'28' is a sew up tire label .
Imperial (now, British/American 'special relationship') would be 27" x 1.25".. ISO 630..
A 700C is 622 which in now also '29er'..
even having 27" tires, most of my tubes are measured in metric, where are you looking for tubes in inches?
when America is 'Made Great again' , the Foreign Metric system will be Illegal as will anyone speaking French or any other Language not using AP syntax.
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