The ratio of the height of the tire to the width of the tire is the aspect rate of the tire. The formula is expressed as: flat rate =(the height of the tire/the width of the tire) x100%.
The original automobile tires had very narrow tread and large diameter, because the shape of the automobile was heavily influenced by the carriage and bicycle, which had very narrow and high tires. Narrow and tall tires, not only the safety of the operation is very poor, but also, because the tire’s bearing area is small, so, the durability is very poor. Therefore, to increase the width of the tire, reduce the inner diameter of the tire, has become the development direction of the tire and tire manufacturers to pursue the goal. The production of wide, flat tires required a great deal of skill, and it was not until about 1955 that this goal was achieved.
So, the tire from high to low, from narrow to wide, that is, after the tire short shape, what are the advantages?
First of all, because the tire widens, the contact area between the tread and the ground increases, so that the stability of the operation is enhanced, the friction coefficient increases, the braking performance is improved, and the durability of the tire is increased; Secondly, after the tire side becomes shorter, the circumferential slip rate of the car becomes smaller when turning, and at the same time, the toughness of touching the ground is strengthened, and the rotation performance is improved, so the turning performance becomes better. In other words, cars are less likely to have accidents even when they make sharp turns.
In addition, after the tire short, there is no big change in the overall height of the tire, the tire can be appropriately widened, can enhance the beauty of the vehicle, give a person a full feeling.
When the flattening rate is reduced from 70% to 60%, the turning performance of the vehicle is improved by 15% and the friction coefficient is increased by 10%. Here we need to remind you that when changing to a low flat rate tire, we must do the following:
(1)The outside diameter of the tire remains the same as far as possible, so that the best handling performance of the vehicle will not change, and the speedometer will not appear errors. Such as: Four-cylinder Jeep Cherokee, the original car uses P215/75R15 tires. In order to make the original car run more smoothly and look more beautiful, the original P215/75R15 tires can be replaced with P235/70R15 tires. In this way, although the tire width has been widened from 215mm to 235mm, But because the flat rate from 75 series to 70 series, so, the overall height of the tire basically did not change, so, the effect will be better. In addition, such as the ordinary Santana car using 185/70R13 tires, it can be changed into 195/60R14 tires, tire width from 185mm widened to 195mm, flat rate from 70 series to 60 series, rim from 13in to 14in, so that the vehicle will be more stable, Braking performance will be greatly improved, in addition, the appearance will be more beautiful and durable
(2) After the modification of the tire must not contact the car body, also can not exceed the fender. Contact with the car will occur accidents, beyond the fender will destroy the overall beauty of the car.
(3)Loading capacity can not be reduced.
In fact, after knowing how the flat rate of the tire is going on, you can convert the replaceable tires on your car according to the flat rate formula, which is also a very interesting thing.