The bicycle pump is a positive-displacement air pump type specially designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Presta. A third type of valve called the Dunlop (or Woods) valve is present, but the tube with this valve can be charged using the Presta pump.
Some basic types are available:
- Floor pump
- Frame-mounted
- Compact or mini
- The feet are operated
- Double action
- Explosion or tubeless
In its most basic form, bicycle pumps function through hand-operated pistons. During an up-stroke, the piston pulls the air through a one-way valve into the pump from the outside. During down-stroke, the piston then moves the air from the pump to the bicycle tire. Most floor pumps, also commonly called track pumps, have built-in pressure gauges to show tire pressure.
Electrically operated pumps intended to inflate car tires (as available in most service stations) can in principle be used to inflate bicycle tires if the right type of connection is available. Some such pumps are designed to cut before the appropriate pressure (much higher for a bike than a car tire), and will be far below the expanding tires. Others may not be disconnected, but provide high flow rates to fill larger tires, at more risk of inflating and blowing up bicycle tires unless stopped with a split second.
Bulky tubeless tires require an initial discharge of air to place beads, and special pumps are available specifically for this task.
Video Bicycle pump
History
No day has been set when the first bicycle pump was invented, but it is believed to have existed in or around 1887, when the first rubber or pneumatic tire was produced by John Boyd Dunlop of Scotland. The first bicycle pump consists of a metal cylinder that has a metal rod in its center. This will force air out of the cylinder and then suck the new air when the metal rod is pulled again. Many modern pumps use very similar methods, while some others, such as electric pumps, use automatic pumping mechanisms.
Maps Bicycle pump
How it works
The bicycle pump presses the air. When the cylinder is compressed, the air is pushed to the pump tube and then to the tire through the valve, which is forced open by air pressure. When the handle is pulled again, the valve closes automatically so that air can not get out of the tire, and the new air is forced back into the cylinder so that the process can be repeated. Some pumps have gauges that show the pressure of air being forced into the tire. Once the tire is in the correct pressure, the pump valve can be removed from the tire, and the lid can be replaced on the tire valve.
There are two main types of tire valves where the bicycle tire pump attaches. These are Presta valves and Schrader valves. Some pumps fit both types of valves, while others do not, but adapters are available that allow the pump to adjust all types of valves. "All adjustable valve system connectors," also known as AVACS, enable the pump to adjust all types of valves found on the bike, and also have the capacity to fit into other universal windwave products, such as balls, rowing pools and rubber rings. AVACS features are generally available on pump models and can also be purchased as separate valve attachments. It also works by repeatedly attracting and encouraging Piston activities.
Type
There are three main types of bicycle pumps
- Standing pump
- Hand pump
- Foot pump
Upright Pump
Also known as a floor pump or track. To operate, the user lays the base of the pump on the floor, rests the foot on the base, and pulls and pushes the movement full of handles. The additional tube must connect the pump to the fill valve, which can create dead volume.
Hand pump
There are two basic types: tubed and integral. This type of tube requires a separate tube to connect the pump to the valve. It has the advantage that they are cheap, but inefficient compared to other pumps. They also have many joints from which air can get out.
The integral pump has a hole on the side with a rubber washer in accordance with the spin valve. These are often compressed to the valve by an extra lever. Because it is well covered, stiff and has a small dead volume, this type of pump is very efficient. An 8 "integral will usually pump faster than 18" tubed. This type of pump will run the risk of tearing the tube valve, especially on the presta valve.
Simple pumps have fiber fibers or plastic pistons. In the forward stroke the air pushes the cup side against the cylinder, thus forming the seal; it provides its own valve. Then this piston can push air out of the hole at the end.
Some of the most efficient pumps are double action pumps. By sealing the pistons in a cylinder at both ends, they can force air into the tires on both strokes.
Pumps can be attached to a bracket on a bicycle frame, either a clamp, a screw, or a braided fault, or they can be carried in another basket or bag on a bicycle, or they can be carried by a rider in a backpack, pocket, etc.
Mini pump
Mini pumps (or compact pumps) are usually hand pumps made very small and light, so they can be easily carried by bicycle for emergency use; they can be accommodated in a bag, saddle bag, or even including a water bottle bracket. Due to its small size, the volume of air provided by this pump is somewhat limited compared to the floor pump, so a considerable amount of pumping may be required.
Foot Pump
These pumps are often not designed specifically for bicycle use. They do not produce very high pressures so they do not work well for narrow road bike tires, but are good for large low-pressure tires like those found on mountain bikes.
Since they are designed for cars, they match the Schrader valve. If the bike has a Presta valve, a small brass silencer is required to use the pump.
Substitution CO 2
The gas-filled tube for the bike has an obscure history but seems to have emerged between the two World Wars. One story says they were made "by a rider after seeing a cafe owner refill the beer he ordered from a carbon dioxide bottle."
Pumps generally use liquid gas that can not be replaced at home. A newer, more successful version uses cartridges that are sold initially for chiffon drinks. A lever destroys enough cartridge and gas to exit the tire.
Modern gas pumps are often used by mountain bikes or road cyclists who need to save weight, and to save time if they are stabbed during the race. They can either be a one-time pump or pump that can be installed with replacement cartridges. Most pumps use carbon dioxide and 16g CO 2 tubes threaded standard. Carbon dioxide leaks out of the rubber tire faster than air - despite its larger size, the CO 2 molecule is slightly soluble in rubber and the tires can be flat in a few days.
Electric pump
The twelve-volt air compressor made for car tires is also compatible with bicycle tires. A portable jump starter for a car can sometimes be used to power this type of pump. Even a non-standard 12-volt do-it-yourself (DIY) electric system especially for bicycle lighting is sometimes used to power this pump when a lighter cigarette container is installed. The main advantage for electric pumps is that recently take up less space than hand or foot pumps, which makes them suitable for bicycles equipped with a 12-volt DIY power system to use when the cart space is of the essence.
Tire pressure
The tire pressure rating is usually stamped somewhere on the side wall. This may be in psi (pounds per square inch) or bar. The pressure rating can be indicated as "Maximum Pressure," or "Inflate to..." And will usually provide ranges (for example, 90-120 psi, or 35-60 psi). Expanding to a lower number in the pressure range will increase traction and make travel more comfortable. Expanding to a higher number will make the journey more efficient and will reduce the chances of getting a flat tire but there should be a stronger boost.
Output pressure
The maximum pressure, or how much air the pump can pump into the tire, is an important consideration. The pump must match or exceed the specified air pressure that can be handled by the tire. If the maximum air pressure is too low, it will not be enough to inflate the tire, no matter how hard it is used.
See also
- Valve stem
References
External links
Source of the article : Wikipedia
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