The so-called diagonal tyre refers to the tyre whose cords are arranged diagonally, hence its name. The entire carcass is composed of multiple layers of diagonally crossed nylon cords. The tyre crown and sidewall belong to the same ply, which makes the tyre stress concentrated. The deformation of the sidewall is directly transmitted to the tread, leading to unstable ground contact area and poor ground grip. Moreover, the uneven stress on the tyre tread causes serious wear in the middle and short service life of the tyre.
In addition, the diagonal tyre is composed of nylon cords with poor thermal endurance. After running for many times in the alternating environment of cold and hot, the nylon cord becomes fatigued, reducing the tensile force and causing a sudden tyre explosion, which poses a great safety hazard. A lot of tyres that seem to be in perfect condition suddenly explode, causing a huge impact on driving safety.
Also, diagonal tyre is with high sidewall stiffness, poor comfort, high tyre temperature during long-distance and high-speed driving and poor heat dissipation, so it is not suitable for high-speed driving.
Radial ply tyres are commonly used in cars nowadays because of their outstanding advantages such as better ground grip and the stability at high speed, while diagonal tyres have basically been eliminated with only a few low-speed and heavy-duty trucks or construction machinery still in use. However, there are still a few things to note when using the radial ply tyres:
1. Due to the thin sidewall, low lateral strength and poor support of radial ply tyre, you need to pay attention not to damage the side of tyre, otherwise it will lead to early scrap.
2. You need to strictly maintain the standard pressure required by radial ply tyre factory. The inflation standard of radial ply tyre is higher than that of diagonal tyre. When it is inflated at the same pressure as a normal tyre, it will appear to be under-inflated. It should also be noted that it is not allowed to reduce the normally elevated tyre pressure during driving.
3. Radial ply tyres and diagonal tyres should not be installed in the same car, because the different radial elasticity and sliding distances of these two kinds of tyres will cause different rolling radius. It is also not allowed to install radial ply tyres on the front wheels and diagonal tyres on the rear wheels, otherwise it is easy to swing the car tail when turning on the expressway, especially in rainy days.