The connecting rod on the bike is unscrewed what to do


connecting, bike, unscrewed

Consider the principles of correct installation of connecting rods and the main problems that may arise during their running-in process. If it seems to you that the part is installed correctly and there are no complaints about its quality, then you should act by the method of elimination. First, you need to make sure that the connecting rods are not defective, but if it is found, then it is worth performing a warranty replacement. In a more difficult case, when everything is in order with the part, but it still continues to be unscrewed, you need to contact another installer. Despite the fact that such a decision may seem too radical to many, its influence among cyclists is very underestimated. After all, the cranks on a bicycle are corrected in space only by the installer, and some malfunctions may be the result of his negligence. Well, and the most categorical mounting option can be the use of a thread lock. The functioning of this glue for metal is expressed in the following: after applying a few drops on the surface, the parts twist and form a monolithic connection, which is very difficult to break. Cranks on a bicycle are no longer inconvenient, but removing them is much more difficult. This method is extremely radical and is usually only used in the field or in hasty troubleshooting, so it should be used with caution and foresight.

The basics

The reason for this malfunction most often lies in the manufacturing defect of the connecting rods or their improper installation with an offset relative to the axis of the carriage assembly. Although a defect may also form due to the fault of the manufacturer, this case is very rare, since during the production process the rejection of products is also carried out, which does not correspond to the quality parameters. While an acquired malfunction. due to significant wear or low qualification of the installer. is much more common. After all, it is enough to fix the connecting rods on a bicycle with a deviation from the vertical or eccentricity once, and the results will be disastrous. When the cyclist’s weight is applied, the splines will wrinkle, and in the case of the “square” mount, he will tend to the circle. Indeed, at the point of application of force, there are very significant loads, and they can disrupt the functioning of the entire mechanism. Therefore, the cranks on the bike must be installed reliably and correctly. Since only in this case, their fastening system will evenly distribute the axle load, and they will delight their owner with a long service life.

How the connecting rods are installed. It’s not that easy on a bike

Bicycle maintenance is not as easy as it might seem at first glance. Especially if it is carried out by a person who has no experience in performing repair work. Therefore, if your qualifications do not allow you to carry out maintenance of your “iron horse” on your own, you should contact professionals who can carry it out correctly. But if the final decision is made to carry out all the work with your own hands, or you, for example, unscrew a connecting rod on a bicycle, then you should understand the principles of the structure of your “iron friend”.

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If it is planned to service or replace the connecting rods on a bicycle, which is usually carried out during pre-sale preparation, cleaning or lubricating the entire system, then you need to stock up on a special tool. Removing this element from its seat is very difficult. It sticks to due to the forces of intermolecular interaction, therefore, the removal of the connecting rods is carried out with the application of significant efforts. To reduce them, special sprays (WD-40 or analogs) can be used, which facilitates the sliding of the element along the slots. A squeeze is used as a special tool for removing this unit. On one side, it is twisted into a special hole on the connecting rods, and on the opposite side, it is rotated with a wrench. The forces that must be applied to the tool must be uniform, since otherwise both the connecting rods and their carriage assembly can be damaged. The rod, which is located in the center of the squeeze, gradually squeezes the part out of its seat, and after a while the process can be considered complete.


The connecting rods are a very important structural element that is designed to transmit muscle forces by pulling or pressing on the pedal, which rotates the wheels through a chain drive system. And there is nothing worse for a cyclist than unscrewing their mount or even the backlash that occurs during movement. If the cranks on the bike are loose, then over time this malfunction can play a very bad joke with you. After all, this unit also holds the pedal, which plays the role of a stirrup for the rider, and its loss in the traffic flow can be very dangerous. If, while moving, the cyclist loses his fulcrum, then this affects his concentration and in the future can lead to disastrous consequences. a fall or even an accident.

In the process of work, it is necessary to follow these recommendations, which will simplify their implementation and finally close the question of how to remove the connecting rods on a bicycle with your own hands. This experience will be very useful for a beginner cyclist, as it will allow him to get acquainted with the basics of servicing his transport.

When the connecting rod is unscrewed

this is very bad. Cranks for a bicycle are a very important detail (however, there are practically no unimportant parts in the design). they are the lever that transfers the pressure / pulling energy of the pedal to the chain and sprocket system that ultimately turns the wheels. And if the connecting rods loosen and unscrew right on the go, this is not only unpleasant, but also dangerous. After all, the connecting rod not only transmits energy, but also holds the pedal, which plays a role similar to that of the stirrup for the rider. the support for the legs.

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In general, we found out: the connecting rods falling off are very bad. Now let’s move on to the reason for this disgrace. In general, the reasons may be different, but the common primary source is a defect in a part: axle or connecting rods. A defect can be a factory defect (a rare case), acquired from prolonged use (in short, wear), and acquired due to the excessive curvature of the collector’s handles. It is enough to not firmly fix the connecting rod on the axle once, and subsequent trips will begin to “eat” the splines at a curb pace or turn the axle square into a circle, depending on the type of carriage: square, octalink. There are very large forces involved. The fastener can be unscrewed both during pre-delivery, and you yourself when cleaning / lubricating / replacing the system. be careful.

So, getting to the topic of this post. Suppose it seems to you that all the equipment is normal, you twist everything as it should, but for some reason this infection continues to unscrew. The correct solution is to replace the parts, if it does not help, replace the assembler. But if such a solution seems too simple or you need to stretch a little more before the upgrade, then you can suffer. At bicycle forums, when it comes to spontaneous unscrewing of the connecting rods, they sometimes give very strange recommendations: put a razor blade if the axis of the system is “square”, wrap it with foil, relying on the effect of “cold welding”. Especially evil ones recommend welding the connecting rods to the axle Indeed, in this case they will not be unscrewed, but it will be possible to “remove” only with a grinder, and the method is applicable only to steel connecting rods. reasonable ones suggest using a thread lock. Actually, here we come to the point of publishing.

The thread lock (aka threadlock) is a special anaerobic compound that works like glue for metal. “Anaerobic” means that curing does not require oxygen. can take place inside the assembled threaded joint. A drop or two is applied to the thread, distributed when screwing (or after) and solidifies the threaded connection. With regard to the twisting rods, this means the following: if replacing parts for some reason is not an option for you now, the use of a thread lock may solve the problem. We clean the carriage axis, the inner surface of the connecting rod, the bolt thread (or nuts in the cheapest carriages) from traces of grease, collect as usual, before (or after. see below) tightening, apply a few drops of the retainer to the thread and tighten what there is foolishness.

How does the retainer work? It bonds together twisted parts, distributes the load along the entire length of the thread, prevents self-loosening and, in addition, protects against corrosion and rust.

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Now comes the fun part: retainers vary in scope and strength. So, I recommend that you read the instructions before use. For orientation, it is enough to know the following: the red retainer is the most durable (it can be problematic to disassemble the thread fastened by it), blue / blue. the average retaining force. There can also be green (weak or strong fixation. depending on the manufacturer), purple. “moderate”, violet. weak. Conclusion: if there is a choice, take the blue retainer, if there is no choice, any will do.

How To Inspect the Connecting Rod on a Dirt Bike

How to disassemble what is assembled with a thread lock? In theory, hand tools are enough. In practice, especially when using red clamps, the lever of the “hand tool” may require a very large one, with the stubborn resistance of the bolt, heating with a construction hairdryer or, if not, a lighter helps. Just make sure not to spoil anything unnecessary with the heat. When it cools down, the retainer may seize again, etc. do not waste time disassembling.

So, that’s all about the use of thread retainers for the case of unscrewing bicycle connecting rods.

Fortunately, the problem described above is quite rare and never occurs for most cyclists. Long live quality components and skillful assembly! Remember, in an amicable way, the thread lock should not be used when assembling the bike. If you need it, then something is wrong.

but there is a case when the thread lock will not help either. the carriage axis goes too deep into the connecting rod hole. In this case, the fixing bolt does not rest against the connecting rod, but against the carriage axis and, in fact, does not fix anything. Here the methods of “wrapping in foil”, “slipping a blade” are just justified, but they are not very aesthetic and “collective farm”. You can grind off the edge of the axle. By shortening it, we will provide the necessary distance for fixing the connecting rod with a bolt. But usually the axis is made of high-quality metal and you cannot grind it with a hand tool.

How to change motorcyle connecting rod kit crank.

An elegant solution would be to add a washer to the inside of the connecting rod. It will give the necessary additional couple of millimeters and will allow you to fix the connecting rod on the axle with a bolt. There are no ready-made washers of the required shape, but it is easy to obtain it by modifying the DIN 125 M10 washer with a file.

The outer diameter of 20mm corresponds to the hole in the connecting rod, and the inner diameter of 10mm is not difficult to bore to the size of the square axis.