When to change a tire on a chainsaw
Chainsaw tire: how to measure, select, install and repair
The control of chain movement with the fixation of its tension and regular lubrication, is provided by one simple and absolutely irreplaceable element. The saw bar belongs to the category of expendable parts, because it takes peak loads, deforming and seriously wearing it as it works. This article, briefly and clearly shows what criteria for selecting a new part, how to install it on a tool and make easy repair.
The general idea of any element is formed by knowing its parts and understanding their interaction. In order to run the tire as long and efficiently as possible, it’s helpful to have a clear picture of how it works. The functional role of a part in a chainsaw system is clear to anyone who has ever observed the tool in action. The bar is first of all a guide rail for the chain as well as a means of tensioning and lubricating it.
A cursory examination of the element gives the impression that it is carved from a single sheet of metal. In fact, the tire consists of 3 plates (2 side plates and one central plate), securely fastened by rivets. The central element is considerably shorter and thinner than the side elements, due to the grooves in the chain guide, into which the chain shanks are immersed. The free space at the front (nose) of the bar is occupied by the chain drive sprocket that ensures the free movement of the chain when tensioning.
To facilitate movement and protect it from wear, the sprocket is mounted on a bearing, the central part of which is riveted to the side plates. For the maintenance of the mechanism, expressed in cleaning and lubrication of the rollers, special holes are provided on both sides of the bar.
At the tail end of the chain guide, there are a number of service holes. The largest, elongated opening, provides an even installation of the blade, along the two studs secured to the engine crankcase. one of the two symmetrically arranged holes holds a pin of the chain tensioner and the smallest hole has an oil pump connector that supplies lubricant to the chain shank during operation.
How to choose a guide bar for a chainsaw
The variety of chain guides is quite extensive, but it cannot be called overly impressive. Modern saw bars are categorized in width of groove, length of blade, sprocket pitch and shank. Based on these values, a selection of replacement peripherals is made. Let’s look at each parameter in order, starting with the most important.
The length of the saw blade determines the maximum depth of penetration into the material and the permissible chain size that can be fitted on it. According to the standard, the values are expressed in inches and indicated on the part itself (near the shank), along with the recommended number of links. Standards differ depending on the sprocket pitch. The data for the most common variations are shown in the following table.
In order to avoid a reduction in the service life of a domestic saw, it is highly recommended not to mount a long guide bar (more than 45 cm) on it. The larger the contact area with the wood, the harder it is for the engine to work, thus, the faster the wear on the cylinder head. Many Chinese machines are equipped with bars on 45 cm, in order to draw attention to the product. Of course the tool can handle the load, but if you put a 38 cm on it, it’s much livelier.
The bar shank can be universal or branded, which will not fit most saw models. Each manufacturer recommends its own tooling, and sometimes blatantly imposes products, making it impossible to use other options due to the unique arrangement of technological holes. If you mount a STIHL bar on any other brand of saw, for example, you will have a lot of trouble with the chain and the tensioning and lubrication holes will not match.
Recommendation. If you buy a bar for a simple chain saw (not STIHL, Makita, Husqvarna), look for a universal bar that has a closed shank. To be sure, use the old rail or the model of the tool as a guide.
The guide bar sprocket allows the free movement of the blade in the bend. As standard, the teeth can be ground to a chain pitch of 0.325 and 3/8 inch (rarely 0.404 и 1/4). Even though it is possible to combine elements of different sizes, working with such a combination is strictly forbidden, because of increased wear and probability of breakage.
To determine the required sprocket pitch, refer to the markings on the side plate of the tire. If the data is erased, you can measure the chain used by knowing the distance between the centers of the first and third rivets, anywhere. Metric Conversion of inches into the metric system gives the following values: 0.325″ = 8.25 mm, 3/8″ = 9.3 mm, 0.404″ = 10.2 mm and 1/4″ = 6.35 mm.
The width of the slot determines the allowable dimensions of the shank to be plunged into it. This indicator indirectly indicates the class of the device. Simple, domestic guides, are equipped with chains with the thinnest shank, 1.1. 1.3mm. Amateur tooling has a wider groove, by 1.4. 1.5 mm, and bars for professional saws can accommodate shanks from 1.6 to 2.0 mm.
To increase stability and efficiency, even the smallest play should be eliminated. the position of the chain in the guide must be tight, but without hindrance to movement. To find out the required slot width, you can measure the chain shank with a caliper, or experimentally by putting it on a new tool.
By determining all of the above values you will form a clear picture of the required part and no selection error will occur. As a final touch, it is useful to know how the chainsaw bar length is measured and how important the number of chain links is. A brief breakdown of the topic, below.
How to measure the length of a chainsaw bar
Choosing the right guide depends on knowing the specific characteristics of the part design. Among the most important and ambiguous parameters, is the length of the chainsaw bar, which is measured in two ways.
The fastest but not the most accurate option is to use a straightedge or tape measure. The important thing is that you don’t measure the entire bar from start to finish, but only the working part of it, which starts after the end of the main fastener notch (approximately). we divide this value by 2.54 (centimeters into inches) and round the number up to one of the common standards: 10″, 12″, 14″, 16″, 18″, 20″. For a complete list of current sizes, see the table above.
The second method involves calculating with the available chain. First, you should find out the pitch by measuring the distance between the centers of any 3 rivets and dividing the value by 2 (8.25 mm is 0.325 inch, and 9.3 mm. 3/8″). Next, count the number of links by shank. For 3/8″ the value can range from 40 to 68, and for 0.325 pitch is 64 to 76 chain shanks. Knowing the exact number of links and pitch, we go to the above table of dimensions and determine the length of the bar by comparing the 2 values.
Signs of chainsaw chain wear
Natural wear and tear on the chain’s cutting links is not the only reason to change the chain.
- It is better to look in the owner’s manual which will advise you how to choose the right headset. They are found during visual inspection.
- Deformation of rivets and connecting links, cracks are caused by excessive tension in the chain and can lead to loose chain and need for replacement.
These signs tell you that your chain is damaged and it is time to replace it. In this case it is strictly forbidden to work with faulty chain. It can break suddenly and injure you severely.
What you should know when choosing a chain
If you have determined that it is time to replace your saw headset, you need to know how to choose the right headset. The easiest way to do this is to consult your operator’s manual, which has recommendations on the subject. fdfmoto has a great selection of chainsaws for different brands.
Another way is to use the markings on the old chain to find the same.
To avoid making a mistake when buying, you need to know the following data:
All chains are divided by size, based on pitch, which is measured in inches. There are sizes 0,325. for household saws, 3/8 or 0,375. for semi-professional and professional, and 0,404. for professional tools.
drive link thickness. This size is determined by the width of the chain groove in the bar of the tool. their difference also depends on a class of the chainsaw the more professional the tool the higher this figure.
This knowledge is enough to orient oneself in the range offered by the market.
Of course not everyone has the opportunity to buy new, although it’s still a question of what’s better, whether it’s new or proven old. And how not to get a “cat”. With the chain everything is clear, there by the longitudinal length of the tooth, the longer, the newer. In a tire, look and measure the depth of the groove where the chain goes. If the chain walks on the “bottom” it is a scrap. If it’s 3-4 mm longer than the guide tooth, it’ll still work.And the width of the groove.
The chain saw guide bar is the guide and securing element of the saw headset. The blade itself, the drive sprocket and the fasteners are consumables.
Working with a faulty guide bar is very dangerous because at high RPM it can come off the body and injure the operator, or because of poor fixation on such a bar the chain can jump off and cause injury.
Most often the wear and tear of this chainsaw element occurs naturally, as a result of prolonged use. Because it carries the main load when making cuts. But there are situations where the guide bar can break because of improper use. Excessive loads that do not correspond to the tool’s specifications.
Or by not caring for your chain saw properly. In addition, it also happens that a low-powered machine is fitted with a professional or semi-professional guide bar, or vice versa, a pro or universal class tool is fitted with a guide bar designed for household saws.
First of all, the bars differ from each other in terms of length. For example, 11 and 13 inch bars are suitable for household saws, 14 to 16 inch for universal and professional saws. Also elements differ in design features. There are flat and narrow blades, there are two-piece blades with polyamide joints, and finally, blades with removable heads.
The latter two types are used on semi-professional and professional saws. The FDFmoto online store has a large selection of tires, fasteners and other accessories for power tools. https://fdfmoto.com/eng/catalog/shinyi-dlya-benzopil
How to determine the wear of a chainsaw guide bar
The chainsaw guide bar is the guiding and fixing element of the saw headset. The blade itself, the drive sprocket and the fasteners are consumables.
Work with a failed bar is very dangerous, because at high speeds it can tear from the body and damage the operator, or because of poor fixation on such a blade can jump off the chain and cause injury.
Most often, the wear of this element of the chainsaw occurs naturally, as a result of prolonged use. Because it carries the main load when making cuts. But there are situations when a guide bar breaks as a result of improper use of the tool. Excessive loads that do not match the tool’s specifications.
Or a lack of care for the chain saw. It can also happen that a professional or semi-professional guide bar is mounted on a low power tool or vice versa, or that guide bars are mounted on professional or universal tools for household saws.
Above all, the guide bars differ in length. There are 11 and 13 inch bars for home saws, 14-16 inch for universal and professional saws. Also the elements differ in design features. There are flat and narrow blades, there are double blades with polyamide jointed to each other and finally blades with a detachable head.
The last two types are used on semi-professional and professional saws. The online store FDFmoto has a large selection of tires, fasteners and other accessories for power tools. https://fdfmoto.com/en/catalog/shinyi-dlya-benzopil
How to spot a broken guide bar
If there is a problem with this part of the saw, it is quite easy to spot it:
- The bar doesn’t fulfill its main functions, it doesn’t have the necessary tensioning and lubrication of the chain.
- The bar is either too tight or too loose. Unusual play appears in the area where the bar is fastened.
All of these are clear signs that it is time to change the guide bar.
To extend the life of a chainsaw guide bar, it is important to clean it after each use. Carefully clean dirt and sawdust in the grooves, where the chain is located and in other fastening points.
Almost all chainsaw manufacturers recommend changing the saw blade after replacing three chainsaws. Because even if the bar looks perfectly normal and functional, in the process of constant chain rotation the groove expands and the chain in the bar starts to play. Which can be very dangerous for both the tool and the operator.
Tire selection criteria by quality characteristics
Uniform fitment sizes are available in a small range of tires. As a rule, each manufacturer uses its own standards, which eliminates the possibility of operating a chainsaw with other brands of saw equipment.
- The selling price of guide bars is determined by size, material quality and brand awareness. The most expensive products are the highest quality and long service life of the leading manufacturers.
- High price of brand name bars is fully compensated by high wear resistance and long service life.
- In the medium-price range. the range of budget tires, which are equipped with gasoline and electric saws of household class. With competent use and skilled maintenance, the Standard category tires produce a longer service life than the manufacturer prescribes.
Less popular are cheap, short-lived Chinese-made tires, which are installed on chainsaws of minimum price range. Many of these products are sold under well-known brand names.
How to exclude possible risks of purchasing counterfeit tires?
In the information field there are signs by which it is not difficult to distinguish the original brand-name chainsaw from the most authentic fakes. As for tires, their advantages and disadvantages are revealed directly in operation.
In the domestic market of home appliances about 15% of the total sales volume of chainsaw parts are third-rate counterfeit of unknown origin, which develops a standard resource in half at best.
It is not economical or safe to operate a chainsaw with a counterfeit tire and chain. A considerable part of traumatizing situations is created when using counterfeit tire and chain.
You can buy a quality and durable brand-name chain saw of the required model without considerable risks at a brand outlet or representative office of a licensed dealer company. In the absence of such a possibility you should use the services of a solid, trustworthy online store.
What you should know when choosing a chain
If you have determined that it is time to change the saw chain, you need to know how to choose it correctly. The easiest way to do it is to refer to your user manual which contains recommendations on the subject. At fdfmoto there is a large selection of chainsaw chains for various brands.
Another way is to use the markings on the old chain to find the same.
To avoid making a mistake when buying, you need to know the following information:
All chains are divided by size based on pitch, which is measured in inches. Sizes are 0,325 for consumer saws, 3/8 or 0,375 for semi-professional and professional tools, and 0,404 for professional tools.
The thickness of the drive link. This size is determined by the width of the chain groove in the bar of the tool. the difference also depends on the class of the chainsaw, and the more professional the tool, the higher the number.
This knowledge is enough to navigate in the range offered by the market.
Proper operation of any tool must ensure the efficiency of its operation, the safety of the worker and the safety of the tool itself. The chain saw’s special features include their high potential for injury. That is why chainsaw safety requirements are an essential element in the chain saw’s operating rules.
A chainsaw is considered to be ready for service if it has been serviced and repaired:
- all assemblies and mechanisms are in good working order;
- a sharp, properly tensioned chain is installed;
- the fuel and oil tanks have been filled;
- the carburettor is adjusted.
Proper chainsaw maintenance involves the timely performance of all operations to ensure that the tool is kept in good working order. The most important of these are: cleaning the air filters, adjusting the carburettor, cleaning the spark plug and adjusting the gap between the electrodes, sharpening the chain and replacing wear parts.
A new chain saw requires a run-in period of 40-50 minutes at low rpm, after which the chain saw is turned off and the chain tension is additionally checked. Then you need to make some cuts, using only light force, and only then can you work normally.
Installing the chain and tensioning it
With a chain sprocket, remove the sprocket cover (1) by unscrewing the nuts (2).
It is important to remember that before every assembly or disassembly of the chain sprocket cover, the chain brake must be loosened by pulling the brake stop (1) (see Fig. The chain should be easy to pull and the clutch drum should rotate (see photo below) in the direction of the crank (2).
The pin (1) that enters the bore of the bar must be shifted into the groove to the left-most position. This is done by means of the tensioning screw (2).
The chain should be wound up behind the clutch (1) and put on the drive sprocket and put on the bar. Pay attention to the position of the cutting edge of the tooth. on the upper chain strand the cutting edge must point forward. The chain should pull easily, the clutch drum should rotate as the chain advances.
Then turn the tensioning screw (1) to move the bar forward until the lower chain strand is inserted into the bar groove with its shanks resting against the lower bar. The final adjustment of chain tension and tightening the bar is made after installing the cover in place and preliminary (not all the way) tightening the fixing screws.
For more convenience, the chain tensioning screw can be located on the side of the bar.
A properly tensioned chain should not sag at the bottom and have too much tension. The first is checked visually, the second by pulling the chain across the bar by hand. The last operation must be done with gloves on to avoid cutting. If the bottom strand is close to the guide bar bottom edge and the chain can be pulled through freely by hand, the tension of the chain is within the recommended tolerance.
When checking the tension of the chain, the chain brake must be released if it has accidentally caught the chain. Check chain tension frequently. new chains tend to elongate during use.
While cutting, the chain becomes hot and lengthens due to friction. The chain tension is loose and the chain slackens on the underside of the bar. If you are working in very cold ambient temperatures, the chain that has been warmed up to operating temperature will sag so much that it must be retightened. If the chainsaw operation is interrupted, the chain must be loosened immediately or the chain will be stretched too much when it cools to ambient temperature. This can cause chain breakage, as well as crankshaft and bearing damage.
Maintaining a chain requires periodic inspection, sharpening in good time, and replacing it when excessive wear or other flaws that interfere with safe and efficient use are noticed. To learn how to sharpen the chain, see How to Sharpen a Chainsaw.
Every moving part needs some time for lapping when first entering service. Despite careful machining, every surface has microscopic roughness that is smoothed out during lapping. New chains have a break-in time of approximately three minutes. The engine should run without load (no sawing) with half the fuel-air mixture. In the course of this time the chain surfaces flatten out and material settles, the chain slackens, and must be retightened. The frictional forces are very high during break-in, so it is important to make sure the chain is sufficiently lubricated.
Filling up your chain saw
For example, here is an oil for the engine, and here. for the chain (only better to buy through an online store, t.к. The price may be higher in a regular chain store).
Dilution of oil in gasoline is made in a certain sequence. First pour the oil into a container (jerry can), then add a suitable petrol for the chain saw. about half the quantity needed. After stirring thoroughly, add the second half. Before pouring the mixture into the fuel tank. shake it up well once more. The fuel should be poured with care, without spilling anything. Do not pour fuel to the very top of the tank; leave small clearances at the top. The fuel tank capacity of chainsaws is usually about 0.5 l, and with a 2 kW chain saw (2.7 л.с.) and with a fuel consumption of about 1.Approximately 2 liters per hour. enough for about 30 to 40 minutes. and maximum-load operation. Less powerful chainsaws usually have a smaller fuel tank.
Why the chain comes off
Many chain saw users, even the most experienced ones, have faced the problem of the chain jumping off the guide bar when working. The most common cause is insufficient tensioning or wear of the chain.
In 80 % of the cases the elongated chain links slip off the sprocket teeth and the chain rushes off the guide bar due to the centrifugal force. Sometimes, though, the problem is caused by the wrong position of the sprocket in relation to the axis of rotation or a chain saw bar that is not securely fastened.
There are now many chainsaw chain models on the market. The good thing to know is which size fits your chainsaw so you can buy the right one. The second step is to install it correctly on the chainsaw. This is a somewhat time-consuming process, but if you know how to put and adjust the chain on the saw bar yourself, the good owner should not have any problems. We have tried to describe in detail the process of installing the saw blade on the chainsaw.
We hope you will be able to do it right the first time after reading this article. But in order to minimize the appearance of problems with the chainsaw and the chain in the future, do not forget the 3 basic rules:
- If the chain is worn and sagging. replace it with a new one;
- If you feel vibration and the cut is bad, check the chain tension on your chain saw;
- Never use defective or repaired by dubious specialists saw blades, your health and the health of those around you are much more important than small savings on the purchase of a new and reliable chain.
The first thing you need to learn from a new chain saw wizard after learning how to work safely with a power tool. is its adjustment. The next thing to do after reading the instructions. is to check the operation, and if the saw does not work properly, the likely cause is improper chain tensioning. So the question immediately arises. How to pull the chain on a chainsaw?
Usually manufacturers indicate in the chainsaw instructions how to do this, but if for some reason it is lost or the device received without it, for example, by inheritance, the text below will help find the right answer.
How to tension: setting the cutting element of a chainsaw
The main causes of a sagging chain we’ve sorted out. About how to set the chain on the chainsaw, it was told by the paragraph above. Now we have to tighten the chain correctly and check if it’s not too tight.
There are two ways to tighten the chain: fast and front. The best way to pull the chain is to pull it from the front.
If it is necessary to carry out front tensioning, it is necessary to unscrew nuts which hold a tire and to lift it behind an edge. Use the special bolt on the right to tighten the chain until it has an acceptable tension, and then raise the bar even higher and clamp it.
A chainsaw is a very useful thing at home. After all, it quickly and relatively easy to solve a lot of home construction, gardening and landscaping tasks. A chainsaw is a rather capricious tool, but if handled properly it is an irreplaceable helper. It has one weak point: the guide bar. That is where most of the operating loads are applied. That means that knowing why guide bars fail more often than other chain saw parts and how to properly replace them when necessary will help you save money and time during seasonal or project work with your tool.
Chainsaw tire mounting
The bar and its mounting elements are consumables. Wear of this assembly occurs both under operating loads and as a result of improper operating conditions. You can tell right away if there is a problem with this part. The bar cannot provide proper tensioning, lubrication and running of the chain. The saw’s axis of motion is locked in relation to the tool’s body.
It is not safe to operate a saw if the guide bar is defective. That’s why at the first sign of a faulty assembly you need to turn the motor off and find out what’s wrong. Knowing the bar and how it is mounted on your chainsaw will help you successfully troubleshoot the problem.
The bar determines the axis and length of the cut, guiding the chain. But the basis of the mechanism is still the mount. It is installed in the groove between the inner plate on the motor housing and the outer plate located on the chain guard. The bar and the cover are bolted together. This part of the attachment is called the “engine assembly” and its shape and design depend on the chainsaw model. The bar holder and drive sprocket are covered by a separate cover.
The drive links in the saw chain are fitted in the guide groove on the bar edge and engage with the sprocket which is connected to the universal joint shaft. If the fixing bolts are loose, the bar could move. Chain tension can be adjusted manually or. like on professional chain saws. automatically. Finally, there is a stop at the front of the bar mount. This serves to keep the saw axle firmly in place as the moving chain comes into contact with the wood.
The bar should have proper tensioning of the chain. To check if the chain slips, release the chain brake and pull the chain by hand in the direction of movement. If the chain won’t move, the fastener is too tight. This should be loosened slightly, and then the chain should be checked again for freedom of movement.
Why does the chain jump?
Many chain saw users, even the most experienced ones, have had to deal with a situation in their lives where the chain has jumped off the guide bar during operation. The most common culprit is insufficient tension or wear of the chain.
In 80% of the cases, the stretched chain links slip off the teeth of the drive sprocket, and the chain is centrifuged out of the guide rail. Sometimes the problem is caused by wrong sprocket position in relation to the pivot or a saw bar that is not securely fastened to the chain saw.
There are a lot of chainsaw chain models on sale right now. To get started you need to know the right size for your chainsaw and make sure you buy it correctly. The second step is to install it correctly on your chain saw. This is a somewhat time consuming process, but if you know how to put on and adjust the chain to the saw bar yourself, the good owner shouldn’t have any problems. We have tried to describe how to mount the sawblade on the chain saw in detail.
We hope that after reading this article you will succeed the first time. But to minimize the occurrence of problems with the chainsaw and chain in the future, do not forget the 3 basic rules: