The seatpost with shock absorber is an important part of the bicycle that connects the frame and the saddle. The construction of the device is simple. It consists of the seatpost, the shock absorber and a rubber dust cap. The dust cap protects the shock absorber from dirt deposits. The shock absorber is a steel spring that is located inside the pin. The shock-absorber is bolted to the seatpost and is connected to the frame with a clamp.
What is a shock-absorber seatpost for your bicycle?
A shock-assisted seatpost provides comfort when riding on unpaved and bumpy roads and softens shocks and jolts over bumps and irregularities. It adjusts the height and angle of the seat, contributing to the proper and comfortable positioning of the human body while riding a bicycle. When adjusting the cushioning device, the weight of the passenger and the type of road on which they are riding their bicycle are taken into account. The seat height can be increased on the highway, and decreased when riding on the dirt.
Varieties of cushioning seatpost
There are 2 types of bike seatposts:
- telescopic;
- Parallelogram.
To compare these types with each other, it is important to know what they are, what their advantages and disadvantages are.
Telescopic shock absorbers
An important advantage of the telescopic type is the low cost and simplicity of construction.
Telescopic suspension seatposts consist of 2 tubes. One of the tubes is inserted into the other and slides inside it, lowering and raising the seat. The stroke of the inner tube is 3-6 cm. The elastomer and the elastic spring are inside the tube and have a cushioning function: they soften the vibrations. But due to the strong friction between the 2 tubes the cushioning system has a low sensitivity. It does not smooth out small vibrations.
The disadvantage of the telescopic type is the mismatch between the directions of shocks on the bike and the directions of action of the shock absorber. Shocks occur strictly vertically, and the direction of the shock absorption processes – only along the axis of the pin. High loads cause the elastomer and spring to compress and the saddle to sag. Therefore, it is necessary to change the seatpost or constantly adjust the height of the seat, providing as far as possible its subsidence.
Parallelogram (lever) seatposts
These are more expensive and complex designs. The parallelogram mechanism consists of 2 levers attached by hinges. Between them is an elastomer that, when compressed, allows the seat to shift in any direction in the longitudinal plane. During the coincidence of the angle of displacement of the saddle and the direction of impact, the cushioning device smooths out the vibrations and contributes to a more comfortable ride on the bicycle. Because of the complexity of the mechanism, lever seatposts are heavier, but they are more reliable.
To visually see the advantages and disadvantages of each type, we present a table:
| View of a shock-absorbing seatpost | Advantages | Disadvantages |
|---|---|---|
| Telescopic | Low price Simple design Low weight of 400-700 grams |
Saddle sagging Low sensitivity to minor irregularities, rattling Low strength |
| Lever | Reliable and durable Smooth any shocks |
High price Complexity of design Heavy weight |
Material of manufacture
Seat tubes with shock absorber are made of different materials.
- The most popular material for bicycles is aluminum and alloys made of it. An important advantage of it is considered light weight and low cost. Aluminum is not prone to corrosion, withstands heavy loads, is responsive to the roughness of the road.
- Steel. This is a strong and inexpensive material. It is susceptible to corrosion. Carbon steel is more durable. It will not rust. Alloy steels have high strength characteristics, are characterized by anti-corrosion resistance. But alloy steels for the manufacture of seatposts are rarely used because they have a high cost. In addition, the product made of steel has a large weight.
- Carbon. This is the lightest material for shock-absorbing seatposts. Such prongs are used for racing road bikes.
- Scandium is a lightweight and expensive material. It is a high quality material.
- Titanium. Seatposts made of this material in the factory are rarely made because they have a high cost.
Advantages and disadvantages
Shock-absorbing seatposts have a number of advantages.
- They greatly reduce shock when riding a bicycle on uneven roads.
- A bicycle shock-absorbing seatpost is inexpensive. Choosing it will improve the performance of even an older bike. The price for a shock absorber is much cheaper than a new bike.
- A shock-absorbing seatpost is versatile. It is suitable for most bikes.
- This design increases riding comfort by reducing strain on the spine.
- Since using a design with shock absorber less fatigue on the body muscles, legs, the average cycling speed increases.
- The seat height can be adjusted remotely.
Disadvantages
- Shock-absorbing seatposts need to be constantly lubricated and cleaned.
- They have a large weight.
- The service life is small.
Popular manufacturers of shock-absorbing seatposts
Shock-absorbing seatposts are made by many well-known manufacturers. Let’s get acquainted with some of them.
- USE is a British company, producing seatposts for over 20 years, since 1999. The goods of this company are of high quality, made of lightweight aluminum. They are reliable, durable and flexible, not subject to deformation. Shock absorber contributes to a comfortable ride on any road. High quality shock absorbers are bought for world championships, Olympic games. USE tests shock absorbers. Products are durable, can withstand the weight of the cyclist 80-120 kg.
- A well-known manufacturer of the design is the company Kind Shock. Seatposts are made of aluminum alloys. There are models that adjust the stiffness by pressing a spring or elastomer. The weight of the seatpost varies from 410 to 490 g. The pin is fixed by one or two bolts depending on the model. Lever types are present. The company also makes models in which the seat height adjustment is done with a button on the handlebar.
- Suntour. This company makes lever-arm models with cushioning. They vary in diameter, weight. They have adjustable stiffness. They are made of aluminum and its alloys.
- Humpert is a German manufacturer, which produces quality products. Lever seatposts are shifted by 4 cm during the impact.
- M-WAVE is a Taiwanese company that produces high-strength aluminum prongs. The shock absorber is made of alloy steel. It softens bumps and shocks. Taiwanese company’s saddlebars are characterized by a long service life of the products.
- Kalloy is a company that is famous for high quality products for bicycles. One such high-quality product is considered a shock-absorbing seatpost. It reliably reinforces the saddle and withstands a high load. It can be adjusted for a particular weight class.
How to choose
When choosing a shock-absorbing seatpost take into account the wishes of the cyclist and financial capabilities. It is important to determine what price is acceptable to you. Based on this price select the appropriate product.
The weight of the rider will determine the diameter of the seatpost. The greater the rider’s weight, the larger the diameter.
The seatpost has a certain length. The seatpost should go inside the frame by at least 15-20 cm to support the weight of the rider. This connection will be stronger. But you should not take too long a pin, because it will add weight to the bike.
The material also plays an important role. Usually seatposts are made of aluminum 6061. But you can take a product made of carbon. It is lighter and of higher quality.
The shock-absorbing seatpost should be higher by 1-2 cm, because when the cyclist sits down, the shock absorber sags.
When riding in the city, you can take a telescopic, simple seatpost, but when cycling on dirt roads, it is important to use a more complex type of shock absorber – a lever one.
It is better to buy a seatpost with cushioning from well-known manufacturers to be sure of its quality.
Conclusion
Seatposts with shock absorber will help the biker to reduce the load on the spine, less fatigue and ride a long distance of several kilometers at high speed. Comfortable riding with a shock absorber will allow you to control the movement of the bike, not to experience rattling and jolting when riding off-road.
