How to straighten a brake disc on a bicycle

About service

Disc brakes need extra care. It is important to monitor their cleanliness and promptly clean them of accumulated dirt. If this maintenance is neglected, the sand will cause a grinding noise during braking, it can also lead to damage to the components of the brake system.

Additionally, watch out for the n shape of the disc. In case of deformations, it is recommended to immediately repair this component. A curved disc not only causes a grinding noise during travel, but also reduces the safety of the vehicle.

straighten, brake, disc, bicycle

“Resuscitation” of brake pads

When servicing the brake system, it is necessary to assess the current condition of the pads. In case of problems with these components, you can perform their “resuscitation”. But this is a temporary solution, which allows you to use the braking system for a certain period. Sooner or later, worn out parts will still have to be replaced.

To carry out “resuscitation” of the pads you will need:

Sequence of operations:

How To True A Disc Brake Rotor On Your Bike

  • Pour fuel into the spirit lamp and set it on fire. Keep a cap nearby to quickly extinguish it when needed.
  • The pads must first be removed. Clamp them in pliers, hold over the fire with the abrasive side.
  • Put out the spirit lamp. The pads need to be cooled, wait until their temperature drops to room temperature.
  • Take the parts in your hands and use sandpaper to sand the abrasive side to achieve an even surface.
  • The components can now be put back into the brake system and continue to use them.

How to straighten a brake disc on a bicycle

The braking system is one of the basic components of any bicycle. As the name suggests, it is used to brake the bike. With the help of this system, it is possible to quickly slow down and stop the bike.

In general, there are several types of brakes for large:

  • Roller.
  • Mutual.
  • Stirrups.
  • Pedals.
  • Disk.

Disc brakes are a fairly common solution. They are divided into two categories. hydraulic, in which the force is transmitted through the hydraulic line, and mechanical, with a special cable. From the name it is clear that the main component of such a system is a disc, which is used when braking a bicycle.

Practice shows that it is the disc that is most often damaged during operation. It can be bent when using a bike, and let’s list the probable causes of such a defect:

  • Low quality. Cheap bicycles are equipped with braking systems with discs made of incomprehensible alloys. They clearly do not differ in strength, bend under any lateral loads and fail.
  • Sloppy handling of the great. The reason for the deformation of this component can be the inexperience of the cyclist and driving errors.
  • Bike fall and severe lateral loads.
  • Some bicycles come with deformed rims straight from the factory. This fact indicates the poor quality of the bike and the lack of proper manufacturing control. Be sure to check the health of all components when buying a vehicle.

The main advice for cyclists is not to buy cheap bicycles from no-name manufacturers. As a rule, small Chinese companies use not the best components in their manufacture. Deformation of the brake disc is the smallest problem that can be encountered during the operation of such a cheap bike.

Ways to solve the problem

There are several ways to fix this problem. You may have pressed the brake lever and the pads have moved to the disc. In this case, you will need:

  • Dismantle the caliper.
  • Choose a suitable tool and use it to move the pads.
  • Perform this operation carefully so as not to damage the components.

The second option is suitable for mechanical disc brakes. It can be used as a temporary solution to continue using the bike. But in the future, you need to carry out a full service, replace the failed components.

  • Take a hexagon.
  • With its help, move the pads apart, increase the gap between them.
  • Now you can continue driving.

This method is suitable for field repairs. It must be understood that it does not solve the problem of a bent disc. But on the other hand, it is possible to get rid of unpleasant sounds and get home to perform a full service.

Another temporary solution is to adjust the position of the caliper. If you can’t straighten the disc, and there is no way to put the bike in for repair, then you can use a similar method. But keep in mind that in the future you need to attend to the replacement of the deformed component in order to ensure safe travel.

  • Take the tool and loosen the two bolts that are used to secure the caliper.
  • Press it against one of the pads.
  • Adjust the caliper so that the disc does not come into contact with the pads.

The best solution is to fix the disc and remove deformations. It is recommended to use a specialized tool to perform such an operation. But it is not always possible to purchase such equipment, so you can use a conventional adjustable wrench.

  • Flip the bike.
  • Find the warp place on the disk.
  • Spin the wheel half a turn.
  • In the place where the disc is bent, move it to the opposite side.
  • Keep fixing until you get the desired result.

Eliminating play in mechanical disc brakes

You can get rid of the gap in mechanical disc brakes using the fifth hex when performing recovery procedures. In addition, you will need to involve another person in the work to press the brake lever.

How to True a Bicycle Disc Brake Rotor

Consider the main stages of pads straightening:

  • Loosen the bolts that connect the caliper to the adapter.
  • Press the brake lever firmly.
  • The pads will press against the disc and the caliper will move to the desired position.
  • While holding the brake lever, rotate the caliper until the curvature is eliminated.
  • After completing the procedure, the gaps should completely disappear.

Important! If you yourself cannot perform maintenance and get rid of existing problems with the components of the brake system, then it is better to contact a specialist. Professionals will be able to carry out adjustments and repairs, and you will continue to fully use the bike.

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Disc Brakes: Never Make These 5 Mistakes

If you want your brakes to perform better and last longer, avoid these common mistakes. What’s the bad news about disc brakes? In fact, there is no bad news and no problems if you avoid these 5 mistakes that affect disc brakes on any bike.

Brake Disc Straightening Procedure

In order to straighten the brake disc, only an adjustable wrench is needed from the tools. The repair actions themselves are extremely simple: you need to turn the wheel more slowly and look where exactly the disc starts to beat a little to the side. Next, you need to clamp the disc itself from the end and gently straighten it in the right direction with an adjustable wrench.

Thus, it is necessary to straighten-bend the disc only in those places where the stiffener is in contact with its outer diameter.

2.Do not accidentally spill grease, degreaser or brake fluid on the disc or brake pads

In this case, a problem with stopping power is even more likely than when oil gets from the skin. If you do accidentally spill some grease or other liquid on the wheel, remove the wheel from the bike and thoroughly clean the wheel with isopropyl alcohol and a clean rag. If fluid gets on the brake pads, it is better to replace them. In principle, it is possible to preserve them by removing the top layer of the lining material, but often oil or liquid soaks all the material, and then constantly contaminates the disc, which will affect braking.

Bridging the gap in mechanical disc brakes

If you have a mechanical disc brake on your bike (the approach to hydraulics is somewhat different), then you can remove the gap, or rather, eliminate some curvature of the brake pads, by properly fixing the caliper. Provided that the possible curvature of the disk is preliminarily eliminated.

For repairs, you will need a fifth hexagon, as well as another person who will press the brake lever at the right time. The procedure is as follows:

  • loosen the mounting bolts on the caliper, which secure the latter to the adapter;
  • forcefully press the brake lever;
  • the pads will press against the disc and the caliper is shifted as needed, and the curvature is eliminated;
  • the caliper will need to be rotated in this position without releasing the brake lever. until there are no traces of curvature. Like this. And no gap!

And if the caliper does not have an adapter, then you will need a set of calibration washers and, again, a fifth hexagon for twisting the bolts (although on some brakes you can do without a key and twist the bolts directly by hand).

The bolts are twisted neatly on both sides of the caliper, and the pads are brought close to the disc. You will get a barely noticeable gap, which will not prevent the disk from spinning.

How brake discs are straightened?

Message opposite “23 Jul 2012, 23:21

How to set up hydraulic disc brakes

The reason for adjusting the hydraulics is the appearance of extraneous rustling and creaking sounds, as well as resistance to wheel movement. There is a simple test: if the pads cling to the rotor, then if you spin the suspended bicycle wheel, it will stop quickly.

The adjustment procedure for the hydraulic system of the bike is as follows.

  • Loosen the caliper bolts so that it becomes movable;
  • Squeeze the brake lever on the bike to press the pads against the disc;
  • Check the position of the pad valves. It is important that they are symmetrically positioned with respect to the rotor;
  • Tighten the screws on the caliper without releasing the brake lever;
  • The last step: release the handle and check the correct operation of the bicycle brake system. It is necessary that the distance of the pads from the rotor corresponds to the thickness of the hair. In this case, the disc and pads should not be in contact with each other;
  • If the distance of the pads from the disc is different (in this case, the position of the disc itself is ideal), then do this. To adjust, press the rotor against the more protruding pad and bleed the brake lever ten times. It is advisable to perform this action with an assistant. One presses the disc brake pads to the rotor, the other gets to bleed the handle;
  • Using the adjusting hex, set the brake lever correctly.

Re: How to straighten brake discs?

Post Round »23 Jul 2012, 23:36

Install new pads if necessary

The brake pads are usually removed from the bottom, and for this you need to remove the wheel to pull out the rotor. For hydraulic brakes, insert a screwdriver or mounting paddle between the old pads, then slide them apart until they are against the caliper. Mechanical disc brake pads are often held in place by magnets. The Shimano caliper mounts the pads from the top. Pull out the split pin with platypuses, or if there is a threaded rod, unscrew it with a 3 or 4mm socket wrench. The pads are pulled out together with the spreading spring. Clean the adhered dirt from the caliper before inserting new pads and ideally install a new spring.

Hydraulic disc brakes

Mechanical disc brakes

Rinse so it doesn’t squeak

Brake fluid and cleaning agents are corrosive enough that you need to protect your hands and avoid getting these fluids on painted areas. We have found Muc-Off Disc Brake Cleaner to be most effective in reducing noise and improving performance. Too rough a rotor with a rough surface must first be made more polished with medium grit sandpaper. Sprinkle plenty of cleaner on the brakes (as shown in the picture) and let dry. Now check brake operation and repeat flushing if necessary. Environmentally conscious people can use ecological liquid to rinse with water, then rinse with clean water.

How to set up hydraulic disc brakes

The reason for adjusting the hydraulics is the appearance of extraneous rustling and creaking sounds, as well as resistance to wheel movement. There is a simple test: if the pads cling to the rotor, then if you spin the suspended bicycle wheel, it will stop quickly.

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The adjustment procedure for the hydraulic system of the bike is as follows.

Pump the brakes

When air enters the hydraulic braking system, it causes the brake lever to be gently applied all the way to the steering wheel. This step applies mainly to Shimano, Hope and Tektro brakes, which have a regular expansion tank and a standard bleed tip as shown. Wear protective gloves. Pull the drain hose over the drain nipple and secure with a tie. Place the bottle below the drain hole. Unscrew all of the rotor pads gripping torque settings, then depress the brake lever four to five times and stop with the lever depressed. Open the drain valve with a small open-end wrench (6 or 7 mm) and watch for bubbles in the liquid as it flows into the tube. Tighten the valve, release the handle. Repeat this operation 5-10 times, the expansion tank on the steering wheel must always be full. Continue until, after opening the valve, bubbles stop appearing in the fluid and the handle becomes stiff when pressed.

How to set up mechanical disc brakes

It is necessary to adjust the brake system of the bike when there is strong mutual friction between the disc and the pads, and also if the braking quality of the bike has deteriorated. The procedure is as follows.

If everything is done correctly, an ideal interposition of the pads with the rotor is obtained, without a hint of any misalignment.

How to set up hydraulic disc brakes

The reason for adjusting the hydraulics is the appearance of extraneous rustling and creaking sounds, as well as resistance to wheel movement. There is a simple test: if the pads cling to the rotor, then if you spin the suspended bicycle wheel, it will stop quickly.

The adjustment procedure for the hydraulic system of the bike is as follows.

  • Loosen the caliper bolts so that it becomes movable;
  • Squeeze the brake lever on the bike to press the pads against the disc;
  • Check the position of the pad valves. It is important that they are symmetrically positioned with respect to the rotor;
  • Tighten the screws on the caliper without releasing the brake lever;
  • The last step: release the handle and check the correct operation of the bicycle brake system. It is necessary that the distance of the pads from the rotor corresponds to the thickness of the hair. In this case, the disc and pads should not be in contact with each other;
  • If the distance of the pads from the disc is different (in this case, the position of the disc itself is ideal), then do this. To adjust, press the rotor against the more protruding pad and bleed the brake lever ten times. It is advisable to perform this action with an assistant. One presses the disc brake pads to the rotor, the other gets to bleed the handle;
  • Using the adjusting hex, set the brake lever correctly.

How to make the adjustment yourself?

Usually, brake adjustment on a bicycle consists in positioning the brake pads at the required distance in relation to the rim or disc, while maintaining their strict symmetry relative to the plane of the same disc. In addition, there will be a need to tighten the cable or adjust the brake lever.

So what exactly do you need to do to check and adjust the brakes? Let’s try to figure it out:

That’s all, the general setting of the brake system is completed here. This is followed by a deeper setting, which differs depending on which brakes are installed on your bike. This is because disc and rim brakes are equipped with different types of pads and different rotating parts.

Rinse so it doesn’t squeak

Brake fluid and cleaning agents are corrosive enough that you need to protect your hands and avoid getting these fluids on painted areas. We have found Muc-Off Disc Brake Cleaner to be most effective in reducing noise and improving performance. Too rough a rotor with a rough surface must first be made more polished with medium grit sandpaper. Sprinkle plenty of cleaner on the brakes (as shown in the picture) and let dry. Now check brake operation and repeat flushing if necessary. Environmentally conscious people can use ecological liquid to rinse with water, then rinse with clean water.

Install new pads if necessary

The brake pads are usually removed from the bottom, and for this you need to remove the wheel to pull out the rotor. For hydraulic brakes, insert a screwdriver or mounting paddle between the old pads, then slide them apart until they are against the caliper. Mechanical disc brake pads are often held in place by magnets. The Shimano caliper mounts the pads from the top. Pull out the split pin with platypuses, or if there is a threaded rod, unscrew it with a 3 or 4mm socket wrench. The pads are pulled out together with the spreading spring. Clean the adhered dirt from the caliper before inserting new pads and ideally install a new spring.

Customization

The principle of operation of rim brakes is clear, I think to everyone. 2 brake pads located opposite each other parallel to the wheel, between them there is a rim. When you press the brake lever, the pads compress the rim, stopping the wheel. The mechanism is driven by a cable pull.

In order for the brakes to work without failures, you need to monitor the integrity of the cable. If its braid is loose somewhere or at least one fiber breaks, the cable should be replaced. It is important that the cable runs freely in the shirt. And make sure that you do not have

The basis for good brake performance is the correct pressure of the brake pads against the wheel rim. This is regulated by the pad fasteners, which consists of a set of aluminum spacers and a nut on the axle. This kit allows you to fix the last at the desired angle. And to do this, you need to loosen the nut on each pad and firmly clamp the brake. Position the pads so that they are horizontal, touching the rim with their entire surface, but not touching the tire (see picture). And carefully shade the nuts without knocking out the position of the pads. This is true for cartridge pads. For ordinary pads, you need to press the rear of the pads horizontally to the rim first (see below)

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In addition, you need to watch that the brake levers converge in the same way. This is adjusted by the Phillips spring tension screw at the base of the lever.

If when you press the brakes one lever moves weakly, then the screw on this lever should be tightened a little, too easy. unscrew.

When set up correctly, v-brakes will perform just as well, and some models even better than disc brakes! The design features of the v-brakes allow adjusting the pads in almost any plane, but this is not possible with caliper rim brakes. The price of rim brakes is significantly less than that of disc brakes, they weigh less and are easier to adjust than disc brakes

The pads should be replaced with new ones when their braking surface is erased to the level of the grooves for the drain of dirt, that is, when the working surface becomes completely flat. And if the pads are worn out on only one side, this means that they were installed incorrectly, and they will also need to be replaced.

First, loosen the screw holding the cable.

The main thing when installing a conventional brake shoe is to put on in the correct sequence all the washers and gaskets that make up their fasteners. Also note that some models of pads can be divided into left and right, this is indicated on the pads themselves, take this into account when installing.

Replacing cartridge pads is even easier. They have a metal base and only the rubber pad needs to be replaced. There is a locking cotter pin on such pads (do not lose it), you need to pull it out and slide out the rubber pad. Then insert new pads and secure with a cotter pin. When installing the trims, pay attention to the indicators for the right and left side.

After replacing the pads, screw the adjusting drum on the brake lever fully and unscrew it one turn. Squeeze the brake levers with your fingers, reinstall the cable and secure with the screw. The distance from the wheel rim to the shoes should be 2 mm.

Rim brakes have a very simple principle of operation. two brake pads installed opposite each other and parallel to the wheel, and between them the rim Pressing the brake lever force through a system of cables and shirts. transmitted to the brake levers, which press the pads against the wheel rim, stopping it.

For smooth operation of the rim brakes, you need to monitor the integrity of the cable and the absence of “eights” on the wheel. If at least one fiber breaks on the cable, it must be replaced. The cable should move freely in the shirt and if it gets stuck it is necessary to change either the cable or the shirt.

The main thing in the high-quality operation of rim brakes is the high-quality pressing of the pads to the rim. This can be adjusted by fastening the pads. The fastener consists of a set of washers, gaskets and a nut, it allows you to fix the shoe at the desired angle.

To adjust, loosen the nut on each shoe slightly so that the shoe can be moved with your fingers, but it will not move. Place the block parallel to the wheel rim, note that it must not touch the tire (the distance between the block and the tire must be at least 1 mm.).

  • If you have soft rubber brake pads, they will deform when braking. Therefore, they must be installed so that the leading edge of these pads is 1 mm. closer to the rim than the rear. For this, a 1-1.5 mm thick gasket must be placed under the rear parts of the pads before adjusting. For example, a piece of rubber cut from a worn bicycle tube.
  • If you have brake pads with a rigid base that do not deform when braking, you must install strictly parallel to the rim.

Then look at the brake levers. Squeeze and release the brake levers several times, the levers should converge and diverge equally. This can be adjusted with the spring tension screws located at the base of the lever. We turn the adjusting screw on the lever that deflects too little, and unscrew it if the lever deflects too much.

In order to remove the wheel, you do not need to unscrew the brake cable, you just need to release it from the clamp. To do this, squeeze the brake levers with your hands and remove the rigid part of the cable jacket from the slot.

How to self-adjust your brakes to improve performance.

Adjustment is most often required when the brake pads are noticeably worn or after replacing them with new ones.

This procedure is not complicated and everyone can do it.

Required tools.

  • Adjustable wrench
  • Platypuses
  • Screwdriver
  • Rotor cleaner such as Muc-Off
  • Emery or medium grit sandpaper
  • Socket wrench set
  • Brake fluid
  • Plastic bottle
  • Fuel or vacuum hose
  • Protective clothing (gloves, goggles)
  • Cable ties
  • Socket, open-end wrenches for 6, 7, 8mm
  • 10 step guide to setting up your brakes

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