When the bicycle is upright, you will be able to measure the bike wheel without the bike tipping onto you. If you are measuring the bike alone, a retractable metal tape measure will be sturdier than a plastic tape measure while leaving you a free hand. This measurement is the wheel's radius, or half of its diameter. Multiply the length by two in order to calculate the tire's diameter. With the exception of BMX models, most adult bicycle wheels are between 26 and 29 inches in diameter. If your tire is mounted, check the sidewall to find the measurement. The distance is the tire's width. It can vary greatly depending on the tire's intended use. Generally, the wider the tread, the rougher the intended terrain, while narrower treads promise a smoother, faster ride. Remember when purchasing a new tire that traditional, or standard sizes place the diameter first, followed by the width. For example, a tire sized 26 x 1.75 would have a 26-inch diameter and a 1.75-inch width across the tread.

How would you rephrase that briefly using Indonesian?
Tegakkan sepeda dengan menyandarkannya pada dinding atau menggunakan standar. Ukur dalam inci jarak dari tanah sampai bagian tengah ban. Ukur bagian datar ban memotong tapak ban dari satu sisi ke sisi lain. Saat membeli ban baru yang tradisional atau standar, sebutkan diameter diikuti lebar.