The suspension has the following functions:
- Isolate the driver and the bike from the road irregularities and the forces applied on the bike;
- Keep the wheels in contact with the road, transmitting: power, braking and steering.
This work focus on aspects such as the various settings, behavior, maintenance, weight, production costs, etc.
- Telescopic forks, conventional or inverted;
- Double arm (wishbone);
- Other alternatives suspensions.
- Single-sided swingarm
- 2 sets spring / damper;
- 1 set spring / damper: - Direct effect OR - Multi-link.
Construction details of front suspension:
Telescopic forks (Figure 1):
In this case the spring (1) and damper (2) are embodied in the suspension jars(3) being driven by and bottom of the sheaths (4). The jars are maintained in position by two parts which are called T's suspension (5).
In the case of the figure next to have an inverted fork, as the wheel is fixed to the jar being below that of the sheath.
These two types of configuration are the most commonly used in production vehicles, and is mainly applied to conventional telescopic fork.
Double arm (wishbone) (Figure 2 and 3):
This type of front suspension is rarely used in production models. This system consists of two overlaid (identical to the system found in an automobile) and the spring and damper (2) being concentric are fixed between the lower triangle (1) and frame (3). The direction is in the wheel axis (4), being led through a tie rod (5). We have as aproduction model bike example the Bimota Tesi.
Swingarm (Figure 4 and 5):
This suspension consists in an arm (1) that anchors the wheel to the frame (2). In the frame is connected to the spring and shock absorber (3) which are concentric in this configuration. There is also a bar (4) which transfers to the wheel the turning force. Again, as in the previous the steeringis made in the wheel hub (5). This suspension is used, for example, by Yamaha in the GTS and is named Omega (fig. 5).
Telelever (Figure 6):
This suspension consists of a telescopic fork which has only the function of allowing wheel travel straight forward and steering effort (the handlebar to the wheel) and a triangular horizontal arm which transmits the forces of the suspension spring / shock absorber, over a concentric time. To this suspension is also mounted a steering damper. This system is currently used by BMW.
Other alternatives suspensions (Figure 7, 8 and 9):
There are many other types of suspension tested prototypes more or less known, more or less efficient.
The images are examples of alternative suspensions.
Construction details of rear suspension:
Mono arm (Figure 10):
In this case the rear wheel is grounded on one side, placed one spring / shock in the central position.
Swingarm with 2 sets spring / damper (Figure 11):
The oscillating arm of the suspension is formed by two bars on either side of the rear wheel and a set spring / shock absorber and each frame.
Swingarm with a joint spring / damper effect and simple scaling effect (Figure 12):
In the case of single-acting construction is completely identical to the previous one, except for the placement of the spring and damper, in this case is in a central position.
When an oscillating arm to effect scaling of the set spring force of the shock absorber is applied to a lever system.
Characteristics of each configuration
Telescopic fork: This is the configuration most used today in the front axle, due to the fact that low-cost construction.
This type of suspension has the major disadvantages in that when braking sink and twist.
The fork inverted solves the problem of torsion, as this has a greater rigidity. It also has the advantage of reducing the unsprung mass, increased comfort.
Double arm (wishbone) being a little system used has a major drawback which is that of removing some of the sensitivity direction and being of a constructive complexity which leads to their higher cost.
This suspension has also the characteristic of having a fairly neutral behavior in all working situations.
Swingarm (front axle):
This system's main advantages:
- Driveability while it is a motorcycle larger;
- Decrease of the height of center of gravity;
- Increased sensitivity to the previous system;
- It has the disadvantage that as the twist telescopic forks.
The biggest disadvantage of this system is its higher price of construction.
- Oped to sag lower gear ratio of braking force due to longitudinal arm;
- Higher rigidity than the telescopic forks;
- In this system the fork has practically no maintenance;
- Low maintenance cost.
The biggest drawback is the failure to conduct efficient sports, or just efficient motorcycles sport-tourism.
Mono arm (rear axle): Its great advantage over conventional swingarm rear wheel that is far more easily removable.
It also has a lower weight, but undergoes a twist to have only one support.
Swingarm with 2 sets spring / damper: This system was used as will some time ago, but has been abandoned due to its drawbacks. For example: higher price, more uncomfortable, uneven operation of both units.
Swingarm with a joint spring / damper simple effect: This system is also now used less and less, can overcome the shortcomings of the previous system.
Since the major drawback the fact that a direct suspension.
Swingarm with a joint spring / damper effect Gear: The characteristics of this suspension are practically the same simple effect.
The advantage relates to the gear ratio of the course of decreasing the size of the suspension spring / shock absorber, this increases the comfort of the vehicle.
This is the most rear suspension system currently used in motorcycles.