Generally speaking, the size of a bicycle is just like clothes. There are several sizes: XS, S, M, ML, L. The wheel size of a road car is generally 700c C, and 700c means that the circumference of a tire is 700cm. In fact, the circumference of a narrow tire is less than 700.

The wheel sizes of mountain bikes are generally 26 inches and 29 inches. The 29-inch wheels are actually 700c wheels with thick mountain tires. The wheel size of station wagon is generally 26 inches, 700c C, and there are many wheel sizes of urban scooters: common 26 inches, 24 inches, 700 c; Folding bicycles are 16 inch, 18 inch, 20 inch, 22 inch and so on.

The frame size of a car can be changed, but the generally matched wheel size will not change. For example, the wheels of the giant ATX770 S frame are 26 inches.

Extended data:

The bicycle model is represented by Chinese phonetic alphabet, followed by a group of Arabic numerals. For example, pa- 17, qf-65, za-4 1. It means: the first letter indicates the type of bicycle.

For example, P stands for ordinary type, Q stands for light type, Z stands for heavy type, S stands for racing type, X stands for small wheel type and T stands for special type. The second letter represents the style and specifications of the bicycle. Style refers to men's cars or women's cars. For example, the singular letters a(28 inches), c(20 inches), e(26 inches) ... all represent men's cars.

The letters b(28 inches), d(27 inches) and f(26 inches) all stand for women's cars. The letter followed by Arabic numerals is the serial number of the factory design.