DIY zoom bike fork repair

In detail: DIY repair of a bicycle fork zoom from a real master for the site my.housecope.com.

→ Pieces of iron and equipment → Vel.kom. Bicycle mechanic's notes # 3. Reviving and improving the Zoom fork.

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Nefelim
Bicycle workshop Vel.kom. Dikopoltseva 48
Inactive

Where: Centre
Registered: 21-04-2010
Posts: 5,600

The patient was admitted in a “colum” state, i.e. the plug did not work at all, everything was covered with sandy-solid filth, and it smelled quite unpleasantly of waste oil products. Can this miracle of the bike industry be made to work? The answer is below.

But first it had to be taken apart. It turned out to be quite a challenge. The pants are connected to the legs through long bolts and springs, the bolts themselves are located inside the leg, at a depth of about 25-30 cm. The car market on the industrial market helped with extension cords and a 5 mm hex head. Only the leg was filled with dirty grease by a few centimeters, and it was not so easy to hit the bolt head with a hexagon, but it was still possible. Having unscrewed both bolts and pulled out the legs from the pants, we look at the guts of this miracle of engineering thought.

Before cleaning:

After cleaning:

Inside we find:
- two springs are rusty.
- four plastic plugs for the ends of the springs
- two rubber bumpers for bolt heads
- a 4 cm rubber bump stop located inside the spring and probably serves to reduce the travel of the fork. (Actually not) THE MOST IMPORTANT DETAIL.
- two connecting long bolts
- pants - a rawhide piece of foil, plays in the hands like a tin can.
- legs - a steel monolithic part capable of rivaling the strength of the Nokia 3310

Video (click to play).

This is not Fox F32 Evo CTD. =)

Putting on gloves to the elbows, we begin to scribble shit from everywhere, from the legs, from the pants, from the springs. They are cleaned exceptionally crappy, a lot of rags are gone. There is even more time. After mechanical cleaning, everything is rinsed with cleaning agents in hot water, wiped and dried. By the way, the coating from the working surface of the legs has been safely erased, which means that once the fork still worked. The surface itself, even without paint, is quite smooth, without roughness and irregularities, not a little passable by "zero" to fill up the irregularities, and give hope for the fork's work in the future.

Let's start assembling. But first, let's "pump" the fork a little, increasing its travel. To do this, take the four-centimeter rubber boss described above, and cut it into three parts, 1.33 centimeters each. Fuck one of them. Insert the other two inside the springs, but not into one, but into each one, one at a time. Thus, when the fork breaks through, no metallic sound will be heard and the fork travel will increase from 60 to 86 mm. This is very, very good.

We assemble the structure, lubricating all parts with normal grease in the process. There should be enough of it, but not too much, so that it does not squeeze out during operation, and it does not collect dirt on itself. We pay attention to the stuffing box-anthers (it is not entirely clear what it actually is), there is a cavity inside them, we fill it generously with grease. After assembly, we wipe off all the external elements, remove excess grease, and see what happened.

The fork honestly fulfills its new 86 mm of travel, and even with a slight progression at the end due to the rather stiff springs. Of course not about any compression, rebound, etc. Needless to say, the work is extremely linear and dull. You won't be able to configure anything either. But let me remind you that this is a fork from a segment in which the components are not required to work at all. So I think the result is satisfactory.

I am waiting for the answer from the owner of the fork, I wonder what the impressions will be.

And finally, I will say a little "wisdom". Expensive and cool components are great, but with proper care and maintenance, even the simplest pieces of iron can often be brought into working order so that they can efficiently perform their tasks. Even on Auchan, the forks can work the brakes, brake and switch the switches. Especially if there is no possibility / desire to buy forks for 50k, brakes for 20k, switches for 10k.

A bicycle fork serves more than just a link between the frame and the front wheel. On MTB models, it also serves as the main shock absorber, smoothing vibrations, stress on the arms and negative effects on the mechanisms and the frame. Like any mechanism, it requires periodic maintenance, adjustment and replacement of component parts. And all this will require removal and disassembly. Is it possible to disassemble the bike fork by yourself? Quite, it only takes a little time, a few simple tools and accuracy.

Obviously, there is no need to simply dismantle it from the bike. There are a number of reasons for this - replacement, overhaul and service. Replacement means removing an unusable part and installing a new one instead.

Repair - partial replacement of components. These can be bearings, washers, spring, damper or oil seal. Service includes adjustment, cleaning, lubrication.

The main symptoms that indicate removing the fork from the bike and tidying it up are:

knocking on the go;
the fork is stuck and not adjustable;
bearing wear;
lack of lubrication (creaks);
cranking, heavy steering;
cracks in the legs and pants.

The device of the classic front shock absorption system is a metal spring and a rubber damper. Shrinkage of the spring and elongation of the elastomer rod degrade the properties of the shock absorber, making it stiffer. Regardless of the setting, the fork will knock on obstacles.

Backlash and tight handlebar travel indicate worn bearings and o-rings, as well as a dirty fork cavity. A suspicious creak when the bike is moving indicates that it is necessary to lubricate the part, and you cannot do without removing it.

Read also: Stinol 107 DIY repair

Any mechanical damage leads to unexpected breakdown of the system. If cracks are found on the body and legs, the fork should be replaced immediately with a new one!

In disassembling the shock absorber with your own hands, you will need tools:

Screwdriver Set;
flat sharp object;
wrenches + sliding;
hexagon;
small hammer.

When working, you will need to clean and lubricate the part again, so you will need a can of grease, a few soft rags and gloves.

And a few recommendations in the end:

check the bike fork for integrity every 500 - 1000 km;
clean the feet on the oil seals every 150 - 200 km of the track;
apply a little grease to the stuffing box of the legs several times a season;
specially for hydraulic shock absorbers - change the oil every 5000 km.

The first step is to get rid of the front wheel. To do this, turn the bike upside down. Release rim brakes by swinging out the clamping bow. With the discs, you can immediately start removing the wheel. Wings and other devices are immediately removed.

We put the bike in the usual position. Now you need to pull out the steering wheel and remove the plug from the glass:

1. Release the side bolts on the stem.

2. Completely unscrew the steering pin fasteners, or "anchor" bolt.

3. The steering wheel is carefully removed from the fork. You can immediately wipe the pipe with a soft cloth.

4. Use a thin sharp object (screwdriver or office knife) to pry the retaining metal washer over the glass.

Use the same tool to press out the gasket under the washer. As soon as the ring comes off the edge of the glass, gently pull it out with your hands.

5. Raise the frame and gently pull the fork out from below. Why? To avoid damaging or loosening the bearings.

6. Next, you need to separate the crown from the stem.To do this, it is necessary to knock out the connecting ring on which the steering column bearing rests.

Carefully use a thin sharp object and a hammer to separate the ring from the edge of the fork. This completes the removal process.

First, inspect the bearing ring. There should be no damage or broken edges on it. Otherwise, you will need to replace it (if an old plug is installed). Assembly sequence:

1. Put the ring on the joint of the fork with the steering column.

2. Grasp it with an adjustable wrench from above.

3. Using a hammer, press in the ring evenly with soft blows on the jaws of the wrench. We hammer "by sound": while he is deaf, we continue to press, sonorous - the ring has fallen into place.

4. Lubricate the surface of the stopper (grease - lithol-24, buksol or a special compound).

5. Carefully lay the bearing with the balls facing up. You can also put some lubricant on it. A sealing washer must be placed under the bearing.

6. Carefully insert the stem into the glass and repeat all removal operations in reverse order.

You don't need to disassemble a part to replace it, but its repair will require you to "fit" into the mechanism and delve into it thoroughly. Let's consider how to sort out a spring-elastomer type suspension fork:

Unscrew the bottom fasteners with a hex wrench.
Remove the spring compression adjustment bolt - Preload. It is the main damper travel regulator.
Remove the elastomer restrictor or damper.
Take off the "pants".
Using a screwdriver, remove the seals from the pants.

The main reasons why the fork squeaks, makes knocks and does not smooth out vibrations while the bike is moving include wear of parts, water and dirt ingress, lack of internal lubrication. We put in order:

Remove all dirt from the inside of the pants.
Wipe the fork legs, spring and seals thoroughly.
Replace the defective part if necessary.
Install the elastomeric damper (fill in oil through the nipple for the hydraulic fork).
Lubricate the inner cavity - inject oil from a can.
Install the retaining bolt and Preload.

This is how the bulkhead of a bicycle fork looks like with your own hands. Is it needed for a new part? There is an opinion that a plug that has been sorted out at once will be better tuned and will last longer. Much depends on the quality of the kit, but it will be found out in real riding conditions.

Scheduled repairs are done as needed, bulkhead once a season. And of course, you shouldn't forget about prevention. After each ride, remove dirt from the surface of the oil seals, lubricate, check the fasteners and integrity.

A mountain bike, and indeed almost any modern bicycle today is difficult to imagine without a shock absorption system designed to effectively and affordably increase the handling and ride comfort of this type of transport.

Most often, bicycles are equipped with a front suspension fork, thanks to which it is much easier for cyclists to overcome road bumps, even at high speeds, while the load on the palms and hands during the ride is minimal. By minimizing vibration, a well-matched and aligned fork can help extend the life of other bike components such as the frame and steering bearings.

The service life of the fork itself can be extended several times through proper care and regular maintenance.

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. Generally, 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 the adjustment knobs.

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 carried out 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.

Any residual 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 lubricating your bike fork, it also includes keeping the device clean. To exclude the possibility of dirt getting into the oil and malfunctioning 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 starting the adjustment of this device from the neutral position, in which the rebound should be set halfway, and the compression arrows are unscrewed completely counterclockwise.Work on changing the oil, foot oil seals, sealing parts, as well as on eliminating a malfunction of one of the components is accompanied by a complete or partial disassembly of the bicycle fork.First you need to turn the bike with the wheels up, and after releasing the brake (in the case of a rim brake), remove the front wheel. After that, you can remove the stem with the stem and the head tube.Then we remove directly the plug itself. It is important to ensure that the balls are not lost from the bearings when removing the fork. Any sharp object can be used to remove the tapered support ring from the fork stem. After that, you can start repairing or servicing the plug.Next, consider the procedure for disassembling the fork (a spring-electric fork will act as an example):

The lower fixing bolts are unscrewed using the hexagons.

Unscrew the Preload spring force adjustment bolt (it is important to remember the bolt stroke).

An elastomer is obtained, which is entrusted with the function of limiting the travel of the spring (sometimes, if necessary, you can change the size of the elastomer by cutting).

The bolts are unscrewed and the "pants" are taken out. In this case, you need to monitor what flows out of there (dirt, water, oil).

Anthers are taken from the "pants" with a screwdriver, as well as bosses, which for this need to be rotated around their axis.

Further, all components are checked for cracks or other damage and washed with kerosene. Items requiring lubrication are treated with an appropriate material. It is worth noting that it is better to lubricate the spring with a thick grease, which will increase the efficiency of the bicycle fork.

Unscrew the bolts securing the stem to the steering tube, and then unscrew the bicycle fork anchor bolt.

Carefully remove the steering wheel together with the stem and lower it down. At this stage, you should act carefully so as not to damage the hydraulic lines or accidentally hitting the metal parts of the steering wheel on the frame, so as not to scratch the latter.

Remove the spacer rings and the guide sleeve (cone). To do this, carefully pry it with a small flat screwdriver in the area of the cut. Then we take out the upper rolling ring and the upper bearing. All these actions are illustrated by the pictures below.

All operations have been completed and now you can carefully remove the steering tube from the glass. After that, it remains for us to get the bearing, the lower rolling ring and remove the front wheel. To do this, we loosen the eccentric or unscrew the fixing bolts (depending on the type of attachment). This completes the process of removing the bike fork.

After we have removed the suspension fork from the bike, old used grease should be removed from all of the above components, namely the bearings, cups and raceways, as well as the steering tube and other areas. It's not worth applying a new one yet, we will add it back to the glass at the stage of installing the fork.

Next, let's start disassembling the shock absorber for further lubrication replacement.

Turn the plug over and unscrew the mounting bolts.
We remove the pants from the legs of the fork. If necessary, remove the oil seals.
We remove used lubricant from all accessible surfaces. This procedure can be left for later and performed after complete disassembly, but it is preferable to do it right away in order to avoid oily marks on clothes, tools, etc. Do not forget to remove dirt and grease from the cuffs of the bicycle fork, as well as from the inside of the pants themselves.
Then remove the lower travel stops and stop stops. To do this, we apply a little effort and pull them off the rods.
We unscrew the adjustments on each of the fork legs. They are unscrewed using a special key, which, unfortunately, we did not have. Therefore, we had to make our own self-made key for these cases. We will attach a photo below, if it will come in handy to someone. We take out the springs with caps and elastomers, as well as two rods (one from each leg).
We remove the old grease from all surfaces of the fork.

This completes the process of disassembling the bicycle fork shock absorber. Next, apply new grease. We will consider what can be used as a lubricant below.

I use Litol-24 grease to lubricate all the components of the bicycle front fork, including both the shock absorber and the head tube bearings. It is believed that it negatively affects aluminum parts when moisture enters. 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 fill them in initially, which they don't.

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.

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.

The process of assembling and installing the bicycle suspension fork is carried out in the reverse order. The only thing that you should carefully and carefully perform this operation in order to avoid incorrect installation of components. After you have installed the assembled fork back on the bike, secured the stem, be sure to check that there is no play in the steering tube in the frame glass. If they are observed, then be sure to eliminate them before the trip.

After you set everything up and start riding, for the first time, there will be an abundant release of lubricant through the cuffs of the bicycle fork pants. Don't worry, this is normal. Over time, excess oil will be squeezed out, and this process will stop. During this period, don't be lazy and remember to wash off excess lubricant after each ride.

The frequency of changing the lubricant of a bicycle fork depends not least on the road surface on which you are riding. If your routes contain an abundance of dust, mud, sand and other abrasive material, then the frequency of service should be increased.Here we give the average figures after which maintenance should be performed.

Approximately every 700-800 km, the oil seals should be disassembled and lubricated, and every 4000-5000 km the entire fork is moved and lubricated.

Bicycle fork device.

The plug without fail requires:

cleaning and lubricating the feet on the oil seals - every 100-150 km of the distance traveled;
inspection for cracks in the "pants" of the plug, lubrication of oil seals with disassembly - every 500-1000 km;
for oil forks - oil changes annually or after 4000-5000 km of travel.

Among the tools necessary for working with a bicycle fork are a screwdriver, pliers, a wrench, a small adjustable gas wrench; taking into account the specifics of working with oil, it is advised to stock up on rags or rags, in addition, work can be performed with gloves to protect hands from damage and pollution.

To remove the plug from the bike for its subsequent maintenance or complete replacement, it is necessary to turn the bicycle upside down, release the brake (if it is a rim one) and remove the front wheel. At the second stage, the steering wheel with the stem is removed, then the steering tube.

After that, we remove the plug, it is extremely important not to lose the balls from the bearings. Then the support tapered ring is removed from the fork stem (usually using a sharp measure, gently squeezing it from all sides). Then we have a plug ready for service.

Individual users are advised to sort out even new, just purchased forks, explaining this by the need for individual debugging of the element.

How to disassemble a bicycle fork (using the example of a spring-electric fork) read below:

it is necessary to unscrew the lower mounting bolts using hexagons;

Preload spring force adjusting bolt.

This completes the fork disassembly process and begins the process of caring for the parts received: a thorough inspection of the elements for damage, cracks and other things is necessary, thoroughly rinse with kerosene and lubricate the elements that need it. It is important to lubricate the springs with heavy grease for best fork performance.

Assembling the plug runs in the reverse order of the parsing process and it is impractical to describe it additionally. The main thing is to carefully follow the order of the described procedures.

An untrained and inexperienced user is not recommended to carry out: if it is possible to cope with simple care, then it is better to leave such a procedure to a qualified specialist. As a last resort, carry out the replacement under the supervision of the master, following his recommendations.

Lubricate the bike fork it is necessary once a season, but with active use, this procedure may be required more often. The process of lubricating a spring-elastomer fork is extremely simple: oil is poured with a syringe under the boot, then the fork is developed, and the remaining lubricant is removed with a soft cloth. Teflon grease is best applied to the feet near the oil seals (aerosol grease is increasingly being used).

Among the best lubricants masters call silicone and transparent greases.

Equally important is keeping the fork clean: Be sure to wipe the fork legs near the boot boots after every bike ride to prevent dirt from getting into the oil and preventing the bike from working properly.

Adjusting the bike fork begins with setting the sag, then rebound (if its adjustment is provided), under which the low-speed and high-speed compression will be adjusted. Experts note that the adjustment should be carried out in stages: made one change - checked the progress of the bike with a walk, only then change the next parameter. If you do not adhere to this recommendation, then the owner risks missing out on the difference in travel and lubricating the effect of the fork adjustment.

ADVICE! You need to start the fork adjustment process from the neutral position: half the rebound, the compression arrows are unscrewed completely counterclockwise.

Of course, without the appropriate experience and skills in repairing bicycles, it is better not to take risks and turn to competent specialists. But over time, every cyclist who is more or less interested in his vehicle begins to understand the intricacies, remember the name of the parts and their functions, and feel the root of the problems. Therefore, over time, even such a difficult thing as repairing a plug can become an easy procedure.

Difficulties may arise due to the design features of the fork itself or its breakdown.

Usually, owners are divided into two types: some prefer to ride a bike until all systems fail and it will be impossible to save such a “patient”, others - carefully monitoring the condition of the bike and preventing any breakdowns.

When 9 out of 10 people say a shock absorber for a bicycle, they imagine a bicycle fork. They're partly right, but a fork is a front shock, while a bike might also have a rear shock. A bike equipped with front and rear shock absorbers is called two-suspension.

If unforeseen difficulties arise with the shock absorber, for example, a creak or other extraneous sounds, then it will be quite difficult to find the cause on your own. As a trial option, it is advised to lubricate it with silicone aerosol, but if the creak persists, then the reason is most likely deeper, and the bike needs to be examined by a master.