I used to ride as narrow a tire as I could find, usually 700X19 and, in the old days, 27"X1. I like 700X23, a little nicer ride and every bit as fast IMO.
Many others like 700X25 or even wider and report no drop in speed.
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“Life is not one damned thing after another. Life is one damned thing over and over.”
Edna St. Vincent Millay