Many cyclists are care less on their current size of bicycle tire until they need to replace a new tube or tires (DIY). Two numbers that most important to determine the bicycle tires and tube sizes. Most common number we seen is
26″ x 1.95 , 26″ x 2.125, 16″x1.75, 20″x2.125, 700x23c, 700x20c
For example 26″ x 1.95 (kids bike – MTB)
26″ = The diameter of the rims
1.95 = The width of the tires (greater number means wider the width of tires)
For example 700x23c (road bike/fixie/hybrid)
700 = Diameter of the rims
23c = Width of the tires (greater the number, wider the width of tires)
Special case like (trolley, wheelchair, old style city bike) The tire sizes would be like stated like 24″ x 1 3/8. Usually, we have to strictly follow this tires size for replacement.
Where to check the wheel size?
Very simple. Every information of the bicycle tire imprinted on the sidewall of the bicycle tire. Look carefully, you sure can find it. Lastly, a proper replacement of tube size (diameter x width) to fit into the tire would enable the tube last longer. E.g If you tire size is 26″x1.95. You have to find a replacement tube which is similar size as your tire. You may replace a tube like range from 26″x1.9 – 26″x2.125.
What if no imprint numbers on the sidewall?
Just bring the whole rims if can not manage to take out the tires and tubes.
So, when you want to purchase tube from bicycle store, just tell them your bicycle wheel diameter and width of the size.