The hydraulic drive is a pump that pumps fluid and transmits torque from the carriage to the wheel. The fluid flow generated by the pressure of the pump piston is converted into mechanical energy.
The drive works silently and can be used as a hydraulic brake. This mechanism requires minimal maintenance. Torque is transmitted in both directions (forward, backward), so the drive can be installed on the front, rear or both wheels,
- Low efficiency, about 70%,
- Heavy mechanism weight,
- If the hydraulic actuator breaks, then the entire system will fail.
Track models are designed exclusively for high speed cycling. The design is simplified to the limit, the weight of the bike is lightened. No brakes, fixed transmission, one gear ratio, narrow aerodynamic wheels with hard rubber. everything is done to increase driving speed.
There are many riding styles, some of them, the most popular, are described below.
Cross country. This riding style involves racing over fields, forests, slopes and short climbs. Cross-country is preferred by most cyclists, with this style of riding injuries are minimal.
Wheel diameter should be between 26 and 29 inches. Or else, two-suspension, short-travel light bikes will do.
Freeride. This riding style is subdivided into several more subgroups: North Shore, Dropping, Classic and others. Classic involves overcoming difficult sections of the track (from natural and unnatural surfaces), with jumps, steep descents, and movement along narrow paths.
North Shore involves riding on special structures, logs, narrow scaffolding and swings. And serious jumping from a great height on bicycles is dropping. The strength of the bike is important here, so it has a lot of weight. From this driving style, users get a lot of impressions and a sea of emotions, not always such a hobby just for the sake of a better result.
Downhill. It involves a descent at high speed on natural or artificial turf. It can be stones, special trampolines, tree roots sticking out of the ground. A downhill bike looks very similar to a freeride bike. It has a powerful braking system, a solid frame, a short stem, a wide handlebar, large tires, a suspension of about 2 cm.
The only difference is in some geometry of the frame, the angle of inclination of the cooler column is reduced, and the center of gravity is lowered, which allows not to overturn forward when leaving the mountain. Downhill bikes weigh about 11 kg, but professionals can easily cope with such difficult machines.
Enduro, All Mountain and Trail. They represent a cross between freeride and cross-country, sharp descents, high climbs and virtuoso jumps. These three styles are similar to each other, but there are some differences.
Enduro involves endurance and time trial racing, a style of riding that comes from motorcycling. All Mountain and Trail is more about fun, rivalry is irrelevant.
The rear shock and fork must be locked so that the suspension does not sway on descents. Telescopic seat posts are used to raise the seat on the slopes.
For biker cross, a hard trail with wide tires, a long frame and a light fork with 1 cm travel is great.Also use two-suspension mid-travel or short-travel bicycles.
Dirt jumping or dirt is jumping on trampolines from the ground, sometimes with performing additional tricks in the form of flips and steering. Jump represents departure and landing.
Dirt jumping bikes are used with 26 ” wheels, single speed and 1 cm travel forks.
The brakes are usually removed from the bikes so tricks can be done easily.
Straight. This style is suitable for city travel. Driving on asphalt, obstacles only in the form of stairs, curbs and fences. Externally, the bike is similar to a turtle bike, but it has a shorter frame, which allows it to balance perfectly on the rear wheel when surfing. Forks are most often used chrome-molybdenum, for greater rigidity. Wheels fit 24 and 26 inches.
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Trial. Driving style with overcoming various obstacles such as logs, boards, stones, parapets. It is important to be able to balance not only on two wheels, but also on one. The trial unit does not have a seat, it also has a rigid fork and a light frame.
Only one speed is needed, but powerful brakes are needed. Long stem with forward center of gravity for easy rear wheel balance.
A hybrid two-wheeler is a combination of a road bike and a mountain bike. You can also drive it on the highway at high speed and drive into uneven terrain. Wheels have a large diameter of 28 inches, treads are medium, the frame is high, there is a suspension fork and disc brakes.
Stunt bikes are characterized by small wheels, in the order of 20 inches. BMX models are equipped with a mechanism that allows you to turn and twist the steering wheel in one direction without harming the brake cables.
Instead of a chain, a shaft is used to transmit torque. This type of drive is usually called cardan, although the cardan itself is not here, a straight shaft with a transmission does all the work.
The shaft drive is easy to operate and will last a long time, because the whole mechanism is protected from dirt and dust. But for gear shifting, additional planetary bushings are needed.
The walking bike is an urban type and is an improved road bike. This type has usually an open frame, a seatpost or front shock absorber, a wide padded seat, fenders, a rack or basket, and chain protection. Multi-speed (7-12 speeds), with cassette gear shifting mechanism.
It is not designed for high loads, that is, it is not suitable for jumping and overcoming difficult obstacles. Designed for walks in squares and parks of the city, suitable for older people leading an active lifestyle.
Side wheels included
Some models of children’s bicycles come with two side wheels. Toddlers, just getting used to the new transport, cannot always keep their balance, therefore, additional wheels are extremely necessary for the child to be able to balance normally and ride calmly without tipping over on its side. When the movements become more confident, the wheels are removed.
The side wheels are a safety net and guarantee. Sizes can be different from 12 to 20 inches, when choosing, you must focus on the age of the child.
Bicycles with a low frame are considered to be women’s bicycles, since they can be ridden even in a skirt. In addition, the women’s models have a high seating position, wide rims and tires, an increased wheelbase, a wide and comfortable saddle.
Due to the differences in the physical anatomy of the sexes, the distance from the saddle to the handlebars is less for the transport for women. The frame is made of aluminum for the lightness of the bike. The design of the pedals is comfortable and allows you to move around in any shoe, even with a small heel. The handlebars are a few centimeters narrower than the men’s models, and the brake lever matches the anatomy of a woman’s palm.
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Before buying, pay attention to the weight of the bike. For models for girls, it is 9-13 kg. Heavy bicycles are difficult to lift and carry. An important factor when choosing is the presence of additional elements (baskets, shields, trunk). they add weight to the whole structure, but add functionality.
How to choose
Threaded. Considered an outdated type of column, but used in the construction of inexpensive bicycles. Often fitted on road and sport bikes. They are quite simple and easy to adjust.
An example of an Altair bicycle with a threaded column.
Threadless. modern design.
The photo above is an example of a Mercedes bicycle with a threadless column, but there are three varieties of them:
The last type is quite tough. Suitable for mountain bikes and hybrids. Slightly adjustable in height.
Another particular variation on the theme of semi-integrated steering columns. The system consists of cups pressed into the head tube and separate industrial bearings.
The main difference from the semi-integrated Zero Stack is the special bearing size and, of course, precision execution. The outer diameter of the Perdido cup is 44.5mm and the required head tube diameter is 44.4mm. As we said earlier, the diameter of the ZeroStack cup is only 44mm, so Perdido is declared as an independent standard, although in principle there is nothing new in it.
In some cases it is possible to re-drill the ZeroStack aluminum frame to the standard 44.4mm Perdido diameter. It follows from Honor that Perdido cups are more recessed into the frame, therefore it will be necessary to increase the depth of the seat.
Threaded steering column
A threaded steering column is still one of the most common standards for attaching a fork to the frame. Although this circuit is now largely abandoned on professional road and MTB bikes, due to its unpretentiousness it can still often be found on entry-level touring, road and ATB bikes. The word “threaded” comes from the presence of an internal thread on the upper cup and lock nut, due to which the fork actually holds.
The bearing cups are pressed into the steering tube, where the bearing balls hold separate rings with rolling grooves at the top and bottom of the bearing. The final strength of the structure is given by the fork, which is attracted to the bearings by means of a locknut. At what moment you set the stem, it does not matter anymore.
There are several versions of this mount, sharpened for different diameters of the fork stem. The most common are: 1 “, 1-1 / 8” and 1-¼ “.
Integrated systems without cups
Numerous variants and sub-variants of this standard have in common the absence of external headset cups, when the bearings are pressed directly into the head tube, which, of course, requires a compatible frame. Only industrial bearings are used here, since the balls will gradually grind off the rolling groove, and the frame will no longer be suitable for further use.
The most common bearing size has a 41mm outer diameter and a 45 ° bevel (correspondingly, this is the angle inside the frame). There are variations of this standard using a 36 ° bearing and frame bevel.
The rest of the fork installation process is similar to the Aheadset standard. it is held in place by the steering column anchor. In general, the name “integrated steering” does not belong to the generally accepted standard. It is applied to the headset class where the bearing is pressed directly into the frame and is typically 41mm in diameter. Sometimes this gives certain difficulties with the search, in the case of replacing bearings on exotic frames.
Semi-integrated (Zero Stack or “Low Profile”)
A standard that is equally likely to be found on both carbon and modern aluminum bikes. The main difference from the threaded and Aheadset standards is the cups and bearing, which now fit directly into the head tube. Outside, we will only see a ring with a rolling groove or a boot.
On budget models, needle bearings or cage bearings are often used. In such cases, the cups not only support but also act as an outer ring with a rolling groove. In expensive models with an industrial bearing, the cup only holds the housing. The most common crimp diameter is 44mm, but other specifications such as height and bearing used may vary by manufacturer and model. The main advantage of this standard is the zero height relative to the head tube, which allows the handlebars to be lowered as low as possible.
“Steering” bike, device
To understand the structure of a bicycle steering column, you need to start by understanding the steering mechanism of a bicycle, in principle. And the steering mechanism is a whole complex of parts that allows you to direct the movement of the vehicle in the direction the cyclist needs.
- handlebar (crossbar or some more complex design) with grip points and fixed accessories, grips;
- stem (pipe) with handlebar and steering tube mountings;
- a steering tube that connects the stem or handlebars to the crown of the fork and goes into the glass and the steering column;
- steering column, consisting of two cups, bearings (upper and lower), rings (optional) and allowing the tube to rotate freely in the glass;
- head tube or part of the frame with chamfers cut to a certain standard inside, where the bearings of the column and its cups are inserted.
The steering column of the bicycle ensures the rotation of the fork in the tube of the frame. Currently, there are two types of speakers (divided by the method of attachment to the plug):
The figure on the right shows a disassembled threaded column.
The modern bicycle steering column provides flawless control of your two-wheeled friend while on the move. This is a special system of cups, bearings and thrust washers. Their quality and reliability. safe and comfortable riding on road, city, children’s and mountain bikes.