Motorcycle suspensions were introduced at the starting of 20th century. At the very beginning suspensions were seen at the front wheel of a motorbike Motorcycle suspensions are also known as shock absorbers. This system helps the motorcycle to roll smoothly at different roads and for this riders can have a safe and sound journey. After many research it is found that telescopic fork is the most used suspension among all, other suspensions are the version of this suspension. Because of motorbike frame it wasn’t possible to place a rear suspension but after Second World War rear suspensions were placed at the motorcycles. Though in 1913 an Indian company started to set suspensions at the bikes but the road condition were not similar like these days so it wasn’t able to catch popularity that much. Nowadays many types of suspensions are seen because of better research but all their work is almost similar. According to the design and production coast different suspensions are used. In this discussion we will discuss about the most popular and familiar suspensions which are used and seen in Bangladesh.
Types of motorcycle suspension:
- Telescopic suspension.
- Telescopic suspension (upside down)
- Spring loaded hydraulic suspension.
- Gas filled or Nitrox charged shock absorber.
- Mono Shock
Telescopic suspension is used for the front suspension in almost every motorcycle today. A primary barrel and a slider bar are placed inside this suspension for giving free movement. It is loaded with a spring and fork oil inside to give the shock absorbing facility. Few advantages will also be found and they are, it is simple in design and quite cheap to construct; it is delightful than older designs using external workings and association systems; and last but not in the list it has a fresh and simple appearance which can be attractive to the bikers. More expensive and modern version of telescopic suspension is the "USD" (upside-down) fork suspension.
History of Motorcycle Suspension
Telescopic suspension-"Upside-down" (USD) forks
As the classification of USD forks it is also known as inverted forks and set up compared to telescopic forks. This suspension orients the fork tube, near the axle, and the outer slider up top, where it presses together for better handling and comfort. USD arrangement has two advantages, it decreases the additional weight of the motorcycle and it increases flexibility which can improve handling. Two disadvantages also found of USD fork and they are they are more expensive than usual telescopic forks and they are responsible to lose all their damping oil suddenly. This type of suspensions is generally seen at the sports category bikes.
Spring loaded hydraulic suspension
This braking system follows the set of laws of hydraulics. One kind of liquid named damping oil is used as the suspension base for this suspension. This liquid is placed at the hydraulic piston and it is in air tied condition. Outside the suspension there is a spring and this spring ensures that after the spring piston gets downward because of the pressure it comes to the right place again. Damping oil based suspensions contains a major problem, if it is used extremely then inside the damping oil champers bubbles are formed and this process is called Cavitations. By an example let us clear it out; if we shake a bottle fill up with oil then we can see bubbles are created inside it. Oil contains 10% molecules and because of extreme shaking or mortised all those molecules been released from their bond and bubbles are created. This type of suspensions loses their performance stability at long journeys. In our country at lower segments of motorcycles these suspensions are located. TVS Metro, Hero Splendor, TVS Flame etc are the biggest example. Except this in our country dual spring suspensions are also seen. It is called SNS” spring n spring Suspension or Dual spring suspension. At Bajaj CT100 this suspension can be seen. TVS Phoenix contains Series Spring Suspension but the main thing is this suspension is not so good at shock absorbing. Main work of spring is to bring back the piston to its real position.
Gas filled or Nitrox charged shock absorber
Because of cavitations Spring loaded hydraulic suspensions are not so durable and dependable at the long journeys. To solve this problem a canister filled gas is added with spring loaded hydraulic suspensions. Generally the gas which is used for this suspension s nitrogen and for this it is called Nitrox suspension. Major work of this gas is to prevent the formation of bubbles which are created inside the oil chamber. Because of this pressurized gas cavitations not occurred and for this reason at long journeys this suspension becomes more dependable, this Gas canister can also used as the store of gas and oil. For many reasons its better and this suspension not only increase the durability of the suspension but also it increases the safety and comfort. So if you have Nitrox filled shock absorbers then your feeling will be much better.
Mono shock absorber
A single shock absorber connected with the rear frame of a motorcycle to absorb the bumps of the roads known as mono shock suspension. Normally this single absorber is placed in front of the rear wheel and uses a linkage to connect with the swing arm. Honda Company refers this suspension type regularly as their rear suspension. The performance of mono shock suspension is vastly superior then the other twin shock absorbers though sometimes dual shock absorbers are better than Mono shock. Advantages of this suspensions are it gives better Cornering and Highway constancy, easy to tune and adjust and better handling and ride ability. At the disadvantages its maintenance is high, cannot carry excess load and less longevity than the other suspensions.
Advantages of dual shock
- Able to carry extreme load.
- Powerful shock absorber.
- Smooth riding experience even at the off roads.
- Low maintenance.
- Avoid load on the chassis.
Disadvantages of dual shock
- Not better for cornering at good speed.
- Need to compromise controlling at the high speed.
Advantages Mono shock
- Highway stability and cornering is superb.
- At smooth roads it is awesome.
- Adjusting and tune is easy.
- Handling and riding ability is good.
Disadvantages of Mono shock
- High price, high maintenance.
- Cannot carry heavy load.
Both the twin and mono shock absorber contains gas chamber to pressurize the piston and it allows a softer ride for everyday driving. Without these few more rear suspensions are seen such as early rear suspensions and plunger suspension etc. every sing manufacturers tries to place better suspensions for the rider’s better comfort and safety. Sometimes because of price and our own need sometimes we need to compromise this matter.