What is suspension travel on a bicycle? How to choose a mountain bike. Suspension Maintenance

You've probably heard about shock absorbers. We are more than sure that your bike even has one of them installed - most likely a front fork. What if you have more than one bike?! Then the chances that on weekends or much more often you are driving a steel (we joked - aluminum!!!) horse with two shock absorbers really increase. And even if you’re just thinking about taming a freeride monster, you’ve probably heard (or guessed it yourself) that the suspension requires not only careful maintenance, but also ADJUSTMENT. On the one hand, many professional racers change the pressure, install springs with different stiffness and recalculate the clicks of the tuning knobs after each training ride. On the other hand, some people tune the bike only for a specific trail. And some people only tune the bike once!!!

We will tell you how to adjust the suspension of a modern bicycle below. First - about how to evaluate whether the settings are made correctly?!

The “yard” express method will allow you to instantly assess not only the correctness of manipulations with the suspension settings, but also the general technical condition of the bicycle. Lift the bike by grasping the saddle and stem. Let go so that it “flops” to the ground with both wheels at the same time. A malfunction can be detected by sharp ringing, squeaks, shocks in the suspension or other “extraneous” sounds. The shock absorbers “must absorb” part of the landing energy, that is, the steel horse must “spring its legs” and remain on the surface. And if the bike bounces like a ball, then the settings are incorrect. Then, on uneven surfaces (or worse, on a steep descent) with the rider he will jump higher, trying to kick you in the butt with the saddle and throw you forward on the descent or put you on your side in a fast turn. Before you know it, you'll find yourself on the ground so quickly!

If you own a serious sports racing car, we recommend conducting two tests. The first is that you don’t accelerate very much and, standing on the pedals (this is how you usually drive over bumps), you drive over the bumps. You can place a board or a thick stick on smooth asphalt. A bump or root on a flat path is also quite suitable. With your feet and hands, feel the center of gravity to see if there is a sharp upward push from the suspension?! There should be no springy upward rebound. The impact from the unevenness should be smoothed out by a damper.

The second test is to drive off the curb at speed. Try to reach such a speed that both wheels touch the asphalt at the same time. There should be no rebound of the suspension after landing in this case either. Moreover, the swinging (creak-creak-creak) of the suspension. A bicycle is not a spring bed. With this test, in addition to all of the above, an imbalance in the operation of the front and rear suspension is revealed.

The starting point in tuning a mountain bike's suspension is to adjust the shock absorber (suspension) sag. This is the difference between the length of the shock absorber without a rider and the length of the shock absorber with the rider riding the bike. It is very important to take exactly the position you usually take on a bicycle. If you ride downhill more often, it is better to stand on the pedals and place your “fifth point” (center of gravity) where it usually is. It is strictly forbidden to lean on your foot or remove your hand from the steering wheel! The weight distribution between the front and rear wheels will change. Have someone measure the length of the inner tube (axle) between the fixed boots and stops. You can't do without help here. Even if you take measurements using a plastic clamp or a rubber ring on the “leg”, there is one BUT. When you sit on a bicycle, you push the “mark” much further than in a static position. This method will only help you see whether you are using the entire stroke of the shock absorber, but this is after...

For vigorous pedaling over rough terrain, sag should be within 10-20% of the maximum suspension travel. Naturally, athletes make their settings tougher. For extreme disciplines, subsidence is set within 20-30% or even more. Some professional racers leave half the travel for a rainy day, so the wheel seems to stick to the bumps.

It’s easy to set sag on air shock absorbers - pump air into the main chamber if it sags too much. If there is insufficient subsidence, reduce the pressure. Before doing this, don’t be lazy, read in the manual what the recommended pressure is for your weight and riding style. You need to dance from these numbers, like “from a stove.” The main thing is to remember the maximum pressure for which the insides of the expensive device are designed. It will be better if it is not exceeded.

Spring-oil shock absorbers are equipped with springs designed for the “average” cyclist. Therefore, light riders or, conversely, heavy ones, most likely end up buying a new spring. If you are riding in different conditions or you like to land hard, you may need more than one spring.

For suspension forks, springs are most often sold in pairs, and the settings in both legs are made the same. But the principle remains the same: if your legs sag too much, tighten the spring to make it stiffer. It sags very little - unscrew it, loosen it. On the fork, the adjustment knobs are located at the top and have limiters. If you don't twist them only with your hands, you won't break anything.

There are no stops on the rear shock absorber, so there is a risk of breaking the spring or stop nuts. Remember one thing: NOT ONE rear shock absorber spring can be compressed (from a free state) by more than 10 - 15 mm! The spring stiffness is set once and for all during manufacturing. By squeezing it tightly, you will load the stops, the shock absorber rod (which will certainly lead to breakage) and weaken the spring.

The instructions for the shock absorber from a well-known manufacturer of racing shock absorbers say: if you need to tighten the spring more than two turns, buy a slightly stiffer one. It is quite clear that the spring should not dangle, the thrust ring serves as a stop, otherwise, if it gets skewed on the shock absorber rod, it will break itself and disfigure everything around it.

Only on the cheapest shock absorbers you will not find other settings. Check the manual for your fork (it's never too late!) and find the rebound adjustment knob. First you need to completely “unscrew” it. That is, to make the rebound the fastest. Don’t forget about symmetry in the settings; if you unscrew the right knob, unscrew the left one too. Then, adding half a turn (everything is symmetrical: half a turn to the left, half a turn to the right), we vigorously push the steering wheel down, squeezing the fork. The steering wheel should bounce as quickly as possible, but there should be no push (“kickback”) to the hands.

The rebound of the rear shock absorber is adjusted in exactly the same way, only you compress the suspension with your feet while moving. There should be no kickback or bouncing, otherwise the wheel will slide only on the tops of bumps off-road. Don't be alarmed if you turn the rebound adjustment knob halfway, maybe more. Too slow a rebound and lag are also bad. At high speeds, during a series of impacts, the suspension “will not have time” to straighten and with each impact it will become more and more rigid.

On long cross-country rides and races, you should not notice any swaying forward or backward. The stiffness, rebound and compression of the front fork and rear shock should be identical. If you are planning to ride only downhill, it is useful to adjust the rear shock absorber a little softer, with a slightly slower rebound, because rear wheel There is less load on the slopes. On a flat surface, with these settings, a “soft tail” feeling appears. Accordingly, the sag of the rear suspension may be slightly greater. Five years ago, most downhill bikes had 20-30% more rear suspension travel than the front.

If you're lucky enough to own a bike with expensive, modern damping systems, be sure to experiment with compression adjustments. This setting changes the shock absorber's compression resistance. Depending on your riding style, riding location and preferences, you can install a kind of “pedaling platform” (reduce suspension sway during vigorous acceleration) or reduce the likelihood of breakdown (hard compression of the suspension to the limit). With strong compression resistance, the suspension handles large bumps and rocks better and works well on hard landings. On small irregularities, it will not have time to operate. Grip will be poor and braking will be choppy. With low compression resistance, the shock absorber will “work” perfectly over small roots and stones, but swipe- will miss.

When trying different settings, write down the number of clicks or turns of the handles (there is more pressure!), this will make it easier to understand what is happening and why, because some shock absorbers have five or six different adjustments. Don’t flatter yourself that you made the final adjustments today. If your mood changes, your driving style changes, or you get carried away to other tracks, you can be sure that you will want to play with the adjustments again.

Congratulations on purchasing your new Transition bike with GiddyUp suspension. To get the best performance from your bike and get the most out of your riding experience, please read the GiddyUp Basic Suspension Setup Guide.

There are no 'absolute' set-piece settings, and our recommendations may vary slightly depending on various factors such as air temperature, the accuracy of your pump gauge, and riding style. It is important to maintain consistent suspension settings; once you have adjusted it, check the settings every time you ride. Keep an eye on your bike's settings, and the longer you ride at these specific suspension settings, the more you'll get a feel for how any settings changes affect the bike's performance.

It is impossible to set up the suspension perfectly the first time. These instructions are only a starting point and point you in the right direction for setup. We will try to help you understand the basics of how your bike's suspension works and settings. When setting up your suspension, remember a few important points:

• Remember to move the rubber ring on the shock rod towards the boot to see how much travel your suspension has on the trail. Regardless of riding style, the ideal setup should be for the suspension to engage the entire travel once or twice per descent. If this does not happen, you are not using 100 percent of your suspension's capabilities. But suspension breakdowns should be expected. If the suspension engages the entire travel too often, it means that you have not inflated the air spring enough or have not adjusted the compression damping correctly, this will affect the ride quality. Activating the suspension for the entire stroke will move the indicator o-ring to the very end of the shock absorber rod or completely push it off the rod.

The suspension doesn't work all the way. The suspension operates throughout the entire travel.

• In general, we recommend setting the sag a little more than on other trail bikes, so don't be surprised by the numbers in the table. We have thoroughly tested everything and determined that these settings the best way Suitable for most riding styles.
• When setting up and checking the suspension sag, make sure the tires are inflated to operating pressure and the bike is sitting on a level, smooth surface. Wear all the gear you would normally wear and a fully packed backpack, making sure to fill your hydration pack with water. In the quick bike setup chart, “rider weight” is exactly what you weigh when fully equipped.


• Try to always use the same high pressure pump to adjust the air springs. Even two pumps of the same model may be calibrated differently. You should not expect that the pressure value obtained on your pump for an ideal sag will be universal when pumping with any other pump.
• Your bike is equipped with a Rock Shox rear shock with a Debonair air spring. Models with Debonair differ from conventional Monarch shock absorbers in the increased volume of the negative chamber. For every major change in pressure in the air chamber, it is necessary to compress and release the suspension several times, then check the established pressure. If you skip this step, the pressure gauge readings will be incorrect. After increasing or decreasing the pressure in the shock absorber, disconnect the pump and pump the suspension 5-10 times to equalize the pressure in the shock absorber chambers, then reconnect the pump and check the pressure gauge readings. It's quite a fun activity, and everyone around you will think that you take your suspension tuning very seriously.

Checking the sag of the rear suspension and shock absorber
1. Make sure all compression settings are in the open (minimum) position.
2. Set the shock absorber rebound speed adjustment to a relatively fast position. Ideally, if you compress the suspension with your hands on the saddle and sharply pull the saddle up, the wheel should not have time to leave the ground (before the shock absorber is fully released). Try not to adjust the rebound too slowly. At this stage, the faster the better, a more open and faster rebound setting will allow the shock to handle bumps better.

Indicator o-ring near the shock absorber boot.

3. Lift the red indicator o-ring up the rod until it contacts the boot on the shock absorber air chamber. Sit in the saddle and move around on the bike a little. Then bend down and lift the o-ring up towards the shock absorber boot again. Next, sit on the bike in a neutral position and lift both feet off the ground. Carefully get off the bike, try not to further compress the suspension.
4. Check where the red O-ring remains on the rod.

Correctly configured sag 35%.

5. This is the sag of your suspension. If the shock absorber does not have a sag scale, use a ruler to measure: sag will be determined as the ratio of the distance of the o-ring from the boot to the full stroke of the rod (in percent).
6. If the sag is greater than the recommended value, pump up the air spring a little. If the percentage value is less than the recommended one, you need to release excess pressure from the shock absorber.


Adjusting the sag of the shock absorber
1. Screw the pump to the shock absorber inflation nipple. If you have a digital pressure gauge on your pump, make sure it is turned on before you connect the pump to the shock. If your shock's sag was slightly less than the recommended value, you will need to bleed some air from the shock's air chamber. If you miss the sag by just a little, drop 5-10 psi. If you miss the adjustment quite a bit, you can immediately drop 20-50 psi. To relieve pressure, use the dedicated air release button, pressing it gently and slowly.
2. Having adjusted the pressure, disconnect the pump from the inflation nipple and pump the suspension several times to equalize the pressure in the positive and negative chambers. Repeat the steps for checking the sag, if the value still does not correspond to the recommended value, adjust the pressure in the air spring again.
3. Having set the correct pressure in the shock absorber, you can get on the bike and go for a ride. Don't forget to screw a protective cap onto your shock's inflation nipple and bring a high-pressure pump with you to fine-tune your suspension when riding on the trails.

Adjusting the shock absorber rebound speed
1. Within reason, rebound speed adjustment is a personal preference for the individual rider. Rebound speed also depends on the air spring pressure in the fork or shock. The lower the spring pressure, the less noticeable the effect of each click of the rebound adjuster on the suspension compression rate. For example, at a particular rebound adjuster position, the damper's spring rate will be less at 140 psi than at the same adjuster position at 170 psi. It is important to remember that the rebound speed adjustment clicks are always counted from the fully closed (slowest) position of the adjuster, and never from the fully open position.
2. A good guideline for initial rebound adjustment is the following procedure. Stand to the side of the bike and squeeze the fork and suspension with your hands, then try to lift the wheels off the ground. You shouldn't be able to do this until the fork and shock have fully extended their travel.
3. If the rebound is too slow, the shock absorber will not have time to expand to its original state after being compressed by a bump or impact. This phenomenon is called “suspension folding”, it is especially noticeable during a series of repeated impacts of medium strength; the suspension seems dull, and sometimes it may even seem that it has stopped working. In this case, turn the rebound adjuster counterclockwise to increase the damper release rate.
4. If the rebound is too fast, you will feel like you are riding on a spring. The rear wheel will be thrown off each bump, bouncing erratically over a series of obstacles as the suspension springs back too quickly after compression and the wheel hits the next obstacle with even more force. In this case, you need to turn the rebound adjuster clockwise, slowing the shock's release rate until you feel the suspension is working as it should.

Now let's go for a ride
Check your settings and make sure everything works as it should. Before heading down the trail, move the indicator o-rings to the boots on the shock and fork (at the beginning of the stroke). After going down the trail, look at how much travel your suspension has, the position of the rings on the fork leg and shock absorber rod will indicate the maximum compression of the suspension. This The best way find out if you are using the full potential of your bike's suspension. If you look like this guy in the photo, you've successfully tuned your Transition's suspension.

Giddy Up Suspension Quick Tuning Chart

Example: A 170 lb rider might start with a shock pressure of 160 psi on the Patrol, 175 psi on the Scout, and 155 psi on the Smuggler. Remember that these numbers are not dogma, and to set up the ideal sag you may need to pump a little more or a little less. However, if you've measured everything correctly and set up the bike within the limits we recommended in the instructions above, you're ready to hit the trails.

We haven't made a detailed chart for every rider weight because there are so many variables that affect the settings, different types of shock absorbers, differently calibrated pumps, environmental conditions, etc., we just can't take it all into account. We think it's best to start with the basic suspension settings we described above and fine-tune the bike's suspension while you're riding. We want you to know as much as possible about your new bike and how its suspension works. And the best way to achieve this is to teach you how to tune the bike yourself.

Based on materials

Spring and spring rear suspensions first appeared in the 19th century. Bikes with rear suspension were periodically produced in the 20th century, but their heyday began only in the 90s at the height of the “Second Great Technological Revolution of the bicycle.” In the mid-90s, dual suspension bikes reached the masses.

Fundamentally, the rear suspension of a bicycle differs from the front only in that the rear wheel does not turn. It would seem that in this case it could be simpler - hang the rear wheel on one single lever and that’s it, nothing else is needed! That's what they did at first. But over time, significant shortcomings of the simplest suspension were revealed, and bicycle experts began to improve it. The points on which their attention was focused are as follows:

• The rear suspension of the bicycle is loaded much more than the front, which partly eliminates the issue of its sensitivity. However, another problem immediately arises: the loads applied to the suspension arms and rear shock absorber are quite significant, and require increased attention to their design. At the same time, the bicycle should remain as light as possible, that is, basic reinforcement with additional metal is contraindicated;
• The suspension must handle bumps effectively without swaying in time with the pedaling. And if the fork wobbles mainly when the biker sits up and pedals while standing, then the rear shock absorber is subject to wobble, even when the cyclist sits quietly in the saddle and pedals evenly;
• The design of the rear suspension should, if possible, eliminate lateral deformation, that is, have significant lateral (lateral) rigidity. At first this factor was not taken into account, but as dual-suspension systems became more widespread, competitive disciplines it became important.

Today, work to improve the rear suspension is being carried out simultaneously in three directions. Firstly, the kinematics of the suspension is improved, that is, the relative position of the levers and hinges. Secondly, shock absorber developers are actively using platform technologies in the rear suspension. And finally, bicycle engineers are tasked with creating both a technically and aesthetically sound design. The latter, as practice shows, is often very difficult - it is rare that technical rationalism goes hand in hand with the appearance of the bicycle.

Rice. Pendants
1 - main lever (swingarm), 2 - additional lever, 3 - connecting lever

The suspension system of the Specialized Epic bicycle is equipped with a Brain platform shock absorber, which contains a special inertia valve (in a separate reservoir). The valve reacts to impacts from the rear wheel. When the bike rides on a level surface, the inertia valve is closed and the suspension is “stiff”, which minimizes sway.

Rice. Specialized Epic Bike Suspension System
1 - Front triangle, 2 - Horst link (top stay), 3 - Main suspension arm (swingarm), 4 - Upper suspension arm, 5 - Main hinge, 6 - Horst link hinge, 7 - Hinge between the Horst link and the upper suspension arm , 8 - Upper suspension arm joint, 9 - Low point shock absorber mountings, 10 - Upper shock absorber mounting point, 11 - Brain shock absorber, 12 - Replaceable “cock”

Main types of pendants

If you look at the division of suspension types according to principle, then there are three main types:

• single lever, with Girvin swingarm. Represents the same simplest type suspension, when the rear wheel is mounted on one paired lever and swings around one hinge. Girvin's modern designs are simple, reliable, efficient and pleasing to the eye. A congenital defect of this type of suspension is rather weak lateral rigidity, at least in comparison with other types. Girvin's swingarm suspension is used by a huge number of companies, including such eminent ones as Cannondale and Santa Cruz;
• single-joint multi-link. A variation of the Girvin suspension, in which the main lever (swingarm) is lowered down, between the branches of the chain, and additional levers are added on top, transmitting force to the shock absorber and adding lateral rigidity to the suspension. It is important to understand that the trajectory of the wheel axle, as in the case of the Girvin suspension, is part of a regular circle centered on the main joint (usually located near the carriage);
• four-link, or multi-link. The difference from the above is that the path of the wheel is not part of a regular circle centered at a fixed point. This kind of suspension today is represented by two schemes: the classic 4-link with a Horst link and the newfangled suspension with a virtual axis of rotation (VPP-virtual pivot point). The first type is visually very similar to a single-joint multi-link with the difference that the hinge near the axis of the rear wheel is located not on the upper suspension arm (usually called the upper suspension arm, by analogy with the design of hard tails), but on the lower one. This design was developed by Horst Leiner and subsequently patented by Specialized. The advantages of this scheme are less dependence on the suspension during braking. The reaction forces that arise during braking do not “dull” the suspension as much as on single-joint designs.

The second variety has the general name VPP and is a further evolution of the 4-lever design. Here the bicycle frame is conventionally divided into two triangles - front and rear. They are connected to each other using two pairs of short levers. The carefully calibrated kinematics of this suspension allows you to simultaneously combat unwanted rocking and at the same time provide the suspension with very high sensitivity. And of course, the VPP suspension is also relieved from braking forces. A similar scheme is used by Santa Cruz, Intense and many others. Recently, the bicycle industry has seen a real boom in suspensions with a virtual axis of rotation.

Additional (non-traditional) types of suspensions

1. I-Drive suspension - single wishbone, with one main hinge. However, the carriage assembly is enclosed in the so-called. the Dogbone lever, which is located in a separate block. On the one hand, it is movable together with the main lever (swingarm), and on the other hand, it is kept from longitudinal movement by a flexible lever (Flexbone). In more recent versions, the flexible lever is replaced with a rigid one. As a result, the suspension combines the advantages of both a single-lever design (weak swing) and a multi-link design (weak kickback to the chain).

I-Drive has been around for quite some time. The first I-Drive scheme was a rather complex design with an eccentric carriage unit. In the new I-Drive, the bulky and heavy eccentric is replaced with the so-called. “god bone system” is a system of levers, the main one of which is one that looks like a dog bone. The main idea of ​​I-Drive is to avoid the influence of pedaling on the operation of the suspension, replacing the vertical movement of the carriage with horizontal movement. The specificity of I-Drive cross-country bikes is high reliability with relatively simple suspension, good performance, and really low sway.

Previous years' models had a distinctive feature: the shock absorber was shortened to 5.5" in length, which caused compatibility issues.

2. Scheme LRS - Low Ratio Suspension - suspension with low leverage. Used on Specialized Epic bikes. This is a variant of the 4-lever design with a Horst link. Moreover, a short I-Link is used, to which the rear shock absorber is attached - it is located almost parallel to the upper arm (stay) of the rear triangle. Advantages: compactness, classic geometry and high bending and torsional rigidity of the frame. the ability to use a long seatpost, the convenience of installing a water bottle on the frame. The suspension has a small shoulder, and the wheel travel is equal to the shock absorber rod travel (ratio 1:1), unlike other schemes that have a shoulder ratio of 2.5-3.5:1. This reduces the air pressure or spring precompression in the rear shock and improves suspension response.

This is one of the best, if not the best, rear suspension for XC and marathon racing. The main advantage is low leverage (the ratio of suspension travel to shock absorber rod travel is 1:1) and the presence of an inertia valve in the Brain shock absorber. The first gives the highest sensitivity of the shock absorber, and the second is simply the best implementation of platform damping I have ever ridden.

This frame has almost no disadvantages. Perhaps some people are a little confused by the rearward weight balance of the frame, this is due to the rear location of the shock absorber. But this drawback, by and large, is not such.

3. URT - United Rear Triangle - united rear triangle. The idea seemed quite original. The carriage is transferred to the rear triangle and, together with it, the chain and the system, rotates relative to the front triangle. Thus, the influence of the drive on the operation of the suspension is practically eliminated. There is another name for such a suspension - “scheme with a fixed long chain.” Indeed, in many other schemes, the rear triangle, turning relative to the hinge, tightens or loosens the chain, changing its length.

Rice. Softail BIANCHI CAMOSXC CARBON FS Travel 80 mm 1 - rear shock absorber DT Swiss XM 180 (31-37.5 mm), 2 - hinge unit to increase the lateral (side) rigidity of the frame, 3 - upper stays, 4 - flexible inserts of lower stays, 5 - tube for front derailleur

This is excluded in the URT scheme. Sometimes a URT suspension with a remote pivot axis was used, where the hinge was located on the down tube in front of the seat tube. This system made it possible to improve performance compared to a single-lever scheme, since when pedaling while standing, during a jerk or climbing a mountain, the lack of suspension mobility turns into a plus - energy is not wasted on swinging the suspension. But some shortcomings have emerged, and the main one is the almost complete “disabling” of the suspension when the biker rides while standing on the pedals. This is especially noticeable in structures with a remote axis of rotation. Surprisingly, in order to go over a root or ride onto a curb, you need to sit on the saddle! Therefore, schemes with a remote axis of rotation died out in the process of constructive evolution. But the classic URT scheme is used quite rarely now. Of the bikes with URT suspension that were popular in the past, the most famous are the Klein Mantra and Ibis Sweet Spot.

4. Softails. They are short-stroke double suspensions, in which, instead of the main lower hinge, lower stays (steel, titanium or carbon) or special inserts work for bending. The flexibility and elasticity of the rear stays allows you to reduce the size of the rear shock absorber. Suspensions of this type are used only in cross-country and have a travel of up to 100 mm.

The advantages of softails are:

• simplified design - one less hinge;
• slightly less weight.

The disadvantages, unfortunately, are a continuation of the advantages:

• complex, advanced technology for manufacturing chainstays;
• hence the high price;
• not suitable for extreme disciplines.

Some time ago, softails practically became extinct as a class, supplanted by lightweight short-travel dual-suspension bikes. However, the increasing use of carbon fiber reinforced plastic (CFRP) allows designers to return to the softtail design again. For example, the legendary Cannondale Scalpel, a short-travel cross-country dual suspension, remains a softail in both its first and second generations. There is a similar development from the companies Orbea (model OIZ), Sintesi (model 601) and BIANCHI (CAMOS XC CARBON).

Important from theory

In the front suspension of a bicycle (suspension fork), everything is very simple: the direction of movement of the wheel is rectilinear and coincides with the axis of the shock absorber located in one of the legs of the fork. In the rear suspension everything is much more complicated.

Firstly, the trajectory of the wheel is not linear, but closer to a circle. In VPP-type suspensions, the trajectory can be particularly elaborate, even S-shaped. Secondly, the longitudinal axis of the shock absorber most often not only does not correspond to the movement of the wheel, but is generally located at an arbitrary angle to the main suspension arms. Thirdly, the levers themselves, as well as their attachment points, cannot be positioned where you want - the suspension characteristics suffer from this.

All this leads to the fact that the rear suspension of a modern two-wheel drive is its most technically complex part. Designers are struggling to improve each of its characteristics, cutting out millimeters and adjusting degrees. Considering all the characteristics is a long and boring task, but it’s better to get to know the main ones.

• The trajectory of the wheel axle. For some reason, many people believe that this parameter is of paramount importance. This is not entirely true. The trajectory of movement affects the “softness” of handling uneven surfaces, as well as changes in the base of the bicycle - the distance between the axles of the front and rear wheels as the suspension compresses. In most cases, the trajectory of the wheel axle is the resulting characteristic obtained as an output after selecting other characteristics. However, almost all manufacturers try to make the trajectory such that at the initial moment of compression of the suspension, the rear wheel axis moves either vertically upward, or with some shift back, so that the handling of unevenness turns out to be the smoothest. However, you cannot get too carried away with this shift, since the next characteristic suffers from this.
• "Chain Snatch" Occurs due to an increase in the distance between the points of contact of the chain to the driving and driven stars. At a very large value, when the suspension is compressed, the virtual lengthening of the chain causes it to jerk back, which is expressed in turning the pedals against the direction of the bicycle. The intensity of the jerk depends on the suspension design and the currently selected gear (especially important for front sprockets).
• location of the instantaneous center of rotation of the rear suspension. How the bike will behave when pedaling directly depends on this factor. A properly selected instantaneous center of rotation will allow you to “decouple” the bicycle from the action of the suspension, that is, minimize the influence of pedaling on the operation of the suspension. In 4-link designs, the instantaneous center of rotation changes its location as the suspension compresses. On the one hand, this adds headaches to the developers, and on the other hand, it allows optimizing its placement in the most delicate zone of small suspension strokes, which is critical to sway when pedaling.
• Compression characteristics. It represents the dependence of the force acting on the wheel axle and/or shock absorber rod depending on the current value of the suspension travel. This is one of the main characteristics that determines the behavior of the suspension. By changing the graph of the compression characteristic, you can give the suspension linear or, conversely, progressive operation, and also set the operating modes of the suspension at its different strokes. In addition, this characteristic is related to the type of shock absorber. A coil shock absorber with a fully linear self-response requires one compression characteristic of the suspension, while an air shock absorber with a progressive intrinsic characteristic requires another.

All other kinematics characteristics are of secondary importance.

A key concept when tuning a mountain bike's suspension is shock absorber (suspension) sag. Static sag is usually measured as the difference between the length of the shock absorber without a rider and the length of the shock absorber with a rider on the bike.

Moreover, it is best to take exactly the position that you usually take on a bicycle. If you are focused on descending, it is better to stand on the pedals and place the “fifth point” (center of gravity) where it is usually located. Leaning on your foot or removing your hand from the steering wheel is strictly prohibited! The weight distribution along the axles will change. You can't do this without outside help.

An assistant will not need a long tape measure, a ruler is enough, just explain to the beginner what to measure... Let him measure the length of the inner pipe (axis) between the fixed boots and stops. I do not recommend measuring subsidence using a plastic clamp or rubber ring on the “leg”. When you sit on a bicycle, you push the “mark” much further than in a static position. This method will help you see whether you are using the entire stroke of the shock absorber, but this is only after...

With a cross-country riding style (for vigorous pedaling), the sag should be within 10-20% of the maximum suspension travel. Naturally, the settings are made tougher for racing. For downhill disciplines, subsidence is set within 20-30% or even more. Some extreme sports enthusiasts “hide” half the travel, so the wheel seems to stick to the uneven surfaces.

How is subsidence established?

On air shock absorbers, they simply pump air into the main chamber if it sags too much. Reduce pressure if there is insufficient subsidence. Don’t forget to look at the manual at least out of the corner of your eye; there’s probably a sign there that indicates the recommended pressure for your weight and riding style. The main thing is that it says the maximum pressure for which the insides of the expensive device are designed. You know, it’s better not to exceed it.

With spring-oil shock absorbers it is a little more complicated: initially they are equipped with springs designed for the “average” cyclist. Therefore, light riders or, on the contrary, heavy ones or those who like to land hard are most likely to “buy” the spring.

For a suspension fork you will need two of them; most often the settings in both legs are made the same. But the principle remains the same: the legs sank greatly -
Tighten the spring to make it stiffer. It sags very little -
unscrew, loosen. On the fork, the adjustment knobs are located at the top and have limiters. If you don't twist them with pliers or a big wrench, you won't break anything.

But with the rear shock absorber it is a little more complicated. There are no limiters, so there is a risk of breaking the spring or thrust nuts. The main thing to remember: NOT ONE rear shock absorber spring should be compressed (from a free state) by more than 10-15 mm! The spring stiffness is set once and for all during manufacturing. By squeezing it tightly, you will load the stops, the shock absorber rod (which will certainly lead to breakage) and weaken the spring.

One of the well-known manufacturers of racing shock absorbers writes in the instructions: if you need to tighten the spring more than two turns, you need a slightly stiffer one. It is quite clear that the spring should not dangle, the thrust ring serves as a stop, otherwise, if it gets skewed on the shock absorber rod, it will break itself and disfigure everything around it. And if this happens on the descent...

Further. Your shock absorbers probably (only the cheapest ones don’t have more settings, look at the manual for your shock absorber) have a rebound adjustment knob. There is nothing complicated here either; first you need to completely “unscrew” the handles, for example, the forks. Make the rebound the fastest. Don't forget about symmetry in the settings. Unscrew the right handle, unscrew the left one too. Then, adding half a turn (everything is symmetrical: half a turn to the left, half a turn -
on the right), vigorously push the steering wheel down, squeezing the fork. The steering wheel should bounce as quickly as possible, but there should be no push (“kickback”) to the hands.

The rebound of the rear shock absorber is adjusted in exactly the same way, only you compress the suspension with your feet while moving. There should be no kickback or bouncing, otherwise the wheel will slide only on the tops of bumps off-road. It is quite possible that you will turn the rebound adjustment knob halfway, maybe further. Whoever likes it. Lag, rebound too slow -
bad too. During a series of impacts at high speed, the suspension “will not have time” to straighten and with each impact it will become more and more rigid.

Now it's time to test.

First test- you place a board, a thick stick on the asphalt, or find a bump on the path. You don’t accelerate too much and, standing on the pedals (this is how bumps are usually passed), you pass. With your feet and hands, feel the center of gravity to see if there is a sharp upward push from the suspension?! There should be no springy upward rebound. The blow should be smooth and soft.

Second test- jumping off the curb at speed. There should be no rebound of the suspension in this case either. Moreover, the swinging (creak-creak-creak) of the suspension. Bike -
not a spring bed. With such simple tests, in addition to all of the above, the balance of the front and rear suspension is checked.

For long trips and racing, the stiffness, rebound and compression of the front fork and rear shock should be identical, there should be no rocking forward or backward. If you are planning to drive only downhill, it is useful to adjust the rear shock absorber a little softer, with a slightly slower rebound, because in such cases the rear wheel is less loaded. On a flat surface, then, a feeling of a “soft tail” appears. Likewise, the sag of the rear suspension may be a little more, there is nothing wrong with that, a couple of years ago the travel of the rear suspension was 20-30% more than the front.

If you're lucky and your bike has expensive modern systems damping, which means you can experiment with adjusting the compression. This setting changes the shock absorber's compression resistance.

Here it all depends only on your riding style, riding location and preferences. With this adjustment, you can set a kind of “pedaling platform” (reduce suspension sway during vigorous driving) or reduce the likelihood of breakdown (hard compression of the suspension to the limit). With strong compression resistance, the suspension handles large bumps and rocks better and works well on hard landings. On small irregularities, it will not have time to operate. Grip will be poor and braking will be choppy. With low compression resistance, the shock absorber will “work” perfectly over small roots and stones, but a strong impact will
will miss. This is creative freedom!

Finally: Don't think you've made the final adjustments today. If your driving style, routes, mood changes, or you stop driving from the mountains, then you will want to turn the tuning knobs. Try to write down the settings, it will be easier to navigate, because some shock absorbers can be adjusted according to five or six different parameters!

Most professional racers change the pressure, springs and recalculate the clicks of the tuning knobs after each training ride. Some people tune the bike only for a specific route. And some people tune the bike only once.

The fork is the second most important part after the frame, both in price, cost, and weight. The quality of the fork determines how comfortable the ride will be. Not only shock-absorbing properties are important, but also flexibility of settings, matching the type and class to the riding style. For example, a rigid spring fork is great for riding in the city, but a short trip into the forest can be fatal for both the mechanics and the cyclist.

Types of suspension forks

Spring

Basic level of suspension forks. They are installed on cheap bicycle models and are sold at retail on a residual basis. They are usually used as spare parts for repairs. Due to their design, they do not act as a damper, allowing minor irregularities to pass through in full.

This fork is based on a regular spring, closed in the connecting rod under rubber or other protection. Usually it is assembled quite roughly and during use it deteriorates from the ingress of dirt. Maintenance options are limited - usually only replacing the spring itself. There are no settings either, only locks.

Spring-elastomer

The mechanics are no different from the previous ones, but instead of a spring, a polymer rod is used, which acts as a damper. Unfortunately, it all depends on the properties of the material, but usually they are far from perfect. The shock-absorbing function is slightly replaced by the damping function, maintaining the overall low comfort from using the fork.

Spring and elastomer front forks are not recommended for winter use as the degradation at low temperatures is too severe.

Air

The all-air-cushioned design is very advantageous both in terms of cost and maintenance. Compressed air pumped into a sealed chamber works both as a shock absorber and as a very good damper. The ride is very comfortable, comparable to many more expensive designs, but if you buy a mountain bike, you should choose a more durable mechanism.

The disadvantage of air ones is preparation and service life. The adjustment is made only by the pressure in the chamber, since it is quite narrow, it is necessary to pump up very often, and the overall service life of such a mechanism, especially when aggressive skating, small.

Oil-air

Oil-air forks split the shock and damper functions between the air chamber and the oil cartridge. If the behavior of the air “spring” is understandable and similar to the air fork, then a lot depends on the oil block. The main choice is based on the structure of the cartridge and the brand of oil.

This type of design is great for cross-country and constant riding, but fails under heavy loads on mountain slopes. In addition, the service life is expected to be lower than that of spring mechanisms.

Oil-spring

The recognized professional type of front fork is a device combining an oil cartridge and a steel spring. These are the forks that stand on the best sports bikes, but, depending on the cost, oil-spring structures are replaced with oil-air ones.

Typically, the possibilities for adjustment are lower than with air springs, but a spring, especially one made of modern materials, allows you to work for a very long time and with the required stiffness.

Both oil and shock springs have passed huge way improvement and together give the best sports combination. At the moment, the bicycle industry cannot offer any possible competitors for this combination.

Basic parts of a bicycle fork

Conventionally, the front fork can be divided into four component blocks:

• shock absorber - a part that takes on the main load of absorbing unevenness and the movement of the bicycle, in some models it is a spring, in others it is a sealed chamber;
• damper - shock absorption of small irregularities that must be worked out quickly;
• the body is what bears the main load: the head tube, the inner tubes (rods), the crown connecting the head tube and the inner tubes, the legs (the lower shock-absorbing block that includes the connecting rods), the gorilla (the bridge that connects the legs);
• accessories - switches and settings on the crown, legs, a set of fastenings for the wheel axle and brakes, boots and cuffs to protect the mechanisms.

Bicycle fork parts

Settings

The set of settings depends on the type and manufacturer. Let's consider all the possibilities. A single type of switch has not yet been developed, so each front fork will have to be configured according to the manufacturer’s instructions.

LockOut – move blocking

There is a lock on almost any fork. This switch is most often used not during preparation, but during the riding process, for example, before a hill or a high-speed section on the asphalt. You should not abuse this function. Having significantly saved energy, it is easy to get a serious blow to your hands on the slightest bump and break the switch. In addition, such a move does not bode well for a bicycle either.

Preload is usually adjusted by an external switch, but can be (on the cheapest and most expensive models) simply by replacing the springs. It affects depreciation, and specifically the actual stiffness of the spring, by tightening it. In sports kits, when adjusting by replacing the spring, different levels of stiffness are marked in color.

Compression & Rebound – speed of compression and return

The setting is found in good level forks. Responsible for the return speed and compression resistance is the switch, usually on both sides - on the legs. Most often, it is the return that is regulated - for jumping and downhill, slow down so that it doesn’t fly out faster, for skating faster, so that the grip is not lost and the pedaling energy does not go into frame distortion.

Extension control – stroke length

Expanded blocking option - several positions are added that fix care along a certain length. For example, at 100 mm with a maximum travel of 150 mm for straight sections instead of jumps. The risks of using such switches are similar to blocking. Under active load, the switch can be broken. In any case, the need for customization is quite low, so it is found only on a few models.

How much fork travel do I need?

The best choice is 100 mm. The gold standard for almost everything.

Fluctuations within +/- 20 mm of travel are permissible. If you ride something else, then you already understand why you need a fork with a long travel. There is also 80 mm, but this is about budget and teenage models. And you remember that budget sure bets don’t work.

Rigid forks

Rigid (from the English rigid - hard) is a type of bicycle that does not have either a front or rear shock absorber. This is the oldest classic bicycle design, which was widespread until the global MTB revolution that began in the late 70s.

Two different rigid forks

Consequently, the fork on such a bike is rigid. They are made in a variety of shapes and a variety of materials. The most common: aluminum, steel and carbon.

Pros of a rigid fork:

Cons of a rigid fork:

• It is difficult to control on severe off-road conditions, especially for beginners;
• In the case of a rigid fork, it is necessary to absorb unevenness with your hands, which requires some habit and correct landing. If the elbows are fully straightened, it will become difficult to soften the blows. The video is designed to destroy the stereotypes of the indispensability of MTB bicycles on off-road. Discipline - cyclocross;
• Carbon rigid forks are afraid of strong side impacts and chips.

What types of rigid forks are there?

Aluminum

The most common and available material today, it is used for the manufacture of frames and forks of most modern bicycles entry-level and mid-price category. Aluminum forks are light, stiff and are the best at absorbing vibrations and shock, so try to avoid an aluminum fork!

Steel

Steel is much more ductile than aluminum, so it dampens vibration much better. The disadvantages include the highest weight and increased susceptibility to corrosion. It is better to stay away from heavy steel frames and forks of cheap Auchan bikes, but lightweight Cr-Mo steel forks (cromol) and frames are a generally accepted standard among cyclists: good vibration damping, guaranteed reliability and reasonable weight for a reasonable price.

Titanium

One of the most expensive materials along with carbon, the lightest among metal analogues, perfectly dampens vibrations, is not afraid of corrosion and is very durable. Does not require painting, looks great. Titanium forks, frames and racks are highly valued among cyclists for their greatest reliability and lightness. There is one downside: high price and low distribution. Titanium structures are often made to order.

Carbon

New generation material: the lightest, perfectly absorbs vibrations. Used in professional bicycles, ranging from road bikes to downhill bikes. It is reliable under the “correct” loads, but is fragile to impacts from stones, falls, and is afraid of chipping. All nuts and clamps must be tightened extremely carefully so as not to break the fastening point.

However, technologies for the production of carbon parts are constantly being improved; many cycling enthusiasts have appreciated carbon parts. Great importance the manufacturer of this carbon fiber has - in the video you can watch a video about the strength of a branded carbon frame, while no one promises you the quality of Chinese carbon.

Bicycle rear suspension

The rear suspension of a bicycle is a system of a spring (leaf spring) and an element that damps vibrations - a damper. A spring is a metal spring, or, if the bike’s light weight is important, an air cartridge.

This is what a bike's rear shock absorber looks like

Metal springs are used in cases where a quick response of the structure is required when moving at high speed, because... they have the ability to instantly compress and straighten. An oil or air cartridge is used as dampers. Based on the type of cartridge, rear suspensions are divided into air-oil and spring-oil.

The oil cartridge slows down the shock absorber's response to loads. The quality of damping is the main characteristic by which high-quality bicycles differ from cheaper ones. Expensive models may have a system for adjusting the shock absorber response speed.

Rear suspension types

There are three types of rear suspensions:

1. Cantilever suspension is the very first type of shock-absorbing system to appear. It is a structure of a pendulum attached to the frame by one axis and directly connected to the shock absorber. This system is easy to manufacture and has good functionality. However, it has a small stroke compared to the others (about 200 mm).
2. Multi-link suspensions differ in the way the pendulum is connected to the shock absorber. For this purpose, there is a system of levers on hinges, which each individual manufacturer may have its own. Such designs are more difficult to manufacture, they increase the cost of the entire bike and quickly become loose - but they provide much greater suspension travel than cantilever ones.
3. The “triangle” type differs from the previous two in the location of the transmission, which is entirely attached to the rear pendulum, and due to this remains elastic when moving. This type is very common nowadays.

Suspension travel

The amount of travel the rear suspension of a bicycle has determines how “soft” it will be when moving, and also how difficult it will be to accelerate it on climbs and during normal horizontal movement. In cross-country bikes it is less than 130 mm - which makes impacts from bumps sensitive, but allows you to easily climb hills.

Models designed for extreme riding, high-speed descents and big jumps have a stroke of more than 150 mm. This design removes excess stress from the joints and spine - but makes it difficult to drive on a flat road.

On average, if you want to combine regular cross-country trips and not very steep descents and uphills, it is better to choose a suspension with a travel of 130 to 150 mm.

How to choose a bicycle fork and what to look for

Price: We have already explained why good forks are expensive. If you have ridden a bike and have already killed your elastomer, but you want to ride a lot, and you like it, buy a good fork. In terms of price, it will be the same as buying a bad one 2-3 times, and the service life of good forks is proper care much longer.

We have already talked about comfort and a different world of riding possibilities. If you just ride around the park and you are happy with everything, you don’t want to grow, fix the elastomer. If you already have a good fork, but want an even better one - and you don’t know where else to spend money - you can invest in an upgrade, but at the same time you must clearly understand what it gives you, and why you need to lighten the bike for these 200 gram for N dollars.

Common bicycle fork sizes

If you intend to race, a good and expensive fork will help you win something

Riding style: There are two options here: for riding and for more aggressive riding with jumps. In the mountains you need a good fork, on the dirt you need a good fork, and when jumping, good shock absorption is irreplaceable. And technology. If you don’t know how to ride technically, the fork doesn’t solve the problem. But if it’s not there, it’s very difficult to drive technically. Therefore, when choosing a fork, you already understand where and how you want to ride. If you don’t understand yet, take a good entry-level fork, if something happens, sell it and buy what you need.

Rider weight: If you weigh within the average statistical norm, there will be no special problems. If you are light and fragile, air piston forks give you the opportunity to adjust the weight to suit you.

If your 100 kg are moving briskly at high speed down the rocks, don’t buy lightweight forks with thin legs. You need to choose models that have large stock mechanical strength.

Typically, forks are rated for a maximum weight of 110kg, so be sure to check these parameters before purchasing. You need to take thick legs, control the stiffness, inflate correctly, the main thing is that it does not break through (the situation when the fork is pressed in completely and at the end you can hear the characteristic sound of the legs hitting the stationary parts, the situation is fraught with the fact that you can damage the insides of the fork, and repair it is difficult and expensive, and not always possible).

Popularity and ease of maintenance: a strange criterion, but so far, in our conditions, expensive forks are rarely brought to us, and there are not so many specialists who could repair them. Therefore, try to choose popular models, this way you guarantee yourself that if something happens, you will find a master who has seen such a fork and knows how, and spare parts for it can be bought in our country.