If your like me then your have probably have come across a foot pump when you have had to tackle not so tough tasks of inflating beach balls, or air mattress but have you ever thought about tackling a car tyre.
Just imagine you find yourself stranded in the middle of nowhere with no petrol stations near you, your mobile phone has no signal and the electrical inflator is broken. In such a situation you may want to kiss that foot pump gathering dust in the boot since it could be a lifesaver.
What is a Foot pump?
A Foot pump is a manual pump designed to deliver a supply of compressed air for use in inflating tyres, sport balls or other inflatables. A foot pump used to be an essential car add-on to have in your boot as tyres rarely require more than a couple of pounds of air.
So what are the advantages of using a foot pump: well there are no cables to trip over, and it will even work if the car battery is flat, there is nothing to plug in and they come in cheap too. Given their mobile nature, car tyre foot pumps are also excellent for filling in tyres which are away from car, like a spare wheel.
Foot pumps do not generate high air pressures so they don’t tend to work as well for narrow bike tyres, but are excellent for large low pressure tyres, (car or mountain bike tyres). They are generally designed for cars but can inflate bicycle tyres also by using a brass reducer.
How does a foot pump work?
These pumps work on using pistons and pressure to generate compressed air. A Car tyre foot pump has one piston inside and two one-way valves. One valve goes to the tyre and the other to the outside air.
When the foot is pressed on the pump, the piston inside is pushed down which compresses the air inside. This compression of the air causes the inlet valve to close and opens the valve to the tyre which pushes air into the tyre.
When the foot is raised from the pump, the piston is released which decreases the pressure inside. This pulls in air from the outside but also closes the valve to the tyre.
Before you can use a pump it has to be connected to the valve on the tyre. Cars come in fitted with standard Schrader valves and the two main types of tyre valves which come with the bicycle are the Presta valve and Schrader valve.
Some foot pumps fit both types of valves but adapters are also available through which the pump can fit to any type of valve.
Double cylinder vs Single cylinder car tyre foot pumps
As mentioned earlier, car foot pumps have a cylinder with a piston inside. When you pump the piston moves and pushes in air. With the double cylinder pumps, there are 2 cylinders and hence 2 pistons.
So with each foot stroke, it moves in the double amount of air than the single cylinder pump. Double cylinder pumps are often also called rapid action twin cylinder as they are used for quick tyre inflation.
But you don’t get all this extra compressed air for nothing. Have twice the number of cylinders means twice the force required is required to make the pump work than when using a single cylinder model which is the only disadvantage associated with the double cylinder foot pump.
For an average male of about 75 kg, he would have to bring nearly all the weight to make it pump, but it is so much faster than the single cylinder that it’s totally worth the effort.
How long does it take to inflate a car tyre with a foot pump?
With some physical persistence and 10-15 minutes of foot pumping, you can inflate a tyre up to an acceptable 30psi. The 10-15 minutes is an estimation at best since using a single or double cylinder pump as well as the weight and fitness of the person using the pump will all affect the time it take. The best approach is to get your tyre up to an acceptable pressure so its possible to move the car safely and then inflate the tyre to the recommended pressure level from a petrol station machine.
Why is my car tyre foot pump not working?
Foot pumps should be stable and must come in with an attached easily readable pressure gauge. The more extended its hose the more suitable it will be as it will give better place to pump with foot. If your foot pump has gone rock solid after first few pumps, this usually means that the rubber seals just went hard. Try putting on about a tea spoon of oil on the pump shafts and on the rubber seals.
Sometimes the pump may be working fine but the connection between the pump and the tyre might not be correct. So you need to make sure that you have the connector correctly placed with the Schrader valve of your tyre. There is a little pin has to be pinned down for the air to get into the tyre. The air will not be filled in the tyre if the pin is not pressed down enough no matter how much you pump. Initially you would have to ram it on the tyre valve as you get a lot of initial resistance due to the tyre valve sticking.
Why is having the Correct Tyre Pressure Important?
So why is having your tyres at the correct pressure so important. You might be aware that ensuring your tyres are kept well maintained is very important area related to the a cars performance. Not only the handling of the car but also braking will suffer. Tyre’s not inflated to the correct pressure can cause the car to averages worse fuel consumption.
An under inflated tyre will be harder to handle as you steer while an overinflated tyre will have less grip on the road. We cannot emphasize enough how important keeping your tyres at optimal pressure level can be when it comes to road safety.
An easier way to ensure your car tyres are at the correct pressure could be by taking a trip to a local petrol station filling in from the electric machines or using a portable tyre air compressor.
What is my correct tyre pressure?
Your correct tyre pressure is determined by your car manufacturer. You can find that in your car’s manual book and also some manufacturers have put that number on the car’s door ledge or even on the tyre itself. Don’t rely on looking at the readings on the tyre.
Keep in mind that tyres should be adjusted according to the load/weight they have to carry and according to the climate in which the car has to be driven. Never go above or below a manufacturer’s recommended tyre pressures listed for the car.
If you intend on inflating a bikes tyre the most accurate tyre pressure for a bicycle will be depend on a number of factors such as the kind of the bike. More of these factors include the kind of tyres you have installed, the weight of the rider and the weather conditions.
Some experts claim that even some under inflation of a cars tyre can reduce the efficiency of fuel consumption by up to 40 percent. Furthermore, according to the US national highway traffic safety administration (NHTSA), tyres with low pressure extend braking distance by 22%.
By ensuring tyres are kept at the recommended pressure level means you that you will have good stable control of your vehicle and a higher fuel efficiency. What better way to do this than to own a handy foot pump with a gauge meter yourself in your car boot with you at all the times.
But remember to never go above or below the car manufacturer’s recommended tyre pressures listed on the tyres.
NHTSA – National Highway Traffic Safety Administration
Foot Pump – Wikipedia