Differences in motorcycle suspension system configuration


When it comes to the suspension equipment of a motorcyc […]

When it comes to the suspension equipment of a motorcycle, I believe many people know that it depends on whether the Motorcycle Parts is equipped with a forward fork or an inverted fork. Although most riders know that under the same conditions, the configuration of the inverted fork is relatively advanced, and the fact is also I can see the configuration of the inverted fork on the motorcycle model that even emphasizes performance. However, the person who can accurately tell the advantages of the inverted fork is not. Next, I will tell you the structure and characteristics between the positive fork and the inverted fork. .

Most performance models are equipped with inverted forks.

To understand the advantages of the inverted fork, you must first understand its structural principle. Both the positive fork and the inverted fork are both periscope-type suspension systems. In the periscope-type suspension, there must be several important components: , Lower triangular table, inner and outer tube of front fork, spring, damper, oil seal, earth seal, etc.

Peripheral front fork. (Right fork)

Upper Triangle

The upper triangular table in the front suspension holds the front fork at each end, and is connected to the frame with a bead bowl (bearing). In the street motorcycle models with high handles, the upper triangular platform usually also serves as a locking point for the handles to fix the handlebars.

Lower Triangle

The function of the lower triangular table is similar to the design of the upper triangular table, which holds the front fork together and is connected to the frame. In design, the lower triangular table will be vertically combined with the steering axis, and the upper part of the axis is locked with the upper triangular table with a nut to fix the front fork to the frame.

Front fork outer tube

The outer tube and the inner tube can move relative to each other. With the oil seal, the damping oil will not leak out. In addition, the outer tube of the upright front fork must also be designed with a caliper seat or locking point, and an axle lock hole, so that the caliper and tire can be installed on the motorcycle.

The locking point of the caliper on the outer tube of the positive fork.

Fork inner tube

The inner tube of the front fork is usually subjected to surface treatments such as electroplating. The purpose is to increase the surface hardness and achieve the function of anti-rust. It can also reduce the frictional resistance. Will use gold plating, it looks quite dazzling.

Oil seal, earth seal

The oil seal is the basic mechanical element used for the joint of the shaft, here is the joint of the inner tube and the outer tube to prevent the leakage of damping oil. On the oil seal, an earth seal will also be installed to prevent dust or mud from entering the oil seal and scratching the surface of the oil seal. design.

For motorcycles, the front suspension system needs to shoulder the steering function in addition to the shock absorption function. In addition to the up and down movement of the front fork of the motorcycle to achieve the effect of shock absorption, it must also be fixed on the triangular platform, and the motorcycle can be steered by the handlebar turning. Some drivers will also use the lock point of the triangle to adjust the height of the motorcycle to improve the motorcycle's cornering characteristics.

The front fork is fixed by a triangular platform, which can be telescopic to achieve the effect of shock absorption. Features of positive fork and inverted fork

Positive fork: relatively simple structure, easy maintenance and disassembly, and low cost.

Inverted fork: Stronger rigidity and lighter unsprung weight facilitates motorcycle handling.

Inverted front fork

In the 1990s, another type of front fork began to appear in mass production vehicles, advertised as higher overall rigidity and more sensitive suspension response, but the appearance was very similar to the original front fork. However, the new type of front fork is placed upside down, also known as an upside down fork. After the late 1990s, the inverted front fork gradually became the main equipment of performance motorcycles. Today, whether it is a racing car, a super sports motorcycle or a performance street motorcycle, most of them use the inverted front fork as the front suspension system.

Motorcycles that emphasize performance will be equipped with inverted front forks.

On the upright front fork, the diameter of the inner tube is the focus of the design. For example, on the SUZUKI GSX1400, in order to cope with the heavy vehicle weight and the rigidity required for high-speed cruising, a huge inner tube with a diameter of 46mm has appeared. In the design of the upright front fork, to increase the rigidity, it is necessary to increase the diameter of the inner tube and increase the weight of the suspension itself. When evolving from an upright fork to an upright fork, if the required rigidity is the same, the diameter of the inner tube can be reduced, which is the relative advantage of the upright fork.

The SUZUKI GSX1400 uses a fairly thick 46mm fork with an inner tube.

Increased rigidity

Increased rigidity has always been one of the selling points of the inverted front fork. Under the same inner tube diameter design, the inverted front fork can increase the rigidity than the traditional upright front fork. Therefore, under the same rigidity requirements, the inner tube diameter of the inverted front fork can be smaller, and the overall front suspension weight may also be lighter. The tire will be transmitted to the front fork faithfully in all directions from the ground, like the principle of leverage. The front fork triangle is the fulcrum. The closer to the fulcrum, the greater the torque will be, so it will be more The thick outer tube is placed close to the triangular table to make it have better rigidity performance.

Under the same conditions, the rigidity of the inverted fork is stronger.

Reduce unsprung mass

The unsprung mass is the mass below the spring in the suspension system. In the inverted front fork, the inner tube is designed below the overall front fork. In addition to the inner tube itself can be smaller in diameter, the mass is also considered lighter than the thicker outer tube, and reducing the unsprung mass is actually In the test, the vehicle equipped with an inverted front fork can indeed give a more sensitive front suspension response, which is why most models that emphasize performance use the inverted front fork.

The greater the M & m ratio gap, the lighter the unsprung mass and the more sensitive the suspension response.

Through the above explanation, I believe that everyone has a better understanding of the front suspension system. In fact, in addition to the periscope front fork and inverted fork, the front suspension also has HOSSACK, DUOLEVER, TELLEVER, TESI, RADD and other systems.