Materials and technologies for manufacturing rear hubs
The rear hubs do NOT differ from the front hubs in manufacturing methods and materials. Bushings are produced by casting, turning or stamping. Cast bushings are the cheapest to manufacture but also the least durable and heaviest. The most optimal metal for the bushings is an aluminum alloy. Bushings for the simplest and cheapest bicycles are made from steel. The lightest and most durable bushings are obtained from titanium alloy, but they are so expensive that they are used only in professional sports VELOBIKES.
Speed bike rear hub device
Rear hub device for sport and mountain bikes
The hub device of the rear wheel of a high-speed bicycle provides for a set of driven stars through which torque is transmitted to the wheel. There are two types of chainring set. cassette and ratchet. If the hub is designed for a ratchet, then the drum (nut) is located outside the hub and integrated into the set of stars. The ratchet itself is attached to the fork with a special thread. If the sleeve is for a cassette, then the drum is located on the sleeve itself and is attached to it using a special hollow bolt (see the diagram). The cassette, in turn, is attached to the drum through a spline connection and secured with a special nut.
Rear Ratchet Threaded Hub
Splined and threaded hubs, cassette and ratchet
It is worth adding about the disc brake rotor mounting. Here, as in the front hubs, there are two standards. CenterLock and 6 Bolt. The CL standard provides for spline fastening and tightening with a special nut. This standard is patented by Shimano. The six-bolt mount is more popular and is used by all rear hub and brake manufacturers.
Rear hub for six-bolt rotor mounting
Rear hub with CenterLock for rotor
6-bolt rotor with CL mount
Bicycle rear wheel hub
The rear wheel hub of a bicycle is one of the most complex and expensive mechanisms on a bicycle. It is the rear hub that raises the most questions for novice cyclists. And its repair or maintenance is generally like a bad dream.
The quality of the bushings depends on how much effort you spend to overcome a certain distance, in other words, the “rolling” of the bike. The rear hub is subjected to much more stress than the front, which dictates the need to make it more massive. In addition, if there is only one function in the front hub (free wheel rotation), then the rear is additionally assigned functions. torque transmission, pedal-free travel, braking functions and even sometimes internal gear shifting systems (planetary hubs).
There are a lot of companies that produce bushings for bicycles and it makes no sense to list them all. It is worth noting Shimano rear hubs, these are the most common hubs due to their high quality and wide price range.
Like the front hubs, the rear hubs may differ in materials of manufacture, purpose, production technology, weight and strength. But the rear hubs have their own differences inherent only in them. Which ones will be discussed below.
Rear Hub Types
By application, the rear bushings can be used for road bikes, high-speed bikes (mountain, touring and road). Road bikes are usually fitted with single-sprocket hubs and a freewheel mechanism. Also bushings for road workers are equipped with drum brakes, i.e. Coaster brake hub. The rear hubs for sports bikes do not have a brake mechanism, but they have a free wheeling system. In addition, the sports rear hubs are divided into cassette and ratchet.
Rear hubs with brake
Most single-speed bikes, whether road or kids, have a rear hub with built-in brakes and free-wheeling pedals. These bushings perform several of the following functions:
- Transmission of torque from the driving star of the connecting rods to the driven star of the rear hub and, accordingly, the wheel itself.
- The free wheel is driven by a sprocket. As soon as the driven sprocket stops, the wheel continues to spin and not depend on the bike pedals.
- The built-in braking mechanism allows you to brake by pedaling in the opposite direction. The essence is the same as in car drum brakes with inner pads.
The most common brake bushings are the Torpedo type. These bushings were found on most Soviet bicycles and are still used today in road bikes. On the oldest Soviet and some imported bicycles of the beginning of the last century, the bushings of the “Go” type were installed. Also in Soviet times, domestic bushings with the self-explanatory name “Rodina” were developed. The last two types are almost never found at present. Therefore, let us consider in more detail the device of only Torpedo bushings.
Diagram of the rear brake hub type Torpedo
Based on the above diagram, consider how the processes occur inside the rear hub.
- Working stroke. while turning the pedals, the drive cone, rotating with its protrude, shifts the drive rollers up, thereby jamming the sleeve body, thereby rotating the wheel.
- Free play. as soon as the drive cone stops rotating, the body squeezes the drive rollers into the grooves between the protruding ones, thanks to this process, the connection between the drive cone and the body is lost. Loss of communication allows the wheel to rotate freely through the pedals.
- Braking. when the cyclist starts to push the pedal back, the drive cone starts to rotate in the opposite direction and obliquely protrude due to friction rotates the brake cone. The brake rollers fit into the grooves of the brake drum and the brake cone is pushed into the drum. The drum is moved apart by cones on both sides, pressed against the hub body and brakes the wheel.
The Torpedo type provides the best braking option. The stronger the effort on the pedal, the stronger the braking. this ensures smooth braking.
As you know, there are only a few types of bicycle carriages. Cartridge and integrated. Both types consist of industrial bearings, which are connected to the shaft and connecting rods using a spline connection. In fact, the cartridge carriage cannot be disassembled, but if it is integrated, then it is quite amenable to such manipulation.
When disassembling, you will come across two completely identical cups, which contain industrial bearings. Pay attention immediately to their location. After cleaning and lubricating the two cups and carriage tube, they must be reinstalled where they were. As a rule, the first cause of the breakdown. This is the wrong thread position.
Tools with which you can service the carriage:
- Puller for mechanisms;
- Special wrench for pressing the connecting rods;
- Slotted wrenches;
- Set of wrenches.
Before you start removing the mechanism, you must secure the bike so that it is stationary. After that, you need to pull off the plugs, which are located on the connecting rod itself, Unscrew the fixing bolt, get the connecting rod and release here.
Repairing the carriage of a Stealth bike is quite simple. If it is cartridge, then it cannot be repaired, it is best to change it to an integrated one. In this case, the carriage can be serviced for a long time.
What roads is Stels Adrenalin intended for?
Due to poor amortization, this “bike” is intended only for urban roads at an average distance (up to 50 km per day). The front fork wears out quickly, but replacing it with a more powerful one can significantly extend its life. In Stels Adrenalin, the front and rear rims are reinforced. Therefore, for a while, one cannot help but worry about their curvature.
In order to repair a Stealth bike with your own hands, you will need a little knowledge and all the necessary tools.
Do-it-yourself Stealth bike repair: subtleties and tips
Modern bicycles (high-speed, two-suspension, mountain, hybrid, road, etc.) They are distinguished by a beautiful and graceful look. They consist of complex mechanisms (disc brakes, bottom bracket, shock absorber, cassette, etc.), which significantly increase ride comfort, but need constant maintenance. In order to repair any part, you need to know what it consists of and how it works.
From this article you will learn about the complex repair of a Stealth bike with your own hands, after which you will be able to service it yourself. We will also discuss several complex mechanisms (bicycle cassette, carriage), how exactly they need to be repaired and what tools will be needed for this.
Rear wheel repair
Rear and front wheel. These are important parts of a bicycle. Why? When driving on uneven surfaces (holes, bumps, stones), it is the wheels that take most of the impacts. Therefore, timely service helps to maintain not only comfort while riding, but also speed, which is not less important for every cyclist.
In order to repair the rear wheel of a Stealth bike (with your own hands), you need to stock up on the necessary tools. For this we need:
- Wrenches (8 to 16);
- Hexagon set;
- Screwdrivers (Phillips and Hex).
One of the main problems with the rear wheel. This is an uneven rim (figure eight). Every cyclist faces this challenge. Why can a wheel become a figure eight? As we learned, more than 85% of all shocks are taken by the wheels. Most of the load falls on the rear wheel.
To align it, you need to install (perpendicular to the rim) two cotton matches, and use the pliers to loosen or strengthen the spokes. For example, if the rim is bent to the right, then the spokes on the left side need to be tightened, otherwise the ones on the opposite side will weaken.
The cassette consists of several pairs of stars, which are attached to the hub, namely to one drum. Often, the cassette contains 7 gears, which are installed on the spider. But on some bikes, for example, a hybrid, there may be 8 to 11 stars, which significantly increases the acceleration of the bike.
Do-it-yourself Stealth bicycle cassette repair consists in timely cleaning of each star from dust and plaque, as well as monthly lubrication of parts. You can clean the sprockets with a toothbrush, as it will help you get to hard-to-reach places. As for the lubricant, it is not worth using grease, petroleum jelly, or any other similar product. The most optimal substance for THESE purposes is ordinary engine oil (transmission or engine oil). If finances allow, you can purchase a special solvent for cleaning stars.
We have analyzed some of the features of DIY Stealth bike repair. Now let’s look at a specific model of the “bike”, namely Stels Adrenalin.
The bike frame is made of aluminum alloy. This model cannot be called light, because it is more intended for men than women. Depreciation leaves much to be desired, but if you use this “bike” only for short distances, for example, cycling around the city or to work and back, then it will be quite enough.
Do-it-yourself Stealth bike repair is no different from repairing second models. All the same mechanisms and designs, which can be easily removed and replaced if necessary. Almost any oil can be used for lubrication, but it is best to buy special lubricants, which will provide more reliable protection against corrosion and other contamination.
A bike. This is the most environmentally friendly mode of transport. Many argue that a daily ride on it improves well-being, raises tone and helps to always stay in great physical shape.
Do-it-yourself stealth bike repair is not as difficult as many people think. If you have at hand all the necessary tools, as well as the knowledge of how to maintain it, then this work will not seem burdensome to you. The most important thing. This is timely maintenance of the bike (lubrication of all available parts and mechanisms, adjusting the brakes and shifters, aligning the rim, etc.), and then you will not have to repair it soon.