Before buying a spare or replacement tire, you should first measure your bicycle tire. In fact, measuring tires is a standard component of bicycle maintenance. Measuring tires and rims can be done in two simple ways. Sometimes you need to know the circumference of the tire. This can be done easily in several ways.
Step
Method 1 of 3: Measuring Using the Standard Method
Step 1. Stand the bike by leaning it against a wall or using a standard
Standing like this, you can measure the tire without the risk of being hit by the bike. If you are going to do it yourself, it is better to choose a building tape rather than a sewing tape. The building meter is more powerful and can be used with one hand.
Step 2. Measure in inches from the ground to the center of the tire
This is the tire radius or half the diameter. Multiply by two to measure the diameter. Apart from BMX models, most tires are 26 to 29 inches in diameter.
Step 3. Measure the flat part of the tire cutting the tread from one side to the other
This distance is the width of the tire. Tire width varies depending on its use. Generally, wide tires are used for hard terrain, while narrow tires create a smooth and fast driving experience.
Step 4. When buying a new traditional or standard tire, specify the diameter followed by the width
For example, a tire measuring 26 x 1.75 means that it is 26 inches in diameter and 1.75 inches wide.
Method 2 of 3: Measuring Using the ISO Method
Step 1. Find out the method used to measure your bicycle tires, the standard method or the International Organization for Standardization method
ISO uses millimeters to measure bicycle tires. If you don't have a meter with the metric system, be aware that one inch equals 25.4 mm. Calculate tire size with a calculator. Multiply 1 inch by 25, 4.
Step 2. Make sure the bike is leaning against a wall or bicycle stand
Measure (mm) from the center of the tire to the inner circumference of the bicycle. Multiply by two to get the diameter. Most adult bicycles are 650 to 700 mm in diameter.
Step 3. Measure the width in millimeters
Use the same process as the previous method. Measure the width of the tread cut from one side to the other. Keep in mind that tires of different widths can be fitted on the same rim as long as the differences are not too noticeable.
Step 4. Remember when measuring using the ISO system, the width is written first and followed by the diameter
For example, a 53.3 x 700 tire means that the tire is 53.5 mm wide and 700 mm in diameter from one side of the tire's inner circumference to the other.
Method 3 of 3: Measuring the Perimeter
Step 1. Measure the circumference of the tire or the rim of the tire so you can set the speed meter, odometer, GPS or computer
Like a car, if you change the tire size, the speed meter and odometer will give incorrect data. Bicycle equipment must also be adjusted according to tire size. You need to know the circumference of the tire when you buy a distance meter or when you want to change the settings of the meter you have after changing your tire size.
Step 2. Calculate the circumference by multiplying the diameter and pi
The circumference can be known quickly if you already know the diameter of the tire from the outer circumference of the tire. Pi equals 3.14. The circumference of a 26-inch tire can be calculated by multiplying 26 x 3.14. The circumference of the tire is 81.64 inches.
If you know the diameter and width, you can look up the circumference measurements using a diagram available online
Step 3. Measure the circumference using thread
If you don't know the diameter of the tyre, measure the circumference by wrapping the thread around the rim of the tyre. Mark or cut where the two ends of the thread meet, then measure the length of the thread to find the circumference of the tire.
Step 4. Make dots using paint on the tire tread
Gently push the bike straight at least two turns. Make sure the paint sticks to the floor twice. Measure the distance between the paint spots to determine the circumference of the tire.
Tips
- When measuring the diameter of the tire, do not allow the tire to rotate as this can reduce the accuracy of the measurement.
- Tire size is usually printed on the side of the tire and is written in diameter x width, for example: 27 x 1.5. Size 27 x 1.5 is not always the same as 27 x 1.
- If using the standard method, the diameter must be an integer. If you get a fractional value, round to the nearest inch.
