How to disassemble a chainring wheel on a bicycle

Installing connecting rods

The key is cleaning all joint surfaces and generously coating them with grease. Firstly, this will make it easier and smoother to install the connecting rod, secondly, it will greatly facilitate its subsequent removal, and thirdly, it will eliminate one of the most common sources of mysterious crunches and creaks “somewhere in the carriage area”.
The connecting rod must be deeply seated on the shaft to prevent backlash, otherwise the seat will quickly fail. This is achieved by tightening the fastening bolts with a torque of 50-70 Nm, that is, with a very high force.

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Types of connecting rods and carriages

This is the OCTALINK standard. On carriages of this type, the axis has a circular cross-section, and there are 8 protrusions at the ends of the axis. Bicycles of this type are equipped with bicycles of the upper and middle price range. This type of crank is used on expensive mountain and road bikes. (in particular, for SHIMANO. on DEORE LX / XT and XTR equipment, although recently it is increasingly used in components of the middle price category) The connecting rods are attracted by a special hollow bolt, under an internal hexagon by 10, and are protected from the outside from dirt by anthers. The boot is simply screwed into the connecting rod. The carriage axis is hollow, and therefore traditional pullers do not work. they simply have nothing to rest on. It is necessary to use a special puller
This is a connecting rod of traditional design. This type of crank is used on mid-range bicycles. (for SHIMANO. on DEORE, ALIVIO, ACERA equipment). Although, OCTALINK has begun to be used on new equipment of these classes. The connecting rods are attracted by a screw, which is screwed into the axle. The screw has an 8 mm Allen key. A plastic boot is put on the screw
This kind of connecting rods is also common. It differs from the previous design only in that the screw attracting the connecting rod is located under the plug. the boot. The connecting rods are attracted by a bolt that is screwed into the axle. The bolt can be unscrewed with a spanner wrench 14. The end of the carriage axis is closed with a plastic boot. In this photo, the boot is removed.
This type of crank is often used on inexpensive bicycles. Here, the carriage axis also has square sections at the ends. But here the connecting rods are attracted not by the screw, but by the nut. The nut is usually located under the boot.

There are other types of connecting rods. For example, on the new SHIMANO equipment (in particular, the XTR2003 and SAINT groups), the carriage is made in the form of a monoblock, when the right connecting rod is structurally combined with the carriage axis. To service such a carriage and connecting rods, a special tool is required.

Connecting rods

Cranks are some of the most heavily stressed bike parts. On domestic road bicycles, they are made of steel, and on imported and sports bicycles. from aluminum alloys. To reduce weight and maintain strength, manufacturers are embarking on various tricks. making them hollow, having intricate cross-sections.

Sometimes (more often on inexpensive bicycles) the block of front sprockets is made in the form of a non-separable structure, combined with the right connecting rod, and then when replacing the sprockets, both connecting rods have to be replaced. On mid to high end bikes, the front sprockets can usually be detached from the right crank arm, meaning they can be changed independently as the teeth wear out.

The need to replace the connecting rods also arises when they are broken or damaged. You have to remove the connecting rods (one or both) in order to get to the carriage (to adjust or replace it).

Usually new connecting rods are purchased together with chainrings.

When buying new connecting rods, it must be borne in mind that there are several types of carriages that differ in the type of axle. Choose connecting rods that are compatible with your existing bottom bracket. In addition, the connecting rods are available in different lengths (from 165 to 180 mm). Crank rods that are too long on a small frame can be inconvenient when riding on uneven terrain, and too short will require extra pedaling effort.

READ  How to properly adjust your bike's gear shifting

Removing the connecting rods from the bike

In addition to the puller, an 8 mm hexagon is required. If the connecting rods (especially aluminum) have not been disassembled for a long time, you will need to fill the connection with machine oil, WD40 or some kind of “liquid wrench” so as not to rip the threads on the connecting rods.
Before screwing in the connecting rod puller, make sure that the diameter of the “finger” of the puller, which will press on the square axis with the connecting rod fixed, is less than the size of the square hole. It so happens that a movable head is put on the finger of the connecting rod puller, the diameter of which is larger than the square hole of the axle. The consequences are dire if you do not stop in time. The stripper rests against the connecting rod itself and begins to squeeze out not the connecting rod, pushing the axle forward, but itself, “brutally” cutting off the thread. The advice would be redundant if such cases did not occur.
Having unscrewed the bolt, screw the puller into the connecting rod until it stops. The thread in the socket must be cleaned before this, and the screw of the puller must not protrude into the connecting rod (otherwise the puller will not be screwed in as deeply as it should). Then we tighten the puller bolt, squeezing the connecting rod off the shaft. It can take a lot of effort. be careful! If you overdo it, the thread inside the connecting rod will be torn off and you will have to change it (not to mention the problems of further removal), so you should not save time on “soaking” in oil.

How to Replace a Chainring on your Bicycle

Bicycle crank puller

Connecting rod puller (system puller). a tool that allows you to remove the system from the non-integrated carriage shaft. Usually combines two functions: a hexagon for disassembling pedals-treadmills and the actual puller.

The connecting rods are held on the carriage shaft by a bolt for an internal hexagon 8 mm But it is not enough to unscrew the bolt, since the connecting rod sits with an interference fit on the carriage shaft and sometimes “sticks”, so a special puller is required. It is a screw with a two-piece head (socket wrench and open-end wrench), onto which a special shaped nut with an internal and external thread is screwed. Often an adapter is included with the puller for use with slotted standard carriages.

Bicycle cranks

We discussed what shifters and stems are. Today we will talk about connecting rods for bicycles and
how to change them, what are the connecting rod removers and how to remove connecting rods from a bicycle.

Bicycle cranks: 10 comments

Why does this have to be the ONLY reliable socrue? Oh well, gj!

Tools for the job

How to replace front sprockets. video

How to replace asterisks?

If your goal is not just to replace the outer sprocket. which can be easily done by removing the fasteners and threading it through the connecting rod. you will have to start by removing the drive sprockets. 2. Some high-quality connecting rod systems allow you to remove the sprocket bolts with ordinary hexagons or special Torx wrenches, but if your sprockets have ordinary bolts, you need either a special puller wrench that is placed in the slotted groove of the sprocket nut or another hexagon (often 1 mm larger than the front), which keeps the nut from turning. A special wrench. a puller keeps the sprocket nut stationary while unscrewing or tightening the bolt.

Lock the nut and unscrew the bolts counterclockwise. Remove them carefully, they will come in handy for installing new sprockets. You can now remove the old chainrings or clean them thoroughly if you only replace the outer chainring to change the gear ratio.

How to replace front sprockets on a bike?

Change chainrings on your bike with our step-by-step video tutorial. Replacing the sprockets on a road or mountain bike is a fairly straightforward task, but one that needs to be done urgently when the cogs wear out. You can swap the chainrings to change the gear ratio, lowering which will make it easier to climb slopes, and increasing it will speed up in flat races.

READ  How to adjust the front bottom bracket on a bicycle

Before starting work, find out the exact landing diameter (PDD) of your leading star system before purchasing new ones. Typically PDZ 110 or 130 mm. or significantly reduced or traditional size. If the bike is equipped with a 50x34T system, then the PDR is almost certainly 110 mm. If it is 53x39T, then the PDZ will be 130 mm.

Of course, you can always measure the circumference of your system to be sure. There are exceptions, such as the “four feet” used in Shimano’s newest 11-speed hitch, for which sprockets of various sizes are available without worrying about the difference in PDL.

Replacing stars

The outer star, usually the largest, has a small pin protruding from one side. The sprocket should be positioned so that the pin is behind the crank arm to prevent the chain from being completely seized if it comes off and falls between the outer sprocket and the crank arm. The inner sprocket usually has a small mark in the middle of the outer edge, which should also be placed behind the crank arm.

The chamfered edges of the cogs. which aid in gear shifting. either the brand name or any other markings must be visible from the outside when the sprocket is installed.

Place the sprocket with the markings facing outward, thus positioning the teeth correctly for smooth gear shifting. When the sprockets are positioned correctly, insert the nuts into the holes. Fix them with a special wrench or hexagons, then screw the bolt into the nut clockwise until you feel a slight resistance, while fastening the sprockets.

Repeat these steps for all bolts, and then alternately tighten each bolt a quarter turn at a time until it stops. A torque wrench can be used to do this by tightening the bolts to the torque indicated on the bolts.

Install the sprocket connecting rod onto the axle, remembering to thread them through the chain. Pedal and change gears to make sure everything is working properly. If you have resized the outer sprocket, you may need to readjust the front derailleur for smoother speed changes.

How to properly shift gears on a bike

There are many gears in a modern bicycle. Every day, manufacturers are introducing an increasing number of speeds into their models. Whereas about a decade ago, Shimano Alivio’s initial line of components was designed for 6 stars in a cassette (i.e. 3×6 = 18 speeds), today bicycles are fitted with 9-star cassettes in this class (3×9 = 27). Even recently popular (only a year or two ago) 8-star cassettes are now rarely seen, except on cheap bicycles. All this is done not only for the sake of marketing purposes, but also to improve the performance of the transmission: firstly, the speed range expands slightly, and secondly (and this is more significant), the jolts from changing the gear ratio become smoother. The load on the chain and sprocket is reduced, which increases the life of the components.

How to deal with all this economy correctly? How to properly shift gears on a bike? Let’s figure it out. These tips come in handy for all cyclists with more than one gear on their bikes. Although no, just everyone, so that you can teach the mind-mind of your friends-acquaintances.

Learning to switch correctly

Each program, like a good joke, should be appropriate. On the ascent we go down, on the descent we go up. The pedal effort will tell you the right gear ratio for your driving conditions. If it becomes difficult to turn, you should switch lower, too easy. higher. But in any case, the load on the legs must be maintained, you need to rotate the pedals vnatyag. this is the only way pedaling will be effective.

Regarding the speed (cadence). Each person is comfortable with their own cadence, at which the pedals will rotate with maximum efficiency. If the speed of rotation is lower than the rhythm you are comfortable with, then the strength will be wasted. If the cadence is incorrect, there is also a risk of injury. This is due to increased stress on the joints and muscles. So pay attention to this point when driving.

READ  How To Fix A Speed Switch On A Bicycle

You don’t need to pedal too quickly, otherwise you will quickly get tired. Finding the ideal frequency for yourself is not difficult; rely on sensations. I will only add that in addition to road conditions, the choice of gear and cadence is influenced by the strength and direction of the wind, as well as the physical form of the cyclist at the moment.

Under any conditions, the goal is the same. to pedal at a constant speed and constant effort on them, regardless of the selected gear. The same rhythm significantly postpones the onset of fatigue and increases endurance. Consequently, a significantly greater distance can be overcome.

Bike Maintenance: How to Replace a Chainring

Transmission device

In a nutshell about the structure of the gear shift system. Modern bicycles have two derailleurs. front and rear. They are controlled through the shifters: the left one is for the front derailleur, the right one is for the rear. The number of positions on them must correspond to the number of stars in the crankset and in the cassette.

Bicycle transmission device. The principle of operation of the front derailleur is quite simple. it moves the chain from one drive sprocket to another. The rear derailleur is more complex, since it is assigned the function of tensioning the chain, the length of which changes from star to star. It has a double roller foot and a powerful spring. Thanks to this design, the chain does not randomly jump off and does not sag, and if necessary, with the effort of one finger, it quickly and clearly moves to the adjacent sprocket.

How to properly shift gears on a bike. basic recommendations

The pedals can only be turned forward when shifting. Some “unique” (mostly children, regardless of age) like to do the opposite, scoffing at the bike. Bad example to follow, agree. And the power gap does not contribute to effective acceleration in any way.

At the moment of switching, it is necessary to slightly reduce the force applied to the pedals. The shift to another gear will be smooth, without bumps, which positively affects the durability of the entire transmission.

As you gain experience, you will intuitively find chainring and chainring combinations. If you have not yet fully mastered the switching system, follow the position of the chain in one position or another. There are more than two dozen gears (the overwhelming number of bicycles today have 24, 27 and 30 speeds), but only two thirds of them can actually be used. The problem is severe chain misalignment that occurs when the outer chainring and inner (closest to frame) rear chainrings are used, and vice versa. The chain and sprockets in such sprocket combinations deteriorate quickly, and the rear derailleur is under increased stress. The coefficient of friction is generally higher, which requires extra effort from the cyclist motor. After all, it’s noisy.

Incorrect gear combination. Therefore, we remember: large chainrings and small rear ones are gear ratios for fast driving, a small front and large rear ones are for off-road and overcoming obstacles. It is impossible to combine “fast” with “slow”.

Take your time: shift gears one at a time, not several at once. Wait for the chain to move to an adjacent star, and only then continue switching.

Shifting uphill On uphill gradients, it is not recommended to change gears due to the increased loads on the entire transmission. Therefore, choose a gear suitable for its slope in advance. Immediately exclude the large front one from the possible options, since it will be very difficult to climb up with it.

Keep your bike clean, lubricate and adjust mechanisms in time.

Most importantly, be smart about cycling.