Bicycle front fork: structure and classification. (2023)

Bicycle design has been changing and evolving for over two hundred years. The fork is an important part of the bicycle and its invention was a significant milestone in the development of the bicycle. The front fork of a bicycle is an integral part of the design. Not so long ago they were all the same. But now it's not just a part of the bike, it's a multifunctional mechanism that holds the front wheel, provides direction changes while riding, absorbs and dampens vibrations on rough roads.

What's in the front fork of a bicycle?

Bicycle front fork: structure and classification. (1)

Bicycle manufacturers are always looking for new ideas to improve the front fork. The question of choosing this part of the bike is immediately asked to a cyclist. A high-end or mid-range fork can cost a third of the cost of a bike. To understand whether an expensive fork is necessary or an inferior fork will suffice, it is worth considering the user experience, riding style, purpose and equipment of the bike.

Every cyclist must face the need to understand the device of his iron horse. When repairing the bike, it is important to understand the function of all parts and know their names.

The working principle of the fork is simple. The structure of the front fork is divided into 4 parts:

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  1. shock absorber– the element that carries the load while driving. Many models use a spring of different stiffness. The spring stores compression energy when hitting an obstacle. They come in twisted metal and air (a hydraulic chamber acts as a spring).
  2. Shock absorber – the part responsible for quick shock absorption in case of small irregularities. It is used to reduce spring return. There is no damper on cheap mechanisms. There are different types of shock absorbers: Quasi, elastomer, oil.
  3. Body - the part consisting of staff, crown, "legs", "pants" (where the "legs" are inserted), gusset (or gorilla, connects the "legs" into a whole).
  4. Accessories are switches, settings, brackets, handles.

In addition, the bicycle front fork device is divided into external and internal. External Includes: Bar, Crown, "Legs", "Pants", Disc Brake Assembly, Brake Brakes,dropouts. And the inside: anthers, mounts, guides, stiffener, bump blocks, springs, shock absorbers.

Types of bicycle forks

Bicycle forks are divided by shock absorbing device and design features.

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Bicycle front fork: structure and classification. (2)

Depending on the version:

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  • single crown. Installed on bike models forTo go biking, Trail, as well as models for Enduro and Dert.
  • two crowns Its “legs” reach the second jumper. Used in freeriding andDownhillmodels.
  • inverted. Classic models have legs up and trouser legs down, but here it's the other way around, legs down and trouser legs up. This is to reduce unsprung weight (which lies beneath the shock). The less weight there is on the wheel, the better the damper works and the less it gets stuck on small obstacles. This is a more professional and more expensive modification.
  • With one leg. Have a cantilever front wheel mount. They can be telescopic, lever and rigid. Due to the unique design, it was possible to increase the steering column and outer tube and use a double crown. The device does not slip, but rolls gently. Its operation is unaffected by any external factors other than the road. Disadvantages include high cost and the inability to install rim brakes.
  • inverted type. Used on hardcore freeriding bikes.

The basic classification of forks:

  1. Rigid or rigid. The most primitive variant. Give the opportunity to accelerate on flat asphalt. There are: carbon, titanium, steel, iron, aluminum. Used on bike models where front fork damping is not as important as pedaling power transmission. It is not suitable for off-road driving. Under heavy loads, the project will quickly fail.
  2. Damping. Responsible for shock absorption when driving off-road. Universal design that offers a comfortable ride in various conditions. A large shock absorber stroke does not have the best effect on speed and cornering stability.

Classification of front forks by type of shock absorber

Damper mechanisms come in different designs, their design determines the performance characteristics:

The cheapest option is spring. Both "legs" contain springs and there are no adjustments. It works on big bumps, but not small ones. Heavy, inefficient and short course.

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Spring Elastomer is a more advanced version. Inside the “pants” there is a spring and an elastomer (elastic) that acts as a shock absorber. Sometimes there is a mechanical blockage when the device stops compressing. The advantages include ease of maintenance and low cost. The disadvantages include not very smooth operation, intolerance to low temperatures, and after 2-3 years the fork completely loses its properties.

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In spring oil, the oil acts as a shock absorber. This is a higher quality grade than the first two varieties. Depending on the manufacturer, they are supplied with an open or closed cartridge. The open one is useful, the closed one is not. Their advantages are that they are reliable, unpretentious and work well in any weather. The minuses are heavy, the other options are lighter. This is a good option for those not willing to pay extra.

Air models are considered more profitable if we take into account the price and service. Inside is a sealed chamber into which air is pumped. This fork cushions large and small bumps. The ride will be comfortable, but off-road it's not the best option. The disadvantages also include a short service life. Also, you need to pump air into the chamber from time to time. With aggressive users, the design will quickly wear out and fail.

The oil-air models withstand even the smallest bumps. They have a wide range of configurations for non-standard weight riders. With these forks, the springs are replaced by air. These models require regular maintenance. They also require an additional investment: a high-pressure pump is needed. The mechanism works with air pressure, applying less pressure makes the fork "spongy" and increasing the pressure makes the fork stiff. Depending on the weight and preferences, the device adapts to the driver.

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The longer the stroke, the more obstacles the fork can handle. The shorter the course, the more precise the steering and the easier it is to drive uphill – tips for learning.

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The front fork of a suspension bike is heavier than the hardtail versions because it is made up of many parts. In order for all these parts to function smoothly, they need to be lubricated regularly. The more the bike is used, the more often you need to lubricate the fork, but at least once a year.

repair and maintenance

Bicycle front fork: structure and classification. (3)

If not every cyclist is able to repair the front fork himself, then definitely everyone can cope with the maintenance. The process consists of the following steps:

  1. remove construction. There are two types of attachment. More often they are threadlessly connected. You can remove the device by loosening the two screws. The chained method is rarely used.
  2. Clean the mechanism. Dust covers and hoods get very dirty. The accumulation of debris causes damage. Clean the mechanism if no oil is leaking from the outside. If oil leaks, the fork must be repaired.
  3. Substitute. There are three things that need to be changed:
  • oil (depending on the season, driving style);
  • springs (with active use, springs lose their properties and become not as stiff as originally);
  • Air (air and air-oil forks need to be pumped a little less often than camshafts).

There are no disassembled versions, they are simply exchanged as a whole.


The front fork of the bicycle is a multifunctional detail that determines pedaling comfort. The most important factors are the damping properties, the flexibility of the settings and the combination of bike type and riding style. Timely replacement of parts will extend the life of the mechanism, so it should not be neglected.

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