2. Tire size – how to choose the right one?
Tire size is usually indicated in two ways: in millimeters (ETRTO marking, e.g., 37-622) or inches (e.g., 29” x 2.4”).
- Inch size: A common standard used by bike type, like 26" for mountain bikes and 28" for city bikes.
- ETRTO number: A more precise standard where the first number indicates the rim diameter in millimeters and the second the tire width. For example, 622-37 (also expressed as 37-622) means a 28" tire with a width of 37 mm.
How to choose the right size:
- Check your current tires: You'll find the size indication on the side of your old tires.
- Ensure bike compatibility: Not all frames support wider tires – check the maximum width!
- Consider wider or narrower: Wider tires add comfort and grip, while narrower ones roll lighter.
Common tire sizes and uses:
- 700c or 28" (622 mm) – Road, gravel, and hybrid bikes
- 29” (622 mm) – Mountain and gravel bikes
- 27.5” (584 mm) – Mountain bikes, some city bikes
- 26” (559 mm) – Older MTB models and some city bikes
If unsure, the ETRTO marking (e.g., 37-622) is the most reliable way to find a compatible tire. The first number represents the tire width in millimeters, and the second indicates the rim diameter.