How much oil to pour into the bike fork

Bicycle fork maintenance

often, bike owners have a question with the choice of a good lubricant, because the quality and reliability of the fork depends on its properties. The most recommended in terms of quality are 2 types of grease:

  • Teflon, also available as aerosol Silicone

You can prolong the preservation of the purity of your oil by wiping the feet of the forks in the area near the oil seals after each ride.

From the article “How to choose a bicycle fork?”, We learned that there are several types of forks, and the care of each of these types is significantly different.

Maintenance of the spring-elastomer mechanism of a bicycle fork.

Maintenance of this type of forks is based on regular oil changes. With active daily driving, the fork requires an oil change several times per season. Oil is poured under the boot with a syringe, then the fork is developed. And the remaining oil is removed.

Maintenance of oil and spring-oil mechanisms.

An oil cartridge is located in one of the legs of this type of forks, which serves as a damper. Every 50 km, an oil and rubber band change is required. Timely replacement of oil and oil seals can significantly extend the life of this type of forks and avoid costly repairs.

Maintenance of the elastomer in such forks is not required, but the oil change should be made not only in the fork itself, but also in the damper.

Maintenance of air and air-oil mechanisms of the fork.

RockShox Fork. Full Rebuild. How To Service Upper And Lower Legs. Tutorial

The process of changing the oil in such forks is similar to caring for oil forks, but it requires special skills when parsing, because before filling the oil, you will have to bleed air and do many other manipulations. This is due to the presence of not only a damper in the forks, but also a chamber with compressed air.

Without going into details, let’s say that modern forks are a “pipe in pipe” design. Between these pipes there is a spacer (bushing) that reduces the play between the pipes and reduces friction allowing them to slide into each other. All this is abundantly lubricated with oil, and is closed from the environment with oil seals and anthers. Also, next to the oil seals and anthers, there may be a foam rubber ring soaked in oil. This allows for more bushing lubrication and less friction.

Fork maintenance

In addition to a routine inspection, the fork also requires regular maintenance, namely:

  • every 100-150 km of the distance traveled, it is necessary to clean and lubricate the feet on the oil seals;
  • every 500-1000 km. disassembly and full lubrication of oil seals;
  • every 4000-5000 km or at least once a year an oil change is made (applies to oil plugs)

In general, a bicycle fork should be lubricated at least once a season, however, if you are actively using your bike, this procedure is recommended to be done more often. If we consider a spring-elastomer fork as an example, the lubrication process will look like this:

  • Using a syringe, oil is poured under the boot.
  • For the lubricant to be evenly distributed, the fork must be designed.
  • Remaining oil must be removed with a soft cloth.

According to experts, it is better to use silicone and transparent greases as a lubricant.

In addition to lubrication, maintaining a bicycle fork also includes keeping the devices clean. To exclude the possibility of dirt getting into the oil and malfunction of the bike after each walk, you need to wipe the legs of the forks near the anthers.

Also, the bike fork can be adjusted by sag or rebound (if available). However, as experts note, this procedure should be performed in stages: after changing each parameter, you should check the progress of the bike. Otherwise, the rider may miss out on the difference in travel, and the effect of fork adjustment will be blurred. It is worth noting that the masters advise to start adjusting this device from the neutral position, in which the rebound should be set halfway, and the compression arrows are unscrewed completely counterclockwise.

How and how can you lubricate a bicycle suspension fork

I use Litol-24 grease to lubricate all of the bike’s front fork assemblies, including both the shock absorber and the head tube bearings. It is believed that it negatively affects aluminum parts when exposed to moisture. But using it for five seasons, no negative consequences were noticed. The advantages of this grease include good temperature resistance. It does not thicken both in severe frost down to.50 C and in extreme heat (up to 150 C).

Many people advise pouring liquid machine oils, sewing machine oil, and others into their forks. Personally, in my experience, a deterioration in the operation of the fork shock absorber was noticed (jerks were observed during compression and rebound of the spring). And if liquid oils worked better, manufacturers would have filled them in initially, which they do not.

We figured out how to lubricate the bicycle fork. Next, let’s see how to do this. We apply grease to the spring with excess (we ram the lubricant between the spring rings), the excess will come out through the hole under the stem and, if there is an excess in the pants, it will be squeezed out through the stuffing box seals (but you shouldn’t overdo it either). We also apply grease to the grooves of the cuffs and add forks to the pants. We lubricate all rubbing parts with a thin layer.

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Before installing the plug into the glass, do not forget to lubricate the bearings, rings and cups.

This completes the lubrication process and you can go back to assembling and installing the bicycle fork.

Why remove and disassemble the bike fork

A bicycle fork, like all other components, can be replaced, repaired or serviced. Therefore, before proceeding with these procedures, we need to remove it from the bike, and in some cases disassemble the shock absorber for parts. In what cases will we have to remove it? First of all, this is when it is replaced by another. Secondly, it may be necessary to replace bearings and / or support cups, apply new lubricant, and also, there are times when it is necessary to align the steering tube or perform other repair work.

Disassembling a fork shock absorber is most often necessary to replace lubricant or worn components. For example, these can be oil seals (cuffs), etc.

Fork routine inspection

Often, it is the prophylactic inspection of the fork that makes it possible to timely identify minor deviations from the norm in the operation of the device, and, accordingly, prevent a more serious breakdown. Typically, a visual inspection of the fork includes checking:

  • dropout states;
  • fork legs for dents, scuffs and other marks;
  • oil seals (anthers) for mechanical damage and oil leaks from under them;
  • pressure in air chambers;
  • the presence and condition of the lateral backlash of the legs in the “pants”;
  • the condition of the fastening bolts under the “pants” of the fork and adjustment knobs.

Bike Repair: How To Care For Your Fork

Like all equipment. the bike loves lubrication and caress, where it is needed. How often have you seen cyclists who ooze oil from the fork and bare metal peeking out from under the anodized legs? Believe me, there are such people. Without leaving, sooner or later, any part will become unusable. Today we will not talk about how to sort out the plug, but we will cover the issue of maintaining the plug in working order. And even if you have some kind of budget fork, timely care can significantly improve its performance.

motorcycles and motorcyclists

The knock in the front fork was already a little fed up to me and I decided to get rid of it all the same. Dismantled, washed everything. To get rid of knocks, I decided to install a rebound spring. I do not know what it is from, but it was long and it was enough for me for 4 blanks. I screwed it onto the fork like the rings from the key chains are screwed onto the keys. I trimmed it on the fork with pliers. I measured the length of the resulting spring with a caliper and cut the main springs by exactly the same amount. IMPORTANT! measure the length of the spring after putting the spring on the stem and not before. Since the spring after installation is slightly deformed and the length may not match.

My fork oil seals were leaking and having learned from past mistakes I did not change the fork bushings there was a slight backlash in them, but I think they are still similar. Replaced the cups of the plug assembly with oil seals. I decided to collect forks without covers. I like it that way. I polished the fork pipes, otherwise they were all rusty. I had to make a new headlight mount, but more on that in another BZ.

Checking work

The most adequate assessment of the work done after reassembly is a ride on an updated motorcycle. It is not for nothing that they say that after changing the oil, a completely different technique turns out to be in the hands of a motorcyclist. The fork must be firm, firm, and not fall or be too stiff.

Repair start

Before starting repairs, place the motorcycle on a comfortable and secure stand so that the front wheel is free. Next, you need to remove the wheel, disconnect it from the brake mechanism. In some cases, it is also necessary to dismantle the wing or rudder.

It is worth starting with the “undermining” of the plugs of feathers. Not unscrewing, namely, changing the position of the lid by a quarter of a turn. Plugs are always made with decorative treatment, or chrome-plated. If you do not have a reliable and well-sized key at hand, you should not injure the plugs.

A little slippage, licking edges will instantly destroy the attractive look. Some craftsmen use fabric or thin rubber as a spacer. This method cannot exclude the appearance of scratches, even if you try very hard.

The closed plug will not only protect the cylinders from the ingress of dirt, but also prevent injury from the fired tensioned steel spring. After loosening the crosshead bolts, you need to smoothly get the fork. Before this procedure, you must have a container prepared to remove waste oil from the fork. Turn the fork over and drain the oil from the feathers. The color and consistency makes it clear why the plug was wadded or too hard.

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Changing the oil in the motorcycle fork

The most common front fork is the telescopic design. The so-called “telescopes” are on all Soviet-made boxer motorcycles and appeared in the distant 30s of the last century. During the period of constant improvement and refinement of the design, many manufacturers have gone their own way, making significant changes to a seemingly simple design. Changing the oil in the front fork of a motorcycle should take into account all the design features and the principle of operation of each specific vehicle model.

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The most widely produced motorcycle is a fork design that uses two tubes. One is made of steel, with a larger diameter. The second is chrome-plated, which is called the fork feather. Moving up and down with the steering wheel, there is a hydraulic valve inside for each side. The structure is reinforced with a powerful spring. Protection is implemented by installing anthers and oil seals. Changing the oil in the front fork of a motorcycle is done by pouring liquid directly into the cavity of a tube of a smaller diameter.

As a result of active movement, reacting to each bump or pit, the oil is the first to become unusable. This is due to the fact that all kinds of debris, small metal shavings, due to the friction of metal parts, begin to get into the liquid. Already after a year of active driving, a change in fork behavior can be observed. Following the oil, anthers with oil seals also deteriorate. They start to leak water, all kinds of pollutants. The oil absorbs them and ceases to function.

Changing the oil in the fork of a motorcycle can be simple if the manufacturer provides holes for draining and filling oil, and it can be difficult when a total repair or restoration of some elements is required.


In order to understand what kind of oil to fill in the front fork of a motorcycle, read the manual or instructions for your vehicle. This information is very important as the oil can have different densities. Therefore, the denser the oil, the harder the fork will behave. A rigid fork transmits more vibration, making driving less comfortable. However, the main advantage is that there is no strong impact and deformation of the fork if you catch a hole at high speed.

It will be necessary to very clearly fill in the oil to a certain level. There are two ways to do it right:

  • Measure the former level when removing the plug. this only works if there are no oil leaks or deformation of the glasses;
  • Fill in exactly the volume indicated in the manual.

An airy or overflowing plug will not work properly. In the first case, the motorcycle’s stroke will fail, in the second, the reaction to irregularities will be too noticeable. It is the oil level that determines the volume of the air gap, which interacts with the road. For expensive and sporty motorcycles, it is important to know what kind of oil to put in the front fork of the motorcycle. It has a viscosity of 2.5. 3.5 and 7.5 W. It is noteworthy that by mixing two oils of different viscosities, you can get an average viscosity.

The remaining oil is removed by moving the piston up and down. If you see a significant excess of the resource by the color and contamination of the drained oil, it is necessary to rinse the inner surfaces with kerosene. Having filled in new oil to a previously determined level, you can proceed to reassembly.

pour, bike, fork

Important! If you have already disassembled the plug, immediately check all the elements for scuffs, damage. A caring motorcyclist immediately changes all anthers and oil seals to prevent them from leaking in the future, so immediately take care of the availability of spare parts. Particular attention should be paid to inspecting the bushings, which should fix the fork and not interfere with the operation of the seals. Often, a broken bushing gives freedom to the seals and anthers, which wear out quickly. An inexperienced motorist changes the anthers at regular intervals, but does not eliminate the cause of their wear.

What kind of oil to pour into the front fork Izh Jupiter 5

Rebound speed

This parameter will show how quickly the suspension returns to its original position after compression. How the bike can react to the next obstacle depends on this. The responsiveness of the rebound at high speed must be instantaneous so that the shock absorber has time to readjust for the next obstacle. It must be configured in such a way that the impacts received are extinguished earlier than they hit the bicycle handlebars. If the rebound speed feels insufficient, then you should start adding it with small values. Gradually bringing to ideal working conditions. It should be borne in mind that its speed depends on the thickness of the oil. Therefore, in cold periods, the rebound will be slightly delayed.

In expensive bike models, this indicator can be changed at any half of the stroke. This property is useful for extreme sports, especially for downhill, where riding involves many obstacles.

Adjusting the bike front fork and changing the fork oil

There are rigid bike forks and shock absorbers. The first ones are installed on high-speed road, triathlon, comfortable walking and cheap mountain models. They do not absorb energy while driving. To install them, you do not need to spend energy on the buildup. But such a bike fork is very uncomfortable when riding aggressively over rough terrain. It does not soften the unevenness of the road and transfers all vibrations from the surface to the steering wheel, so the rider’s hands get tired faster. And also the handling of the bike suffers, which can lead to a fall from it. Because of these shortcomings, a suspension fork is installed in off-road models. Its device is given in the article. For a comfortable ride, such a suspension must initially be properly adjusted and then lubricated regularly.

Fork setting

Suspension performance depends on correct suspension adjustment. It is influenced by the rider’s weight, the track and the chosen riding style.

Fork oil level | How to get it right

  • the initial load (SAG) is set;
  • the speed of the rebound is adjusted;
  • the compression speed is being debugged.

The main thing to remember is that you only need to change one parameter at a time. After a positive result, you can change the next setting. If you perform all the actions at once, you will not be able to find your way around, which has improved or worsened the fork’s performance. The configuration process may fail. Then it will be necessary to return everything to its original state (half-adjust the rebound and also the compression), and then start all over again.

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Your bike‘s fork alignment is largely dependent on the impeccably set preload. It will prevent the suspension from sagging due to the rider’s weight. Seg dampens shocks from bumps in the road and protects against loss of control over the bike. At a low degree, the suspension will become stiff, there will not be enough travel in it. This will cause the bike to lose contact with the surface. A large shog will require a lot of effort from the cyclist, and when descending, the fork will compress. And this will affect the comfort of pedaling.

The amount of load will depend on riding style, but will generally range from 20 to 30% of the full travel of the fork. For the convenience of adjusting it, manufacturers have provided a ring (rubber or plastic), and if it is not there, then a disposable flagellum should be attached to the leg. The way to change the sega depends on the type of plug:

  • in spring ones with an auxiliary chamber, they regulate the compression of air in it. In special cases, the spring itself is changed;
  • in air, its required value is achieved by changing the pressure in the positive sector;
  • in spring suspensions, it is regulated externally. Gradually changing the shog in small amounts. There are several types of springs on the market that differ in their rigidity. To increase the value of the load, it is necessary to replace the spring with a more rigid one, and to decrease it, vice versa.

You can find the right shog while sitting on a bicycle. If there is no special ring, then a plastic tie must be put on the fork leg near the oil seal. Then you need to sit on the bike and slightly press it to the ground, simulating by this action the force directed to the steering wheel while driving. The fork will push through. this will be the shog. Its value is determined by the shifted clamp.

Servicing Lubricated Fork Parts

In oil forks, oil acts as a damper. When the suspension moves downward, it flows through the inner valve. Returning back, she closes the valve. And the lubricant flows through small holes in it. It dissipates the thermal energy received from the compressed spring.

  • Open bath. Valves are installed on both sides of the fork and oil is present in the two legs of the fork.
  • Half bath. Grease does not leak into the pants and is only present in one leg of the suspension to keep the suspension valve running.
  • Closed type. In addition to the damper, made in the form of a one-piece cartridge, there is also a mechanism that blocks the damping.

In the first two types, the fork is moved, the lubricant and O-rings of pistons, springs, and oil seals are replaced. The fork legs and anthers are cleaned from dirt. Then the fork oil is poured. Some people use a thick lubricant, but it is inferior to the oil analogue in fluidity. Synthetics are mainly used: in a damper with a viscosity of 5 W, and in pants. 15 W. But semisynthetics and mineral analogs can also be used. The thinner their composition, the better it envelops the details. In cold weather, oil grease tends to thicken, therefore, in the off-season, preference is given to its more liquid consistency than in warm periods. On forks with an open damper type, the progression at the end of the travel is controlled by the oil level. The grease must be changed regularly to avoid breakage of parts due to hardening and friction.


Determines the amount of oil required to turn a bicycle wheel. Adjusts the compression speed of the suspension. There are three types of it:

  • low speed. It starts working at the beginning of the turn. Mutes and smoothes unevenness. Unlike rebound, this compression is responsible for the softness of the obstacle passing, and not for the speed of response. It can be used to increase the pedaling speed by increasing the stiffness or soften it for difficult trails with many bumps. It is involved in adjusting the fork sagging from the action of the bicycle brake on the front wheel. Adjustable from the unscrewed position;
  • high speed. Needed to change the progression at the end of the turn. She is responsible for the safety of the suspension when the bike lands. In some models, this indicator is adjusted directly at the manufacturer. If necessary, you can check its operation while pedaling. All according to the same yoke;
  • blocking. Compression at high speed in the closed position often goes into this state. This protection comes in handy on flat roads. For rough terrain, it is best to leave the suspension in working order.

Rarely, but still there is such a custom suspension protection as anti-breakdown. This is a kind of stiffness reserve that can be used at the end of the stroke. It protects the fork from kinking in the event of a strong impact. Its use limits suspension performance.

To enjoy riding with a mid to high end suspension fork, you must first set it up correctly. In budget models, there are practically no functions that could be adjusted, so they use the settings set at the factory.