In this report I will write about converting a regular road frame into a regular road frame :), but with the ability to tension the chain.
The materials below will contain violence and scenes of a sexual nature. Please keep highway drivers, Cannondale fans and ASUS video card fans away from the screens.

The idea of ​​converting a frame from road to track has been in the air for a long time, and with the rise in the explosive growth of prices for track frames, it is inflated even more.

I came across the CAAD3 frameset on the forum, and if you take into account everything that came with it, the frame came out at a record price and the process began.

First of all, I inspected the frame and was pleased to note that most of the road trinkets were simply removed with screws. Here are the cable stops and the chainstay guide.

The native cock of such frames is specific and is also very convenient for alteration. I recognized the rear brake cable stops that were on the top tube as dangerous and carefully removed them with a file.

Instead of a permanent remodel, I opted for the option of removing my molding and putting the road bike back together.

Everything is more or less clear from the diagram

The idea was to cut a plate of the desired shape, 3mm thick, and another one, 3mm thick + dropout thickness... i.e. about 9mm. Next, in a thick plate, use a small hand mill to carve a notch in the shape of the dropout on the frame.

I know little how to plan, and even less I know how to wait, so the material used was whatever came to hand, namely two radiators from video cards. I was still a little afraid that there would be cavities with gases in them =), but it all turned out to be marketing. The material is soft enough to handle, but not plasticine either. Bending one radiator fin even with pliers is not as easy as it seems.

Everything was intended as a temporary option, but we know that... There is nothing more permanent than temporary.

In the final version there are no creepy nuts :).

This is the left one.

The sawed-off dropout is fully suitable for installing a wheel in the highway version. A few extra holes won't hurt it.

Well, here is the final version after 400 km. The placement of the screws seems chaotic, but it is dictated by the shape of the drops.

The flight is wonderful. I don't regret anything. I will also redo the next frame (and it 100% will happen), but avoiding those stones that I hit my head on the first time.

But in that article we ignored a very important question - how to choose a bushing for your fixed weight. So, let's begin:

Dropouts

There are basically two types of dropouts - vertical and horizontal. The former are increasingly seen on modern mountain bikes. There are no problems with chain tension; this is handled by the rear derailleur or a specially supplied chain tensioner.

What about a fixed weight? There are no switches or tensioners on it. That’s why you need a frame with horizontal dropouts; there are no problems with them. By the way, these are the ones that are classic for road, track and old mountain bikes. Most bushings for fixed weights are designed specifically for such dropouts; they are based on an axle with nuts on the sides. You can move the wheel by pulling on the chain and secure it. This system is simple and reliable (it’s the same on bmx’s).

Feather spacing

This is a very important point in choosing a bushing. There are several standards, the most popular of which are:

• 120 mm - used on older 5 and 10 speed bikes, and is also the most popular today for fixed weights
• 126 mm and 130 mm - less common, mainly on 6- and 7-speed road bikes
• 135 mm is a single standard for modern mountain bikes, but can also be used on road bikes

For front hubs the standard is 100mm (for fixed weights)

Measure the distance between the stays on your frame. If your bushing does not fit, you can use additional spacers, or apply mechanical force to the stays to change the distance (but this is not the best solution, especially for steel frames).

Number of spokes

Each hub differs in the number of spokes. There are also several standards here, the rarest of them is for 28 knitting needles. This wheel is very weak and it is not advisable to ride on one if your weight is more than 60 kg. The most popular standard for the number of spokes is 32, which is used on both regular mountain bikes and fixed weights. Another common option is 36, this amount increases the strength of the wheel (on bmx wheels with 36 spokes).

Flange height

There are no set rules here. The flanges are high, which increases the strength of the wheel (due to the use of shorter spokes) and low, which softens road irregularities (again, due to the length of the spokes).

Flip-flop hub or plain?

Most regular single speed hubs will not fit your fixed weight. The bushing will fit if the star is installed on a left-hand thread. This is related to the installation of a lockring, which you definitely need. A lockring is a threaded ring that secures and keeps elements from unwinding.

Of course, a regular bushing for a fixed weight has a minimalistic appearance, which looks very aesthetically pleasing and beautiful. . Perhaps this option is preferable for beginner cyclists who are not completely sure what they need and whether they want a fixed gear.

Chainline

This parameter, which seems nonsense at first glance, is important for professional racers, which is the distance from the front sprocket to the middle of the frame.

There are several standards you can try to achieve.

• Road bike - 43.5 / 45 mm
• Mountain bike - 47.5 - 50.0 mm
• Track, fixed weights - 40.5 - 42 mm
• Single speed - 52 mm
• Bicycle with Rohloff hub - 54 mm ()

Comparison table of the most popular bushings for fixed weights and single speed

Model	Type	Width	Chainline	Left	On right	Spokes
Ambrosio high flanges	Track	120	36	Fixed	Fixed	32
Campagnolo low flanges	Track	120	36	Plain	Fixed	28, 32, 36
Campagnolo C-Record	Track	120	35.9	Plain	Fixed	28, 32, 36
Gold Tech	Track	120, 130, 135	39.5	Fixed	Fixed	32, 36
I.R.O.	Track	120	36.0	-	Fixed/Free	32
Kogswell	MTB	135	45.3	Fixed	Fixed	32
Miche	Track	120	36.3	Plain	Fixed	28, 32, 36
On-One Full Monty	MTB	135	43.3	Plain	Free	32, 36
Phil Wood Track	Track	120, 126, 130	36.75	Plain/Fixed/Free	Fixed	28, 32, 36
Phil Wood K.I.S.S. Off	MTB	135	45.35	Plain/Free	Fixed/Free	32, 36
Shimano Dura-Ace 7700	Track	120	35.3	-	Fixed	28, 32, 36
Shimano Dura-Ace 7600	Track	120	35.4	-	Fixed	28, 32, 36
Sovos	Track	112	33.5	Free	Fixed	36
Spot	MTB	135	47.25	Plain	Free	28, 32, 36
Surly Track	Track	120	36.22	Free	Fixed	32
Surly 1 x 1	MTB	135	46.5	Free	Fixed/Free	-
Suzue Basic	Track	117-120	34.74	Free	Fixed	28, 32, 36
Suzue Promax (cartridge)	Track	120	35.0	Free	Fixed	28, 32, 36
Suzue Promax NJS	Track	120	35.0	Fixed	Fixed	28, 32, 36
Van Dessel	MTB	135	45.9	Free	Fixed	32
White Industries ENO	Track/MTB	126, 130, 135	39.1	Free	Fixed	28, 32, 36

steep slope

Singlespeed - a bike with one gear is popular in street and dirt. But thanks to some of its properties, it can also be convenient for cross-country in winter and in the off-season.

Of course, the first problem that needs to be solved before starting to assemble a singlespeed is what gear ratio to choose. General recommendations boil down to the fact that for driving in the city and on highways with not very hilly terrain, the ratio of the number of front sprocket teeth to the number of rear sprocket teeth should be 3 x 1. For hilly terrain and particularly difficult urban conditions, it is better to choose a smaller gear ratio - for example 2.5 x 1. For very rough terrain and off-road, the gear ratio 2 x 1 is best suited

The advantages of singlespeed are as follows:
- Less weight. The switches, shifters, cables with jackets, one or two front sprockets, and the cassette except for one sprocket are removed from the bike. This turns out to be quite a saving, especially if the equipment was not expensive.
- The system turns out to be more reliable. Due to the fact that the chain is relatively tightly tensioned, it almost never falls off. After any impact, you can be sure that in response to pressing the pedals, the bike will begin to accelerate, and not crunch.
- Cheaper. Even if you buy a special chain, sprockets and tensioner, it still costs less than a system with gears. This is if you buy new parts, and if you use dead ones, then it’s completely free, although with restrictions.
- Easier care. There is no need to clean off dirt and adjust switches so carefully. It’s easier to clean the chain then dirt and lubricate it. If you use dead components, then it is quite simple to add oil to the chain from time to time.
- And one more minor advantage. With one gear it is easier to navigate in a tense situation; you always know how hard to press the pedal.

Flaws:
- Poorly suited for rough terrain. Even if you use a bike only for street or dirt, it still becomes difficult to ride it from home to the riding area. And you can’t race cross-country at all - you’ll just kill your knees.
- In some cases, you will either not have enough speed, or you will have to press the pedals harder than usual. One pass, what can you do?

Singlespeed is usually made either on the basis of a frame with horizontal dropouts, or on a standard frame, with a special chain tensioner installed instead of the rear derailleur. In the case of horizontal dropouts, special stops are used that do not allow the wheel to warp. For dual-suspension systems, only the option with a tensioner installed in place of the rear derailleur is suitable, since the length of the rear stays changes when the suspension is in operation. However, there are frames with vertical dropouts that have an eccentric carriage unit, by turning which you can achieve normal chain tension. You should also remember that the planes of the front and rear sprockets must be at exactly the same distance from the central axis of the frame, otherwise the chain will constantly fly off, especially when shaking on uneven roads and when pedaling in the opposite direction.

Vertical dropouts
Vertical dropouts - with a groove located strictly vertically. In this case, there is no possibility to vary the position of the wheel, and even if the fastening is unreliable, the wheel axle will not change its position.
This type of dropout is mainly used in bikes with derailleur systems. Due to the fact that in this case it is impossible to regulate the chain tension by the position of the wheel, it is necessary to either use a speed switch with a tension system, or a separate external tensioner.

Horizontal and inclined dropouts
Horizontal dropouts allow you to vary the wheel position. This type of dropout is necessary for bicycles without a rear derailleur, since in this case the rear wheel axle must be movable to adjust the chain tension. When installing a wheel in horizontal dropouts, you need to be extremely careful and ensure that the bolts or eccentric are securely fastened to avoid subsequent distortion of the wheel due to chain tension.
Horizontal - usually on track frames. Inclined - on most singlespeeds. This is why dropouts need slope. Many non-track singlespeed frames allow the installation of a rear rim brake. But the wheel axle can be moved in the dropouts. Then the rim also moves. However, the brake should always reach the rim without readjustment. This means that the dropout slot must be made perpendicular to the top stay.

horizontal dropouts open to the rear. Sometimes there is a bolt in this unit to help align the wheel more accurately. Horizontal dropouts are a good solution, but they have a drawback: when installing the wheel and tensioning the chain, there is no guarantee that the wheel will be exactly the same as before. Often you will have to adjust the rear brake.

Sliding dropouts
The idea is clear in the picture

Eccentric carriage unit
There is a thread inside the frame to screw in a regular carriage. The eccentric assembly itself is inserted into the frame. The frame is sold already with it. The carriage cup of such a frame is much larger in diameter than usual, and there are no threads.

To tension the chain, the assembly is rotated in the frame and then secured with bolts. How exactly - there are possible options. The most common are bolts from below, perpendicular to the pipe wall. Typically these bolts are protected by short tubes welded to the bottom bracket shell.

Frames with eccentric dropouts
Although they are still considered strange even in decent countries, the emergence of several different brand standards indicates interest in such a solution. Moreover, in some versions it does not look as bulky as sliding dropouts.

This option allows you to avoid reinstalling the disc brake caliper when installing other chainrings on the singlespeed.

Trek has shown that the eccentric dropout works well with a detachable chainstay and chainstay joint (to accommodate a sling). Of course, a regular bushing for the chain also comes in here.

On bicycles with a gear shift system, the rear derailleur is attached to a holder on the rear right dropout, or to a special overhead bracket - a cock.

Holder
part of the dropout with a special fastening. The holder can be built-in or can be replaceable. In this case, it can be called a “rooster”.

Dropout with built-in holder, regular holder and dropout with built-in holder ("cock")

Chain tensioners They are usually used on vertical dropouts. A part similar to the rear derailleur is used to adjust chain tension. Some tensioners have one pulley, some have two. Tensioners are mounted mainly at the site of the rear derailleur. But there are also devices that are attached to the feather, to the seat tube, or even just anywhere.

Halflink chain (or 1 halflink in a standard chain) A chain with not ordinary links, but “half-links”

There is another option like phantom star, but, from my point of view, for its appearance it is on the verge of fantasy. The main thing and the worst thing is that under load the upper branch of the chain straightens, shifts the phantom sprocket down - and the branches of the chain simply stretch like shoelaces. If you break it down into strengths, you can see that icy wires stretch and break in about the same way.
Everything is so bad that when you press the pedals, you feel not the emphasis on the pawls on the rear hub, but the springy reaction of the chain. You stop pressing - the elasticity of the chain returns the phantom star to where it is in the photo

When riding, the load on a chain with a phantom sprocket is much greater than in any imaginable case.

However, that's not all. As practice shows, a singlespeed can be made on the basis of a regular hardtail, and without investing practically any money in it! For this you need a front sprocket, a rear sprocket and a chain (which is generally obvious). Moreover, they may not only be not new, but even very worn out, one might even say killed. On a conventional system with gears, they can no longer be used, since in the best case, the gears will shift poorly, and the chain will completely kill the sprockets, and in the worst case, it will simply slip over the sprockets. But on a singlespeed without a tensioner or on a frame base with horizontal dropouts, it simply has nowhere to go. And it works! It crunches and jingles, but it works, completely free. You may well have damaged parts lying around if they weren’t thrown away at one time, and it’s not difficult to find them for symbolic money. Thus, you don’t have to worry about drive wear, which, by the way, is especially important in winter with its eternal salt.
When assembling a bicycle, you need to select the sprockets as carefully as possible so that the chain is properly tensioned. It might be worth using a 22 tooth front sprocket, it will also reduce weight. You can also install a regular rear sprocket, but the hub drum must be strong enough, and it must be made of steel. If this is not the case, then you can assemble 3-4 stars from a standard cassette with steel pins holding them together. That is, to put it simply, take not one star from a cassette, but several. At the same time, it is worth making sure that the chainline is normal, since this is absolutely not difficult to do. It is enough to determine by eye the position of the driven sprocket at which the chain bends minimally. If the leading sprocket is 32, then the driven one should be in the place of the third or fourth sprocket of the cassette, counting from the smallest one. To prevent the driven sprocket from moving around the drum from side to side, use standard spacers between the sprockets from any cassette.

The chain runs with only a slight misalignment.

Of course, such a system has significant drawbacks.
- The chain wears out during operation and stretches. For killed sprockets and chains, this is not important, except that it starts to crunch a little. But the problem is that, as it stretches, the chain sags, and, therefore, with a certain wear, it begins to easily fly off the sprockets. This means that you lose the important advantages of singlespeed. You can place larger diameter stars next to the working stars, but this, of course, will not solve the problem. The solution is to look for the chain again.
- Since the chain must be very tensioned during installation (much more than on a system with gears), you may have to use sprockets that are not what you would like. For example, you want to put 32 teeth in front and 16 in the back, but the chain cannot be tensioned - it either sags or is so short that it cannot be connected. But I repeat once again, this problem can be solved if you have skillful hands, horizontal dropouts (well, or all kinds of eccentric carriages) and chain tensioners

A bicycle fork is a multifunctional supporting part (or mechanism) of a bicycle steering that holds the front wheel on the bicycle and directly connects the wheel axle to the steering wheel.

The main functions of various plugs include:

• turn the wheel exactly to the steering angle;
• maintaining the exact trajectory of the wheel due to the torsional rigidity of its own design;
• perception of loads when braking a bicycle with the front brake;
• holding the front wheel axle;
• damping of vertical vibrations of the front wheel during high-speed riding over uneven surfaces (in the case of suspension forks), ensuring high-quality damping and quality of bicycle control;
• ensuring the safety of cycling due to the sufficient strength of its own design, designed for a specific type of use.

Bicycle fork device

The components of the fork are shown in the figure.

• Stock- the fork axle, which is rigidly pressed into the fork crown. The stem is inserted into the steering tube of the bicycle frame and is firmly held by the stem from above. The rod can be steel, aluminum or carbon.
• Crown- a part of the fork into which (for single-crown forks) the rod and both legs of the fork are pressed (for double-crown forks, the upper crown is put on the rod under the stem and holds the legs). The crown is made from cast aluminum, followed by forging (all middle and high class forks) or carbon fiber (if the stem is also carbon).
• Legs(for rigid forks - “feathers”) - parts of the fork with a tubular profile that are either connected to the wheel axle directly (for rigid forks) or telescopically moved inside the trouser structure (for shock-absorbing forks). The legs of the suspension forks partially contain: external fork adjustments, springs and dampers.
• Trousers- a part of a suspension fork, consisting of two “cups” of a tubular cross-section, connected in most cases to each other by a gorilla in the form of a single part (does not apply to inverted forks). The legs of the fork slide inside the pants. Pants are made from cheap aluminum alloys (lower-end forks) and expensive durable aluminum alloys (some custom hardcore freeride forks); aluminum alloys with magnesium or multi-layer construction made of aluminum alloys and carbon fiber (some high-end forks up to downhill ones). Most forks have magnesium alloy pants with aluminum.
• Dropouts- wheel attachment points - usually represent a single part with the pants. However, if the pants are carbon, the dropouts can be made of aluminum alloy. Select fork models have stainless steel dropouts, which eliminates the common problem of magnesium corrosion in this area. Dropouts come in open (9 mm axle) and closed (15 mm and 20 mm through axles).

Bicycle fork materials used

Rigid forks are usually made of steel, aluminum alloys, carbon fiber and sometimes titanium.
Aluminum and steel forks- the simplest and cheapest to manufacture. At the same time, aluminum ones are considered the worst to use, because they transmit vibrations more strongly to the hands. They are also potentially not very reliable (due to the possibility of rapid metal fatigue). Steel forks are more reliable, but a little heavier.
In high-speed road bicycles, starting from the middle level, they are widely used carbon forks, and their rod can be either aluminum (cheaper) or carbon (lighter and more expensive). Dropouts on inexpensive carbon forks are usually aluminum. Carbon forks are also available for mountain bikes, as well as for downhill.

Titanium forks, available in our country, are manufactured by Rapid and others, on single orders. The design features of titanium forks depend entirely on the wishes of the customer.

Suspension forks use a variety of materials in different combinations, depending on the class of the fork. In general, aluminum parts are more expensive than steel parts, and carbon parts are much more expensive than aluminum parts, and are the hallmark of ultra-expensive, high-end racing forks.
Suspension fork legs can be made from the following materials:
Steel followed by chrome plating of the working surface - the lowest level fork.
Aluminium alloy- medium and high level forks. Various types of work surface coatings are used:

• hard wear-resistant varnish of beige color,
• hard, wear-resistant black Teflon varnish,
• Nickel plating

Geometric dimensions of bicycle forks

• Overall fork length. Affects the geometry of the bike. When replacing a fork (especially a shock-absorbing one with a rigid one), you should take into account the difference in their lengths. In general, it is not recommended to install a fork with a length that differs by more than 20 mm from that recommended by the manufacturer.

• Overall fork offset. It consists of the overhang of the crown and the overhang of the dropouts. It affects the handling of the bicycle - the greater the reach, the higher the stability when moving in a straight line, but the worse the handling. The standard value is around 45mm for mountain bikes and around 35mm for hybrids.

For suspension forks

Fork travel. The longer the travel, the larger obstacles the fork can handle -> the more impacts the fork can absorb -> the higher the speed can be on jumps -> there is less opportunity to fly over the handlebars, since the front of the bike is higher than the rear -> a comfortable position for the rider at high speeds going down the slope. The shorter the stroke, the -> lower the center of gravity of the bike -> higher control accuracy -> less fork swaying when pedaling hard -> better suited for uphill riding. It is believed that the smoother the road, the less fork travel should be. Typical travel values, depending on the intended driving style, are:

• Hybrids: 50-70 mm.
• Cross country: 80-100 mm.
• Cycling, rides, adventure racing: 80-120 mm.
• Dirt: 80-100 mm.
• Marathon/enduro/trail: 120-150 mm.
• Freeride: 180-250 mm, single crown, double crown, double crown inverted forks.
• Downhill: 170-200 mm, double crown forks.
• Hardcore freeride: 250-300 mm, inverted double crown forks.

Leg diameter. The diameter of the legs is calculated depending on the load of the fork and affects the life of the guide bearings in which the fork legs move. The more rigidly the fork is used, the larger the contact area between the leg and the guide bearing is required to reduce friction between them and increase their service life. The diameter of the legs also affects the overall weight of the fork and torsional rigidity.

Leg diameter values ​​for existing bicycle forks:

• 28mm - old KK forks, low level forks,
• 30 mm - some light KK forks,
• 32 mm - forks for CC and light extreme sports (the most common size),
• 36-40 mm - common forks for downhill and freeride.
• 37-42 mm - hardcore freeride (forks from Avalanche Downhill Racing MTN series and forks from Risse racing)

Rigid forks

In such forks, shock mitigation occurs to some extent due to the elastic deformation of the material of the legs; the remaining part of the shock falls on the tires and the biker’s hands. They are used on bicycles, mainly intended for road riding. They are produced by a huge number of companies, ranging from completely unknown Chinese ones to global brands such as DT Swiss.
Rigid forks do not allow you to develop high speed on uneven roads, but they also have a number of advantages:

• High reliability;
• Insensitivity to frost, salt, dirt;
• There is no need for maintenance;
• Very favorable cost/weight ratio: a rigid fork is 1-1.5 kg lighter than a shock-absorbing fork for the same money;
• Virtually unlimited tire thickness;
• Metal forks usually have holes for installing a rack, a full fender, and sometimes additional bottle cages.

The materials used in the manufacture of rigid forks are listed in ascending order of price:

• Chrome-molybdenum steel. The weight of the fork is 1000-1200 g, which is close in weight to a top-end shock-absorbing one, but the price is the lowest, about 60 €.
• Aluminium alloy. Oddly enough, the weight is not much different from a steel fork - about 950 g. The price is higher, about 75 €. The advantages include a wide range of colors.
• Carbon. There are several types:

1. With aluminum components (dropouts, crown, stem) - have an average weight (about 800 g) and price (120-150 €);
2. All-carbon ones are the lightest (from 300 g), but the price starts from 170 €, plus you need to be careful when working with a carbon rod. There are both with a pronounced crown and without it. By saving on such a fork, you can easily buy a house in Belgorod!

• Titanium alloy- rare forks, produced mainly by Rapid. Weight is about 600-850 g, depending on a number of factors, the price is high, from 170-200 €. The strength and reliability of all these forks is sufficient even for racing. However, it is natural that ultra-light carbon forks require more care than heavy steel ones - for example, carbon forks may have more stringent requirements for the installation process and for the maximum weight of the biker.

Suspension forks

Used on bicycles intended for use on uneven terrain, off-road, high-speed use on uneven terrain, extreme use, etc. Serve two purposes:

• Improves control over the bicycle at high speed - the wheel better maintains its trajectory and grip with the ground; absorbs shocks that occur on the wheel during extreme use and jumping.
• Increases the comfort and safety of high-speed driving.

One-legged forks

These are forks that have a cantilever mounting of the front wheel.

Single-legged forks come in three types:

• Telescopic (Cannondale Lefty)
• Lever (USE S.U.B Anti Dive)
• Rigid (Cannondale, Rapid)

Features of single leg forks:

• High price;
• Some models require the use of special front hubs;
• Inability to install rim brakes;
• Possibility of changing the front tire without removing the wheel.
• It is impossible to remove the wheel without removing the brake caliper.

Plug Compatibility

Disc brakes. As a rule, modern suspension forks are designed to install disc brakes with a rotor with a diameter of 160 mm using a Post Mount (less commonly an IS Mount). Other standards and/or rotor diameters are supported via adapters. Forks for extreme disciplines may be initially designed for 180 or 203 mm rotors - in this case, the use of smaller rotors is not possible.

Rim brakes:

• Vibrations and cantilevers- a number of fork models have the ability to install such brakes using stationary or removable break bosses.
• Clamp brakes- used on road bikes.
• FirmTech- This is the standard installation of Magura hydraulic rim brakes, supported by separate forks.

Dropouts

The forks use different dropout standards:

• QR9- standard thin axle with eccentric (or bolt on older bikes) clamp. The most common standard, on all bicycles in the lower price range without exception and on most non-extreme ones.
• QR15- plug-in hollow axle with a diameter of 15 mm, with eccentric fixation. It appeared relatively recently, the standard is promoted by Shimano and Fox, and now almost everyone has joined.
• QR20- plug-in hollow axle with a diameter of 20 mm, with eccentric fixation (for extreme disciplines).
• 20mm Thru-Axle- plug-in hollow axle with a diameter of 20 mm, fixed with bolt clamps (extra durable, for extreme disciplines).

The larger the axle diameter, the higher the torsional rigidity of the fork - so, in pursuit of increasing rigidity, the QR15 standard is being massively introduced in cross-country bicycles, where previously only the QR9 standard was used.
Depending on the type of dropout, a corresponding bushing is required, and bushings for a 15mm or 20mm axle can be converted to work with a thinner axle using appropriate spacers.

Rod diameter

Designated in inches depends on the existing frame and steering column. Older threaded steering columns used the 1″ standard.
Standards for threadless steering columns:

• 11/8″ is the most common standard.
• 11/2″ is Cannondale standard.

Tapered rod 11/8″-11/2″ (English tapered) - is actively being introduced into modern mountain bikes. Requires a special steering column and is not compatible with non-integrated steering columns.
The larger the rod diameter, the higher the strength and rigidity of the fork-frame connection., but this may cause weight gain. A frame with a thick stem stem can be used with a thinner stem by installing a matching steering column (or spacers into an existing steering column), such components are called "Reducer". Also, not so long ago it became possible to install a fork with a tapered rod in an 11/8 head tube. To do this, you need to use an adapter headset, such as the Nukeproof Warhead 44IETS. Compatibility is achieved by moving the lower bearing outside the cup into the elongated steering cup.

The topic of suspension forks is worthy of an article! Stay with us! Subscribe to updates!

First we need to make it clear that there is confusion between these two concepts.

The eccentric is just a way to tighten the nut. I won’t describe the mechanism, I think everything has been presented. And in relation to bushings, this is a method of fixing the bushing in the dropouts of the frame or fork, or fixing the axle. But it also includes the meaning of an axis, which is also not entirely true. Let's figure out what's what.

These are the axles of the front bushings

Integrated. So to speak, an axle with an outer diameter of 9mm and an inner diameter of 5mm (first picture). A 5mm tie is inserted into it, which everyone calls an eccentric in the English version, quick release (QR). By the way, there is also an option for a hexagon (second picture), without an eccentric. Designed for forks with open dropouts.

photo 1 photo 2

Internal. A bushing with an internal axle with a diameter of 12mm, the ends are machined so as to fit into open 9mm dropouts. Fastened with 5mm bolts or eccentric.

Example SUN Ringle:

Axleless. Such a bushing has a hole of 9mm, 15mm or 20mm in diameter, into which a 9mm, 15mm or 20mm axle is inserted, respectively.

Hexagon or quick release. For example, 9mm eccentric, 9mm RWS thru bolt from DT Swiss

or with a 20mm Maxle axle from RockShox. In the English version 9/15/20mm thru axel.

The 9mm axle can be mounted to the same open dropout forks as the first two options. And for 15mm and 20mm, you already need so-called forks for a 15mm axle

and 20mm:
There are also forks for 9mm axles, for example, some Marzochi:

15mm axle on FOX fork

Rear hub axles

• Again, an integrated hollow axle with an outer diameter of 10mm, an inner diameter of 5mm (http://www.chainreactioncycles.com/Images/Models/Original/8200.jpg), under the same 5mm eccentric (QR) or hexagon (http:// www.chainreactioncycles.com/Images/Models/Original/26621-2.jpg), which acts as a fastener.
• Hub for 10mm bolts (http://www.chainreactioncycles.com/Images/Models/Original/33673-2.Jpg): there is an axle inside, but it does not extend beyond the edges of the hub, as in the case of an eccentric, but has a thread, into which a bolt with a diameter of 10 mm is screwed in on the right and left. In English it can sound like bolt up or bolt on.
• Bushing for 10mm axle (http://www.chainreactioncycles.com/Images/Models/Original/28787.jpg). Hollow inside, without its own axis, a 10mm axis is inserted into them, which serves as a lock. It is tightened either with a nut or, again, with an eccentric (as an option RWS thru bolt (http://www.chainreactioncycles.com/Images/Models/Original/21670.jpg) from DT). In the English version, 10mm thru bolt axel (the word bolt may be missing).
• For 12mm axle (http://www.chainreactioncycles.com/Images/Models/Full/7568.jpg). Similar to the previous option, only the axle diameter is 12mm. Again, there is a quick release option, such as the Maxle (http://www.chainreactioncycles.com/Images/Models/Original/27736.jpg) from RockShox. English version - 12mm thru axel.
• Under 10mm (http://www.rohloff.de/typo3temp/pics/fc872e0176.png), 12mm (http://www.chainreactioncycles.com/Images/Models/Original/12151.jpg) or 14mm (http: //www.chainreactioncycles.com/Images/Models/Original/34011.jpg) nuts. The axle is long and comes out of the dropouts; nuts are screwed onto it, which secure the bushing.

The bushings also differ in width, that is, for different distances between the dropouts.
Front bushings for eccentric, 9mm and 15mm axles - 100mm, for 20mm axles - 110mm.
Rear: for an eccentric - 135mm, for a 10mm axle and bolts, as well as a 12mm axle, there are both 135mm and 150mm. For 14mm I know only for 135mm, moreover, single speed (without the possibility of installing a cassette).

As for when the axle is stronger - in theory, always, since eccentric axles are usually not for the entire dropout, but for half. And the axle also better fixes the bushing and increases the torsional rigidity of the fork/rear triangle - this is already a fact.