Cycling: knowing how to choose your tires and juggling numbers

As with a motorized vehicle, each type of bicycle has its tire (or almost). Midi Libre – co-owner

Inches, millimeters, height, rim width, valve… For the layman, choosing a new tire for your biclou, or an inner tube can, sometimes, border on the Kafkaesque. So this week, Le Nez dans le Handlebar comes to your rescue and breaks everything down for you. Come on, saddle up!

Before choosing a tire or a new inner tube, you absolutely must identify the correct numbers. This is where the thumbs come in and it’s a hassle!

One inch is equal to 2.54cm and you will find wheels in 26, 27.5, 28 or 29 inches (from 12 to 24 for children's bikes). But it's insufficient. Because the measurement in inches is the diameter of the wheel at the top of the inflated tire! And a 28 or 29 inch wheel will be mounted on the same rim. Misery!

Only one solution: whether on tires or inner tubes, locate the numbers noted as follows: 23-622, 35-622, 40-559, or on old bikes: 32-584. We are talking here about ETRTO (European tires and rims technical organization).

Let's be specific!

The first number is the width of the inflated tire in millimeters. That is 23 to 28 mm (road bikes), 32 to 50 mm (city bikes), 32mm to 50 mm for gravel bikes.

The second number indicates the exact diameter of the rim, in millimeters. This diameter is measured at the exact point of contact between the rim and the inflated tire (i.e. inside the rim).

This is the most precise measurement for purchasing a tire or inner tube, it is the rating that allows manufacturers of tires, rims and inner tubes to measure their accuracy. #39;be fitting. The most common diameters are: 622 mm (road, city, large mountain bikes or hybrid bikes in 28 or 29); 559 mm (MTB in 26); 584 mm (27.5 mountain bike and some old bikes). So on…

Width: distrust!

With these dimensions, there is no risk of making a mistake, provided you choose the right valve!
Presta: fine bicycle valve; Schräder: car valve. The weird valve with a small tip and a wide ring not to unscrew, it's the Dunlop!

Last thing: on the rims, you will find this diameter but also the interior width of the rim! And there, be careful, because you will not be able to fit just any section of tire depending on this width. If in doubt, contact your favorite bicycle retailer, who has the regulatory correspondence grids.

Section produced with Le Criquet de Talus velociste at 3, rue Lunaret.