A tyre is the part of the wheel which makes contact with the ground. It sits on the wheel rim, and has an inner tube inside. There is also a type of wheel called the tubeless wheel. On tubeless wheels, the tyre and rim form a single, airtight unit, with no inner tube. Tyres are made for different types of bikes, riders, conditions and terrains, so your choice of tyre will depend on your size and cycling discipline. Each model of tyre has its pros and cons and is designed for a specific use.
Tyre diameter is measured in inches. A 14″ tyre is a very small tyre, made for junior bikes or some foldable bikes. A 20″ tyre is designed for BMX bikes. 26″ is the standard size of tyre and is used for almost all adult hybrid and mountain bikes.
In terms of width, a very thin tyre is 1″ wide while a very wide one is 2.7″ wide. These are the extremes of tyre size that you can find on the market. Most city bikes need 1.5″ wide tyres. For mountain bikes, the most common width is 2.0″. The tyre size is written on the tyre itself. For instance, on a tyre with a 26″ diameter and 1.9″width you will find: 26×1.9.
Road and Race Tyres
For road and race bikes, the wheel’s diameter is measured in millimetres. The most common size is 700 (28″), but 650mm wheels are also sometimes used.
The width of the tyre is called the “section”. Tyres on the market range from from 18mm, (very thin) to 25mm (wide). 35mm tyres, for cyclocross, are also available.
Hybrid and City Bike Tyres
Slick tyres are the best choice for city use. These tyres should be almost completely smooth. The pattern visible on the tyre is designed to evacuate water in case of rain or strong humidity. They need to be well inflated (accordingly to the manufacturer’s instructions). Indeed, the more inflated a tyre is, the less friction there will be between the tyre and the ground, making it easier to cycle at higher speeds with less effort. On tarmac roads, slick tyres have good grip and are very efficient.
In the countryside, or if you plan to ride your bike equally inside and outside the city, relatively smooth tyres are also advisable, but patterning on the tyres is vital to prevent you slipping on mud or water. Side notches will also help prevent the bike from slipping when turning.
Road Bike Tyres
Depending on how you use your road bike, some of the tyre‘s characteristics, such as weight, width or ideal pressure for efficiency, will be more important to you than others. On firm or very smooth surfaces, you can use tyres down to 18 width. The most common width is 22 or 23. If you are not used to thin tyres, or prioritise comfort over performance, 25-width tyres will be a good choice. If you do cyclocross, you will need specially designed tyres which are thin but serrated, and your choice of width will depend on the quality of the track: the wetter and rougher the terrain, the wider and more serrated the tyres must be. Pressure is a key parameter, as thin tyres must have an optimum efficiency on the road. Refer to the manufacturer’s instructions for further details.
Mountain Bike Tyres
Mountain bikes tyres can be very different from one use to another and depending on the discipline. The choice you make when selecting your tyres is then crucial as using the wrong tyres might even be dangerous.
Mountain bikes tyres can be very different from one use to another, and different again depending on the discipline. The choice you make when selecting your tyres is crucial, as using the wrong tyres could even be dangerous. Tyres for recreational mountain biking need not be overly knobbly, especially if you also use your bike in city and in the countryside. The tyres should have some texture, but nothing too deep. The thinner your tyres are (1.7″ to 1.8″), the easier they will be to use on easy-access terrains like roads and paths.
If you are regularly riding in the forest or in the rain, you will need wider tyres (1.9″ to 2.2″) with a deeper treads. For freeride, downhill or enduro cycling, mountain rides or on very rough tracks, your tyres need to be even wider (2.3″ to 2.7″). The tread should be deep and rough, with side notches to ensure good grip when turning.
Junior Bike Tyres
It is important to choose a classic tyre (plastic is not advisable), as this will allow your child to keep maximum grip on the ground. Make sure you choose the right size, depending on the child’s height.
Choose 20″ tyres designed specifically for BMX as they will be stronger. Depending on your discipline (race, dirt or recreational), you should choose a different type of tyre: for concrete, you should select a smoother tyre than for dirt.
There you have it, depending on which bike you have you’ll want to look for a different tyre in Decathlons tyre section.