How to choose the right bike cassette
- Bike cassette - purpose, principle of operation, a variety of models
- Bike cassettes differ in a number of criteria:
- There are 5 types of cassettes by design.
- How to choose a cassette for your bike
- How to maintain a cassette
- Where can one buy?
The cassette belongs to small, but extremely important nodes of a bicycle. It in combination with other elements of the transmission allows for a slight change in muscular effort to provide a fairly wide range of speeds for racing and driving on rough terrain, ups and downs.
Cassettes consisting of a certain number of stars of different diameters with a larger or smaller number of teeth on them are suitable for different types of bicycles and riding style.
In addition to the frame and wheels that form the basis of the bicycle’s construction, it consists of a number of small, but equally important components, controls and a chain drive that converts the cyclone’s muscular energy spent on pedaling to the rear wheel axle torque.
So that it was possible to develop a significant speed with less expenditure of muscular energy, the chain transmission is equipped with a gear-shifting mechanism consisting of two groups of stars of different diameters and switches. The chain passes through the front and rear stars. The front stars are combined into a system to which the connecting rods and pedals are attached, and the rear stars - in a cassette.
Bike cassette - purpose, principle of operation, a variety of models
Bicycle cassette is a node consisting of a set of rear stars of the transmission and dividers between them (in some designs). The cassette is fixed on the rear hub of the wheel. For its installation, a spline fit is used, for fixing - a locking nut (retaining ring).
The stars (all or individual, depending on the design) are attached to the fastening element having grooves, and there are protrusions on the sleeve body of the corresponding configuration, which ensures the correct installation of the cassette. In modern models of bicycles cassette performs the same function as in the old or cheap bikes - ratchet. The cassette is a more complex, high-quality and functional site.
The cassette is involved in the transfer of force applied by the cyclist to the rotation of the pedals from the chain to the rear hub, while changing the gear ratio of the transmission. This is the knot on which the speed of the bike depends. The number of stars in the cassette corresponds to the number of speeds (gears). The cassette may consist of different numbers of stars, from 7 to 11, the stars, in turn, differ in diameter and number of teeth.
With the help of the rear switch of speeds the chain is transferred to different stars of the cassette. This changes the gear ratio, that is, the ratio between the number of teeth of the front (leading) star, which is part of the system, and the rear (slave), which is part of the cassette.
The greater the gear ratio, the higher the speed can be developed, but it also takes more effort. A downshift gear when there are fewer teeth on the driving star than on the driven one, is used for heavy sections with loose soil or steep climbs, usually for a short time. Throwing the chain on different stars, you can choose the optimal speed for each segment of the route.
Bike cassettes differ in a number of criteria:
- by the number of stars and their range
- compatibility with hub system and bike type
- by design
- by material
The number and range of stars are reflected in the labeling of the cassette. So, marking 11-36Т 10-speed means that the cassette consists of 10 stars, the smallest has 11 teeth, the largest - 36.
The number of stars in a cassette can vary from 7 to 11, but today cassettes with 8-10 stars are most common, seven-speed cassettes are used in older models, and for 11 stars they are produced only by Campagnolo and are compatible only with bushings of this system. The number and range of stars depends on the type of bike on which the cassette can be mounted.
For road bikes, cassettes with the number of teeth on a smaller star are 11, on a larger 22-27. For mountain the smaller star in the cassette should have 11-12 teeth, the largest - 28-36. Cassettes with markings 12-27T are considered transitive. The 11-star cassettes are used only on Campagnolo road bikes. The labeling usually also indicates which attachment system this cassette is compatible with.
There are 5 types of cassettes by design.
- Collapsible. The stars are interconnected by rivets or screws, which allows replacing individual stars in case of wear. This is the most affordable design, its drawbacks are high weight and susceptibility to contamination.
- On the spider. From 2 to 6 stars, inextricably interconnected by an alloy spider. Low weight and less polluted
- On several spiders. Each spider combines 2-3 stars, these nodes are combined into a cassette, individual nodes can be replaced
- OpenGlide. The monolithic conical design with teeth, the smallest star is the smaller base of the truncated cone, on this side the cassette is closed with an aluminum cap. In the cover there is a hole designed to contact the cassette with the hub drum, the second point of contact in the small star. These cassettes are designed exclusively for road bikes.
- X-Dome. Like the previous design, developed by SRAM, it is distinguished by its low weight due to the combination of different materials. The biggest star is made of aluminum, has its slots for installation on the drum, there are still slots in the smallest star. The middle stars are combined into a monolithic structure, machined from a single steel bar with chromium and molybdenum additives; this block is fixed between the large and small stars, by means of which contact with the free wheel is made
X-Dome cassettes use both steel and aluminum, but for most cassettes, one of these metals is used. In addition, cassettes can be made of titanium alloy.
- Steel cassettes are distinguished by an optimal ratio of strength characteristics and cost, to protect against corrosion, steel is chrome-plated, nickel-plated or coated with another composition. Steel grade and additives affect the strength and durability of the cassettes, as well as their price.
- Aluminum cassettes have the least weight, but they are inferior in strength and resource to steel ones and exceed them in price. Anodized aluminum alloy cassettes are popular with weitwinners, who strive to lighten the weight of the construction as much as possible.
- Titanium alloy is lighter than steel, but heavier than aluminum alloy, it has considerable strength and wear resistance, but the most expensive cassettes
How to choose a cassette for your bike
The bike is sold with a cassette, but periodically there is a need to replace this node. This is due to the wear of the stars, which have erased teeth, slipping the chain can signal that it is time to change the cassette. But sometimes replacing the cassette is dictated by the fact that the cyclist goes to another region with a different terrain and type of soil, plans to master a different style of riding.
In the first case, you can safely choose a cassette with a label similar to the old one, with the same number of speeds and a range of stars, and if you want to experiment, test products from another manufacturer, another material. In the second case, a change in the number and range of stars is justified.
The first thing you should pay attention to is the type of bike, mountain or road, and the attachment system. Which cassettes to which bike fit, described above. You must also consider your financial capabilities, but remember that expensive tapes are stronger and more durable. If the priority is not to minimize the weight of the bike, do not spend money on titanium and aluminum cassettes, it is better to buy a more expensive one among the steel ones. Here the price is directly proportional to the resource.
From a constructive point of view, it is worth paying attention to the cassettes on several spiders, they are easier than usual collapsible, less prone to contamination and allow you to change individual nodes, rather than the entire cassette. Thus, although such a cassette will cost more, it should last longer.
The more styles a person uses, the more complex the relief on the route that he passes, the more stars in the cassette it is more expedient to have. A larger number of stars means a larger range, smoother gear shifting. For a flat terrain, a smaller number of stars is enough; for broken terrain, they need more. The number of stars should correspond to the chain, narrow chains are intended for cassettes with a large number of stars, 9-11, if the chain is wide, there should be fewer stars.
The cassette for 11 stars allows you to practically not use the front speed selector. The optimal number of stars is a very individual criterion, and often only by experience, having changed several cassettes, it is possible to establish which configuration provides the most comfortable ride. Experienced cyclists generally collect cassettes from individual stars for their needs and for a particular trip.
The required range of stars depends on the style of riding. If you plan to drive on a good, solid ground, asphalt, without height differences, steep climbs, the number of teeth on a small star is not important, but on a large enough small number, a range of 11-21, if on a route small slides can occasionally occur, 11 -23. If you are going to ride on loose, wet ground, sand, snow, and / or alternating steep, but short lifts (“butts”) with more gentle, but prolonged (“traders”), you need more teeth on a big star, a range of 12 will do. -36. The steeper the mountains, the greater the range needed. And yet, the more massive the cyclist, the more teeth on a big star will be needed, all other things being equal.
In short, when choosing a cassette you should be guided by your own experience, feelings, riding style and purpose of the trip. If the experience is not enough, it is better to consult with other cyclists, sales consultants do not always know all the nuances.
How to maintain a cassette
Like any bike knot, the cassette needs maintenance. Cleaning from pollution, replacement of worn out parts will make cycling more comfortable and safe, as well as extend the life of the node and the chain to which pollution is transferred. Especially important maintenance collapsible cassette.
To service the cassette it must be removed. To do this, you need a special puller that matches the type of sleeve, a key, preferably adjustable or under the size of the puller, and the so-called whip from the handle and piece of a bicycle chain, you can make it yourself.
May also need a means of sticking to the parts and lubrication.
- Removal of the cassette is preceded by removal of the rear wheel and careful removal of the eccentric axis
- The puller is installed so that its slots fit into the grooves of the sleeve
- The whip's chain pounces on a big star so that the links of the chain fit tightly on its teeth, and the handle is on the right.
- Fixing the wheel with a whip, you can begin to unscrew the retaining ring with an adjustable wrench and puller. In this case, the handle of the whip and the key should form an obtuse angle, slightly less unfolded. The puller is unscrewed counterclockwise, at the same time you need to slightly pull the whip clockwise. If the sprocket teeth are badly worn, the whip chain may slide off, in which case it will have to be transferred to another star.
- After unscrewing the retaining ring, it is set aside, and the asterisks and intermediate washers are laid out in order. If the washers are stuck together with asterisks, they are carefully separated with a screwdriver.
- Sprockets and bushing are cleaned and inspected, if damage to the parts is found, they will have to be replaced.
- Experts do not recommend lubricating sprockets and bushings so as not to cause sticking of dust and sand. Lubricate only the inner surface of the retaining ring, so that the next time it is easier to unscrew
- The base of the cassette is mounted on the sleeve so that the grooves and slots are aligned. Cleaned, dry sprockets are sequentially strung on the sleeve body, alternating with separator washers, or attached to the base, which will then be put on the sleeve (depending on the cassette design)
- In cassettes at 10-11 speed, when tightening the retaining ring, you usually have to press the upper sprocket. Before you tighten the retaining ring tightly, you need to make sure that the sprockets are parallel to each other, turn the wheel
- The puller is screwed to the stop with a wrench in a clockwise direction, before installing the wheel, it is necessary to check the assembly again
The cassette is an important node of the bike and is used to change the gear ratio and shift speeds. The number of available speeds depends on the number of stars in the cassette, the range of stars is also important, that is, the number of teeth on the smallest and largest.
For mountain bikes, the upper number of the range must be larger than for road bikes, the more complex the route, the greater the range and the greater the number of stars required. Cassettes also differ in material, design, their price depends on it. When choosing a cassette you need to focus on the type of bike, riding style and routes of travel. The resource of the cassette is on average 10-15 thousand km, while it needs care, cleaning from pollution.
Where can one buy?
The range that the modern market offers is quite large. There are many lesser-known manufacturers that produce the same type of equipment of dubious quality. In this case, the stated characteristics make you think that the bike is equipped with everything necessary. In fact, it turns out that the purchase will not meet the requirements.
Make a purchase is best in stores that specialize in the sale of this technology. In this case, there is a guarantee to purchase a quality product and further improve it, as needed. Choose and purchase a decent bike, high-quality parts, and cycling clothing, we recommend in the largest European stores: chainreactioncycles.com , wiggle.com .