The full size of a bicycle wheel consists of the rim diameter and the thickness of the bicycle tire. Traditionally, this parameter is measured in English inches - today there are no more than six of the most common bicycle wheel sizes - 20, 24, 26, 27, 28, 29 inches. So how do you know the diameter for your bike?
Size classification
The wheel diameter is 20 inches for kids, folding and BMX bikes, and 24 inches for freeride and similar extreme sports. Mountain bikes, city bikes and touring bikes have a wheel size of 26 inches, while on road types it reaches 27 inches. Road and hybrid varieties, as well as traditional Soviet models, are 28 inches in diameter. The new standard for mountain bike wheels that is gaining popularity is 29 inches.
The most common size for modern bicycle wheels is 26 inches.
Tires with diameters ranging from 27 to 29 inches fit on rims that measure 622 millimeters. The change in the total wheel diameter is solely due to the thickness of the bicycle tires. To determine it, you need to look at the size of the tires that were previously installed on the bike. Typically, the size of bicycle tires is located on the sidewalls (as in car tires). Its size and the rim diameter of the wheel should correspond to each other as much as possible.
Measuring the size of a bicycle wheel
To find out the parameters of the bicycle wheels, you need to measure the diameter of the seat. This will require a thin, soft wire or steel tape that is placed on the first shoulder, which serves as a seat for the tire, and wrapped around its outer surface until a fully closed ring is formed. Then carefully remove the tape from the rim, stretch it in a straight line and measure its total length with a tape measure. The resulting figure is divided by 3, 14 - this is the diameter of the wheel.
The inner tire size can also be determined by subtracting twice the tire cross-sectional value from the outer diameter.
Another very accurate measurement method is to draw a straight line on a horizontal flat surface. Along this line, you need to drive one wheel revolution, pressing on the steering wheel - while a mark must be made on the tire in advance (if you wish, you can drive not one, but several revolutions). Then you just need to measure the segment that the wheel has traveled with a tape measure. To get the most accurate result, you can repeat the ride several times and calculate the average, which is the size of the bicycle wheel.
