Step One: Look It Over
To determine how much air to put in your tire, read the PSI (pounds per square inch) recommendation printed on the sidewall. These numbers are based on manufacturer calculations balancing safety and performance.
It's best to inflate to at least the minimum recommended PSI, but try not to go too much over the max, even though you sometimes can. Different tires have different specs; a good rule of thumb is that your tires should be firm, but not rock-hard.
Now, check the tire to make sure it's correctly seated on the rim. Make sure that the valve sticks out at right angles to the rim, and that there's no dry rot (cracking) on the tire sidewalls or excessive wear on the tire surface.
Step Two: Pump It Up
Remove the plastic dust cap from the valve and place it somewhere close by, as these are easily lost. If you have a Presta valve, loosen the knurled nut completely and tap the needle gently inward to make sure it's not stuck in place (if the tire already has air inside, some will hiss out when you do this). Make sure the fitting for your pump is correct for your valve – the wider aperture is for Schrader, the narrower one is for Presta.
If there's a locking lever at the pump head, make sure it's unlocked. Slide the pump head onto the valve. Once the pump is firmly attached, secure the locking lever to fix the head in place. Start pumping, checking the pressure as you go until you reach the recommended PSI. Unlock the lever and quickly remove the pump head. If you have a Presta valve, re-tighten the knurled nut. Replace the dust cap, and you're done!
What's Your Valve? Schrader vs. Presta
Inner tube valves in North America mainly come in two varieties: Schrader or Presta. Schrader valves are fatter, with a spring-loaded pin and a plastic dust cap. They're common on less expensive bikes, older bikes, mountain bikes and utility bikes. (They're also found on car tires.)
Presta valves are narrower and springless, with a knurled nut on the valve needle that acts as a built-in valve cap. Appearing mainly on high-performance bikes, Presta valves hold higher air pressure than Schraders, and often include a useful lock nut at the valve base to hold the valve steady at the wheel rim.
Each valve type requires its own pump fitting, but most bike pumps come with a dual or reversible fitting that adjusts to fit either valve. Only Schrader valve inner tubes can be pumped up with gas station pumps, but you can buy an inexpensive screw-on brass adapter for Presta tubes that allows you to use Schrader-fitted pumps.
Latest Comments