The recommended pressure to inflate a tyre to is usually embossed on the tyre's sidewall, often as minimum and maximum figures rather than an exact target. There are a number of factors to consider when deciding how hard your tyres need to be
Check the valve
If the presta valve hasn’t been opened for a while release a short hiss of air to check it’s not stuck. The same process, holding the valve open longer, deflates the tyre.
Presta valve or Sports Valve
A Presta valve is locked with a tiny acorn nut, unscrew this before you inflate a tyre and press the stem down to release air.
Connect The Pump
The hose or pump connection may screw on or press on. Some push fit connections lock with a cam lever. To check the correct operation of the connection look at the rubber washer and move the lever back and forth. The the ‘locked’ position squeezes the washer, the ‘on-off’ position lets the washer relax. The rubber washer in a pump connector wears out with use. It needs to be replaced when it stops gripping valves to give an air-tight sea.
If your pump or hose has a push fit, press the connection on parallel to the presta valve to avoid releasing air or bending the presta valve stem.
Inflate a tyre - Pumping
Fully open and fully close the pump with each stroke. It’s important to press the piston right to the end of it’s travel to force air into the tyre. If you stop too soon the air in the pump will tend to compress rather than flow into the tyre.
Floor or Track Pumps
Place both feet on the rests to stabilise the pump. Open the pump fully at the start of each stroke. As you get to the bottom of the stroke you can use your body weight – rather than your arms – to force the last bit of air out of the chamber by softening your knees.
It helps if you can brace the connection between the presta valve and the pump by hooking a finger or two around the tyre or spokes. Plant your feet and try to position yourself so you can get your shoulder behind the piston of the pump.
If you’re not sure exactly how hard you want your tyres to be, inflate a tyre to the maximum recommended. If – when riding – you feel the road is shaking you about and bouncing you off the ground, it’s much easier to let a little air out than to pump more in.
Many modern pumps can be converted between Presta and Schrader fitting, by dismantling the connection and reversing the direction of parts.
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