How to Check and Inflate Bike Tires

How to Check Tire Pressure

1. Squeeze the tire’s sidewalls (side edges) toward each other as hard as you can. (Don’t squeeze the part of the tire that touches the road, which tends to be rigid and can mask low air pressure.)
2. If the sidewalls squeeze together easily, the air pressure is low, and the tires need to be inflated. If the sidewalls resist being pushed in, the air pressure should be fine.

How to Inflate Bike Tires

1. Prop your bike against a sturdy wall.
2. Rotate one wheel so the valve is parallel to the ground, on the side away from the main part of the bike frame. This position (circled below) lets you access the valve easily without the fork getting in the way.
    
   
3. Place the socket on the appropriate end of the pump (Presta or Schrader type) directly over the valve. If the tire is especially low on air, the valve may wobble or bend as you try to put the pump socket in place. If this happens, make the valve stand up rigidly by placing your thumb on the outside of the tire just behind the valve. Since the tire is low on air, you should be able to feel and support the base of the valve through the tire.
    
   
4. Some pumps have a small lever you have to lift so that air flows through the pump into the tire. If your pump has a lever, pull it up once you’ve covered the valve with the pump’s socket.
    
   
5. Check the tire’s sidewalls, where the tire’s maximum psi number is written.
6. Begin pumping air into the tire (this is easiest to do if you’re standing up).
7. Watch the psi meter as you pump, and stop pumping once the meter reaches the maximum psi. Overfilled tires can pop or become more prone to flats, so never inflate beyond the maximum psi.
8. If your pump has a lever, press it back down and pull the socket directly away from the valve to release the pump from the tire. Otherwise, just pull the pump away from the valve.