Choosing a bicycle helmet. How to properly adjust and wear a bicycle helmet?

What I like about the Planetovskaya checkpoint is that it can be disassembled and repaired without disassembling the engine or even removing it from the frame: directly in place, without even draining the oil: we lay the motorcycle on its side and repair it - this is actually in terms of repair and the service is very convenient.

The second pleasant point is that the gear ratios of the first second and third gears in the “Planetovskaya” gearbox can be changed at your discretion by simply selecting gears and shafts from other models of motorcycles of the “Planetovskaya” series. Thereby making the desired gear faster or more high-torque.

Deciding on the type of helmet

Just as bicycles are designed for different riding purposes, helmets are divided into types. You need to clearly understand which category of cyclists you consider yourself to be and make a choice based on this information.

Racing models are priced from about $60 to $230. Such a high cost is explained by its low weight, well-organized ventilation, and design with aerodynamic elements. This equipment is distinguished by its oblong shape and a large number of holes. Such an expensive purchase would be appropriate for athletes, cyclists, professional cyclists and extreme sports enthusiasts.
Sports models are much cheaper than racing ones. Their prices start at around $35 and rarely exceed the $55 mark. Such equipment is often chosen for city riding, highway riding and mountain biking. Sports bicycle helmets can also be seen on skateboarders and rollerbladers.
Downhill models are similar in appearance to motorcycle helmets, but they weigh much less. Such items of equipment include chin protection. Downhill helmets are made from carbon and fiberglass, which makes them very durable.
BMX helmets are very similar in design and weight to the previous type of uniform, but have a difference in the form of a large square-shaped visor.
Track models have an aerodynamic elongated shape, which is suitable for high-speed movement. The disadvantage is the lack of ventilation holes, but this is necessary for a high level of aerodynamics.
Skating models have a round shape, durable construction and small holes to maintain ventilation.
For a mountain model you will have to pay from 50 to 130 dollars. This type of equipment is highly durable and has good rear visibility. Such helmets can easily be confused with racing models, but the latter lack a visor, which is a distinctive characteristic. Mountain helmets must fit firmly on your head so that they do not fall off or move when going through bumpy areas. Cyclocross riders often choose these items of equipment.

To choose the right helmet, you need to clearly know which riding style will be most advantageous for you. If the helmet matches the style and riding conditions, then the level of safety and comfort will be maximum.

Bicycle helmet

Assembly

In a carefully washed and prepared for assembly crankcase we place the input shaft, the first gear gear and the follower shaft with pre-selected shims.

We put a fork on the gear-carriage for engaging the second-fourth gear (it is smaller than the gear-carriage for engaging the third-first gear, you can’t go wrong) as shown in the picture. We put the gear on the input shaft and insert the fork pin into the upper groove of the follower shaft.

We put a fork on the gear-carriage for engaging the first-third gear, as shown in the picture, place it on the first gear gear and insert the fork pin into the lower groove of the copy shaft.

We install the fork guides in their places (with grooves towards the clutch basket). By the way, if necessary, the “Planetovskaya” gearbox can be assembled and disassembled without disassembling the clutch basket and without removing the guides. But to do this, during installation you will have to pull the tracing shaft towards you a little, insert the pins of the forks into the grooves and after that, remove the locking bar and push the tracing shaft all the way.

Install the intermediate shaft.

On older engines, the end gear is installed separately. On later ones, it is made integral with the intermediate shaft.

We fill the return spring of the gear shift shaft as shown in the picture.

We check the functionality of the gearshift shaft pawls: compress and unclench them several times. We pay special attention to their working edges: they should be sharp and not licked. And don’t forget to check the spring that compresses the pawls: it must be of the correct shape and ensure the elasticity of the pawls’ movement.

We squeeze the pawls and install the gear shift shaft in its place.

We rotate the tracking shaft with the mark on the body towards the gear shift shaft and so as not to miss the mark during installation, we cover the gap between the teeth opposite the mark of the tracking shaft with lithol or paint it. It will be more noticeable this way.

We look for a mark on the sector and when putting the sector on the gear shift shaft, we combine the mark on the sector with the mark on the tracking shaft body: the tooth opposite the sector marks should strictly fit between the teeth opposite the mark of the tracking shaft.

To ensure that our marks do not get lost during installation, we tie together the sector and the copy shaft with ordinary sewing thread.

We put standard thrust washers on the input and follower shafts and insert the guide bushings of the gearbox cover into place.

We degrease the surfaces, apply sealant, lay the gasket, install the cover and tighten the mounting bolts with the maximum possible force. We adjust special washers under the bolts marked with yellow arrows.

After tightening the gearbox cover, we check the axial play of the primary and secondary shafts. Normal: 0.2-0.4mm.

If the play is greater than normal, remove the plate, seat the bearing and adjust the required number of shims under it.

Some useful tips.

If your helmet comes with its own instruction manual, be sure to read it before riding.
Do not use chemical solvents to clean the helmet. Manufacturers recommend using a soft cloth or sponge with mild soap and water.
Do not store your helmet in the attic, garage, trunk of a car, or in the heat. In extreme heat, bulges may form on the helmet. Do not wear such a helmet.
Do not lend your helmet to anyone or use someone else's helmet. You must know how the helmet has been handled throughout its lifespan in order to properly assess its condition over time.

Summary: what to look for

First, make sure you buy a helmet that fits properly; a poor fit can negate any protection you may have.

You should like the helmet, even if it seems comfortable. Otherwise, you probably won't want to wear it.

And, of course, the helmet should match your riding style. Don't go downhill with a regular road helmet and don't ride on the highway with a full face that restricts your view.

Read more: How to choose the right cycling shoes

How to choose a helmet size

If you decide to buy a bike helmet online, which is not a very good idea (we’ll tell you why later), but it happens that there are simply no other options, then you should know some parameters, namely the circumference of your head. It is measured at a line 2 cm above the eyebrows. Knowing this parameter, you can choose a bicycle helmet using special size tables. I would like to note that you can only choose “blindly” cross-country, road and enduro helmets (since they have size adjustment), but other types should be measured without fail. Below we provide a size chart for adults (men, women), teenagers and children.

Triathlon helmets

In a long triathlon, where each participant rides solo, there is a reason why aerodynamic helmets are used for time trial racing. Triathletes' heads most often feature helmets with a truncated tail.

No rider will be able to ride a 180 km or even 90 km cycling stage without changing his head position, so a tailed helmet will only spoil the aerodynamics if you lower your head or twist it.

All other things being equal, a rider wearing a properly fitted aero helmet will be faster than the same rider wearing a standard bicycle helmet. Imagine how many seconds and even minutes accumulate when it comes to 180 kilometers of cycling.

However, there is a factor that should be taken into account. An aero helmet will always ride hotter, and overheating can easily cost you more time than the helmet saves. An excellent intermediate solution would be a road helmet with an aerodynamic design.

Shelf life of a bicycle helmet

As strange as it may sound, bicycle helmets have a shelf life that does not depend on whether you fell while wearing it or whether it was just sitting in the closet. This is especially true for road and cross-country models. The thing is that over time the foam base dries out and deteriorates. On average, even a completely new helmet is best replaced after 5 years from the date of its production.

Based on the above, it is categorically not recommended to buy a used bicycle helmet, since you do not know how old the product is and whether it has been subjected to strong impacts (as was written earlier, the external appearance of the helmet can be almost perfect, but inside the base it is damaged by microcracks). Therefore, if you decide to buy a used bicycle helmet, it is better to do it from familiar cyclists whom you can trust.

Important features of a good bike helmet

Once upon a time, the quality of a bicycle helmet was determined by its impact resistance, but now a number of characteristics have been added to this:

Weight is especially important for sports racing helmets.
Aerodynamics are also of interest only to those who want to squeeze the maximum out of the speed potential.
Ventilation – Usually helmets for mountain biking and everyday city riding have a sufficient number and width of ventilation slots, but in road and especially aerodynamic helmets, engineers have to contrive to maintain optimal levels of aerodynamics and ventilation. By the way, the more ventilation holes, the lighter the helmet will be.
Visibility is the reflective strips on the surface of the helmet that help the cyclist to be seen on a dark road.
Safety – technical solutions for impact protection vary. What distinguishes them from each other is execution and efficiency.
Padding is the soft material on the inside of the helmet. It can be removable or not. The hygiene factor speaks in favor of removable padding, because it can be removed and washed.
The visor most often comes with an MTB helmet. It can be good when you need protection from the sun or rain to prevent water from getting on your glasses, but it is better if it is removable.

Everyone should wear a bike helmet!

There is an opinion that:

The helmet gives a false sense of security. A person becomes liberated and, in some cases, takes risks with an eye to the fact that at least his head will be intact. And this really happens. Another thing is that helmet manufacturers guarantee safety only in the event of a fall from a bicycle at a speed of no more than 15 km/h from a height of 1 meter onto a stationary and flat object. This is how they, of course, protect themselves from litigation. The helmet can withstand greater loads, but it is not omnipotent. A study was conducted in Australia that found that wearing a helmet helps with only 15% of head injuries. It sounds strange, but are we unique and cannot even get into this 15%?
Motorists have greater confidence in cyclists wearing helmets, and therefore subconsciously pass them at a shorter distance. British scientist (classics) Ian Walker found that the average convergence is 8.5 cm. And the number of those drivers who began to pass helmet-bearers at a distance of less than 1 meter increased by 23%.
In addition, the helmet allegedly makes it difficult to see, worsens aerodynamic properties, the head overheats and it is worse for thinking.

There is also legislative regulation. A bicycle helmet is required in New Zealand and Australia, in some areas of Washington state, in many provinces of Canada, and for children under a certain age - in almost all European Union countries and US states.

Categories and varieties

Modern bicycle equipment is made from innovative materials using technologies from other industries, including the space industry or defense industry. This fully applies to bicycle helmets, the main function of which is to protect the head from injury. Bicycle helmets have a variety of designs, and in their manufacture, foamed polymer materials are widely used, which most effectively resist shock loads and absorb impacts. The helmets are lightweight and have a specially designed ventilation system, which in some models is not limited to simple ventilation holes.

Today there are three types of protective bicycle helmets on sale:

racing ones, which are perfect for any trip on a bicycle, have good ventilation characteristics and an aerodynamic design - the road version is the most common and is equipped with a fully functional duct ventilation system;
mountain bike helmets (mountain bike helmets - MTB) have the highest degree of protection; their design is similar to road helmets, but unlike them they are equipped with a sun visor and have a more reliable and durable fastening system;
sports models of bicycle helmets belong to budget equipment and have minimal versatility.

Sports bicycle helmets are widely used when riding roller skates and boards and are divided into:

BMX helmets designed for stunt riding resemble full-face helmets in their design and functionality, but are additionally equipped with a sun visor;
track bicycle helmets have an oblong shape and an aerodynamic design, they do not have ventilation holes or slots, which significantly increase the aerodynamic resistance of this type of equipment;
Skating helmets have a rounded shape, small ventilation holes and, thanks to the use of fiberglass or carbon fiber in the manufacture, have increased strength.

Price

The lighter and more aerodynamic the helmet, the more expensive it is. Additionally, a cheap helmet may not have safety certification. When planning to make a purchase, check this with a consultant.

The figure on the check is also affected by the protection system: helmets with linear impact protection are cheaper than those that come with MIPS technology and the like.

You can buy the simplest helmet by spending a little more than a thousand rubles. If you are interested in more expensive helmets, there are models on the market for 20-50 thousand.

What is the choice based on?

It's not just your riding style that influences your choice of bicycle helmet. There are many other factors that must be taken into account. First, it’s worth understanding a little about the structure of bicycle helmets in order to understand the essence of the further conversation.

To create such elements of equipment, inelastic foam, or simply polystyrene foam, is used. The foam has a plastic coating on top, which makes a big difference. The strength of the helmet, the impact force it can withstand, aesthetic characteristics, and the ability to slide on asphalt depend on the quality of the plastic.

Inside there are softening pads that absorb some of the impact and make using the helmet more comfortable. The material of the pads must be hypoallergenic and breathable.

Cheap models use low-quality materials that are not able to provide the necessary level of safety, comfort and convenience. Therefore, you should not be tempted by cheap offers from unknown Chinese brands; after all, we are talking about your safety and health.

In addition to design features, it is necessary to pay attention to a number of characteristics, each of which has its own weight

The less weight the better. Believe me, you can feel every extra gram on your head. The maximum possible weight is 300 grams. Anything that weighs more should not even be considered as a potential purchase.
In order for a helmet to fit well on your head and not fall off during riding or training, it must be equipped with a fastening system and adjustment mechanisms. A bicycle helmet should be adjustable at the back of the head and fastened at the chin with two straps. It is better if these straps go through the entire structure of the helmet. In cheap models they are simply glued to the sides, which is not very reliable.
If you do not need high aerodynamic characteristics, then you should choose a helmet with ventilation channels. The degree of ventilation directly depends on their number and size.
The presence of a protective mesh is welcome, since such a simple element can solve the problem of small flying insects.
Elements with a reflective effect are necessary for those cyclists who love night rides. Without such an element, driving onto the roadway is dangerous.
We have already talked about internal gaskets before. Not only do they have to be there, but the quality of the material must also be at its best. When gaskets fray or tear, this is a real problem for the cyclist.

A helmet on a cyclist's head protects his head

Now, we hope, it has become more clear to you how to choose a bike helmet. But this is not all the information you need to have. Helmets are not universal in their sizes, so you need to know how to choose a bike helmet that fits. This is what the subsequent conversation will be devoted to.

Choosing a helmet according to size

This issue becomes most relevant if trying on a helmet is impossible (purchase via the Internet). You can find out the size of an item of equipment yourself; the procedure is no different. Take a centimeter and measure the head circumference. The centimeter should be located 2 cm above the level of the eyebrows. The result obtained is found in the corresponding table, where the corresponding helmet size will be indicated.

Properly worn bicycle helmet

Even during fitting, mistakes can be made. To prevent this from happening, you must adhere to the following rules:

The helmet should fit well and not slip off when moving your head.
If, when you open your mouth, the helmet presses slightly into the forehead area, it means that the straps are tightened correctly.
There should be some reserve left in the adjustment mechanisms, which will be useful in the cool season for a hat or balaclava.
The helmet should not be pulled up; it should cover the forehead, not open it.

Now you will know exactly how to choose a helmet for a bicycle and will not make mistakes. May your rides, training and travels be safe and comfortable.

Design

All of the above types of bicycle helmets have almost the same design, which we will look at below.

Frame

The body of a bicycle helmet is its main structure, which performs protective functions. It may differ in shape and materials of its constituent components, but the general principle of construction is the same.

Base. The base of the shell of bicycle helmets performs the main protective function. It softens the impact of a fall due to its deformation until complete destruction.

It is similar to foam plastic and can be made from polypropylene foam, polystyrene foam or polyurethane foam. Small particles of this material are pressed together in a special form under the influence of temperature. On more expensive bicycle helmets, the base is reinforced with nylon or carbon threads. Please note that this element of the bike helmet must be made exclusively from a single piece of foam, and not be glued together, for example, from two halves (as can be the case on Chinese models). The use of helmets with a glued base is unacceptable.
External covering. The outer covering can be made from materials called polystyrene, polycarbonate, or carbon fiber in more expensive models. It performs several functions: it increases the strength of the entire structure, thereby preventing accidental damage to the base layer, as well as punctures during a fall; and reduces the load on the cyclist’s neck when falling, due to the reduced friction force of the helmet on the asphalt (or other surfaces) due to its smooth surface.
Lining (removable and non-removable). The lining of a bicycle helmet also has several purposes. The first is to increase comfort due to the soft structure. The second is a reduction in impact force. Third, it helps to “fit” the helmet to the cyclist’s head (this is especially important for bowler hats that are not adjustable to the rider’s head). Plus, it absorbs sweat, which is very important in the summer. The lining can be removable or non-removable, and based on the latter property, we can conclude that it is better to buy a bicycle helmet with a removable one, since it is quite easy to remove and wash. It is usually attached to the base with Velcro.
Ventilation holes. These vents are located along the shell of the helmet and are designed to capture and properly distribute airflow to maximize heat transfer away from the cyclist's head.

I can’t say how true this is, but I found information somewhere that during wind tunnel tests it turned out that at a speed of about 30 km/h, cross-country helmets cool your head better than if you were driving without it . The other side of the coin is that the more holes, the less durable the helmet. Plus, it will be colder in winter.

Fasteners and auxiliary fittings

Any bicycle helmet is equipped with fasteners, straps and other additional accessories, the task of which is to ensure reliable fixation of the helmet on the cyclist’s head not only during a fall, but throughout the entire trip (since a poorly secured helmet can slide over the eyes, the back of the head or to the side) . It is advisable that the main straps be laid along the top of the helmet, and not attached to the sides (this increases the reliability of its fixation on the rider’s head). Every bicycle helmet must have a chin strap. It is advisable that it have a clasp that can be easily unfastened with one hand. On bicycle helmets with adjustment to the diameter of the head, a special rotating clamp is used (instead there may be a simple elastic band), which can be used to increase or decrease the volume.

When choosing, pay attention to all plastic parts, since components made from low-quality plastic may fail before the helmet itself.

Mosquito net

Typically, this element is located in the front ventilation openings to prevent insects from entering under the helmet. Installed on almost all children's helmets. This component is not required, but is desirable, because You must admit, it wouldn’t be very pleasant if some wasp got under the helmet.

Reflectors and mounts

To increase the safety of cycling at night, additional reflectors (reflectors) or mounts for various electric lighting devices can be installed on a bicycle helmet. They are also not mandatory, but it is better to take care of your safety (especially relevant on children’s bicycle helmets).

Stationary mounts for action cameras, such as Go-Pro, are rarely seen. Fortunately, they can be purchased separately and installed on a helmet without any hassles.

I would like to note that these mounts, which are glued to the helmet, do not fit well with country and road models. For these types, it is better to use a special mount with a strap.

Additionally

On some female models there may be a special hole for hair. This feature, as usually happens, leads to an increase in the price of the product.

How to wear a bicycle helmet correctly

An incorrectly worn helmet may not protect you during a fall or may simply interfere with normal riding.

The tightening of the fastening straps should not be too loose so that the helmet does not dangle from side to side, but also should not be overtightened, because this causes discomfort and impairs blood flow to the head. You should achieve a position where the helmet is as secure as possible, but does not cause discomfort. When adjusting the puff, move your head from side to side, lift it up, open your mouth, etc.
The position of the helmet should be strictly horizontal, and not shifted towards the face, back of the head or to the right/left.
In the autumn-spring period, you need to wear a bandana or hat under your helmet so as not to catch a cold. In winter, you can additionally place a plastic bag on the inside to cover the ventilation holes.

This video does a good job of explaining how to properly adjust the position of your helmet.

Piston installation

Insert a retaining ring into any boss of the piston pin. It is most convenient to insert the ring with small round nose pliers. After installation, check how well and tightly the retaining ring fits.

If the retaining ring does not cover the entire surface, but only a small part of it, replace it with a new one.
If the retaining ring does not lie tightly in the groove and dangles, straighten it a little

Lubricate the bearings of the lower and upper connecting rod heads and the piston pin bosses with clean engine oil. We put the piston on the connecting rod, orienting it with the “IN” mark to the inlet port; if there is an “arrow” on the piston instead of the “IN” mark, orient the arrow to the exhaust port. We insert the piston pin into the boss - orient the piston on the connecting rod so that the pin hits the connecting rod - install the pin all the way into the locking ring and secure it from falling out with the second locking ring.

We install the cylinder guide bushings on the studs and put on the gasket. It is advisable to place the gasket on the sealant, but without fanaticism.

How to choose the right size

When the bicycle owner has decided on the range of equipment and has selected the most suitable model for himself, he needs to clarify the size of the bicycle helmet. It should be borne in mind that many model lines of sports helmets are individually adjusted to the size of the cyclist’s skull. Equipment for riding mountain bikes and racing bikes is available in four size categories - from small sizes to very large. To determine the required size of a bicycle headgear, use a tailor's centimeter to measure the circumference of the skull at the level of “superciliary arches - temporal hollows”. This size will be decisive when choosing a specific size of a cyclist’s protective helmet.

The sizes of helmets currently produced, depending on the length of the skull circumference, are shown in the table.

If the measured size of the skull circumference is in the zone of boundary values, then the choice should be made on a smaller size category, because Over time, the helmet will “settle” a little.

Children's cycling hats designed for mountain and racing bikes are divided into two sizes “S” (45.0...50.0 centimeters) and “M” (50.0...55.0 centimeters). Most children's products are individually adjusted to fit the head of a specific user. Some samples have mosquito protection for ventilation slots and openings. In other respects, they are in no way inferior to specimens intended for adult cyclists.

Malfunction of IZh motorcycles - the engine runs intermittently

The main reasons for this malfunction are usually: clogged carburetor jets, water getting into gasoline, loose connections to the cylinders (air leaks), capacitor breakdown, oily or burnt breaker contacts, broken high-voltage wires and other reasons.

The most likely cause of cylinder failure is misfire. It is quite difficult to identify the causes of interruptions, so it is recommended to use the method of elimination, sequentially checking or replacing questionable ignition and power system devices.

Tips for choosing a helmet in a store

Since every head is different, you should definitely try it on before buying a bike helmet (that’s why we don’t recommend buying it online). Consider several models, because due to the different positions of the inner lining, some helmets will be more comfortable for you, and some will not. If you plan to ride with a helmet on, for example, to work, to the garage, or just on leisurely bike rides, then a cross-country or road bike helmet is best for you. If you want to bring a little extreme to your riding (a high-speed ride through a forest area or a steep descent from a small hill), then it is better to choose enduro. For jumping on the ramp and performing various tricks - only a bowler hat

Well, for downhill – full face. Choose bright models, as this will attract the attention of motorists, which will increase your safety. Plus, you should consider purchasing a helmet with reflectors or flashing lights. If you are purchasing a bicycle helmet for a child, you should not choose one “to grow into”

This is not a sweater. It should sit correctly on your head and not dangle on it. Some children's helmets have a diameter adjustment, just like adults'. You can take the one with the minimum value that matches the size of your child’s head, but in this case, be sure to try it on in the store. If you are buying full-face or bowler helmets, it is better to take a closer look at well-known brands of cycling equipment, for example, Met, Bell, Giro, BBB, etc. When buying a country helmet, you can save a little and take a product from a less famous company (since this helmet is still disposable) . But you should not buy Chinese models if you are not sure of their quality.

Installing the timing chain tensioner

If you have a 157QMJ series engine, do the following: unscrew the plug on the tensioner body; We insert a thin flat screwdriver into it and begin to tighten the bolt until the tensioner rod goes inside the body.

Without releasing the screwdriver while simultaneously holding the tensioner body, with your free fingers, insert the tensioner into the cylinder, screw it in with bolts, and only then release the screwdriver and screw the plug into place.

If you have a 139QMB series engine, then do this: unscrew the plug from the tensioner housing and remove the spring; push the rod inside the body; install the tensioner in the cylinder; insert the spring into the housing and screw in the plug.

After installing the piston, do not forget to adjust the thermal clearances of the valves and break in the engine.

Several recommendations for choosing a helmet

When choosing a helmet, it is extremely important not to make a mistake with the dimensions. You should not forcefully pull it over your head, because while driving it will not allow you to concentrate, because all your thoughts will revolve around the desire to quickly complete the trip and take it off quickly

On the other hand, the helmet should not hang on the head, since if it falls, the protective effect of such an accessory will be minimized.

And finally, remember that each cycling discipline has its own type of helmet that is ideal for specific riding conditions. Your safety and comfort of movement directly depends on its correct choice.