Wider tires are better in a bike

Narrow vs wide

The rolling friction resistance is less dependent on the type of clincher or tubular tire than on other factors, especially the air pressure. If the load, air pressure and tire material are the same, the narrow bicycle tire compresses more. This is due to the fact that narrow bicycle tires have an elongated, narrow contact area, while wide tires, on the other hand, have a longitudinally short but wider area. It follows that a narrow tire will impress more strongly in the contact area with the ground. Any excess work that is converted into heat is lost to the drive.

Narrow bicycle tires can withstand a significantly higher pressure than wide tires. When one speaks of the better rolling behavior of wider tires, this primarily refers to tires of different widths that can (can) be driven with the same pressure, e.g. a 20 mm wide and a 25 mm wide racing bike tire. The latter is quite comfortable and rolls smoothly at, for example, 6 to 7 bar pressure, while the narrower tire can tend to bottom out under 6 bar.

The influence of tire width on rolling resistance is often overestimated, as is the radius. The flexing of the tire is mainly responsible for the increase in rolling resistance, so that here the wider contact surface could be compensated for by reduced friction. The higher the speed, the greater the share of air resistance in the total resistance. Therefore - the higher the speed of the air flowing onto the front surface of the wheel - the tire width plays a decisive role (of course in connection with the rim profile). The right compromise between rolling resistance (=> wide tires) and air resistance (=> narrow tires) must therefore be found.

The type designation SK (Skin = skin) stands for light, thin side walls that reduce rolling resistance and weight and therefore run particularly smoothly.

So that the Skinwall tires are puncture-proof, the carcass, i.e. H. the tire body, made of a reinforced, tightly set fabric of cotton, kevlar or other threads. The carcass density is measured in threads per inch (TPI). For simple tires this is often 24 TPI, for higher-quality bicycle tires between 50 and 67 TPI

Text source: In parts Wikipedia.org