700c has been a very misunderstood term for a while now and we would like to clarify that for you. The most common issue with this term is confusing it with “700cc”. The 700cc is a term for motorcycles referring to their motor power. The words are very similar but the meanings are so different. The term “700c” is the tire size according to the French system. The “700” is stating the diameter of the bicycle tire and “c” is the width size of the tire. However it’s not 700 millimeters it’s 633 millimeters.
Also, another common mistake is that often riders confuse “c” with centimeters. 700c’s c does not have anything to do with centimeters.
The alphabetical order is coming from the old French system which starts with the letter “a” and goes through to “d”. Size “a” is the narrowest and size “d” is the widest width size for a tire according to this system. Except “c” all other sizes dropped and have not been in use for a long time but “c” stuck because of widely used.Generally you can use 28mm to 35mm wide tires on the 700c rims.
Another false assumption is that 700c and 29-inch tires are the same. Unfortunately this is not true. “700c” has the same diameter with a 29-inch tire. However, the width of the 700c is narrower than a 29-inch tire. Riders think because their diameters are the same size, the width will also have the same size. If you fall into this mistake your tire unfortunately won’t fit into your rim.