Conti i think label their tyres as both 700c and 28".
I thought 28" was more commonly quoted in reference to tubular tyres but really meaning the same size as 700c. ie if you had a mounted 28" tub and a mounted 700c clincher of the same width etc they would have the same overall diameter/circumference.
29" as in 29er and 700c have the same erto of 622mm but 29er tyres are wider/chunkier/more mtb based.
Conti i think label their tyres as both 700c and 28".
I thought 28" was more commonly quoted in reference to tubular tyres but really meaning the same size as 700c. ie if you had a mounted 28" tub and a mounted 700c clincher of the same width etc they would have the same overall diameter/circumference.
29" as in 29er and 700c have the same erto of 622mm but 29er tyres are wider/chunkier/more mtb based.