Pumping Up Tires

Bike tires gradually lose air pressure, and riding with under-inflated tires makes you work much harder, wears your tires out faster, and makes it much easier to get a flat tire. Here's what you need to know.

Bike tires gradually lose air pressure, and riding with under-inflated tires makes you work much harder, wears your tires out faster, and makes it much easier to get a flat tire. Here’s what you need to know. 

How Often 
Check your tire pressure and re-inflate about once a week. (If you ride less than once a week, re-inflate every time your ride.) 

What You Need

  • A floor pump with a pressure gauge is ideal.
  • If your pump has no gauge, you can purchase a bike tire gauge from a bike shop. (Note: Pressure gauges for car tires may not work well for bike tires due to valve and/or pressure differences.)
  • If your bike pump only works with Schrader valves and your tires use presta valves (see below), you may need to purchase a Presta adapter from a bike shop.

Find the Pressure Rating for Your Tires 
Your tire’s pressure rating is stamped somewhere on the sidewall. It may say "PSI" (pounds per square inch), "Maximum Pressure," or "Inflate to . . . " and will usually give a range (for example, 90-120 PSI, or 35-60 PSI). Inflating to thelower number in the pressure range will increase traction and make your ride more comfortable. Inflating to the highernumber will make your ride more efficient and will decrease your chances of getting a flat tire. 

Pumping Schrader Valves 
tube with Schrader valveSchrader valves are the same type of valve that car tires have. Inflate as follows:

  • Remove the cap on the valve.
  • Press the head of your pump firmly onto the valve, and push up the locking lever to form an airtight seal.
  • Inflate the tire to your desired pressure within the recommended range.
  • When you are done inflating, unlock the lever (push it back down), and quickly pull the pump head off the valve. You will hear a little air escape.
  • Re-install the valve cap.

Pumping Presta Valvestube with presta valve

  • Unscrew the cap from the valve.
  • Unscrew the top of the valve (it is not removable).
  • Push the pump head all the way on to the valve and push up the locking lever to form an airtight seal.
  • Inflate the tire to your desired pressure within the recommended range.
  • When you are done inflating, unlock the lever (push it back down), and quickly pull the pump head off the valve. You will hear some air escape.
  • Gingerly screw the top of the presta valve down again. Pushing down on the top of the unscrewed valve allows air to escape.
  • Re-install the valve cap.

Tips 
If you can’t get the pump head onto the valve correctly, or if air escapes, try these tricks. 

Solution 1: Use the valve-head-locking lever correctly.

Before you put the pump head onto the valve, the lever should be in the unlocked position, which looks like this on most pumps. unlocked pump
Once you have pushed the pump head on to the valvefirmly, as far as it will go, lock the pump head so the lever looks like this: locked pump

(Some pumps may have a very different locking mechanism. Read your pump’s instruction manual or experiment with its locking mechanism so you know how it works.) 

Solution 2: Make sure the parts in your pump head are configured to fit the type of valve on your tube. If your pump has two heads, use the larger fitting for Schrader valves and the smaller fitting for presta. If your pump has one, reversible head, unscrew the front cap of the valve head and pull out the two inner parts (a soft rubber cylinder, and a hard plastic object with a point on one end). 

presta alignmentFor Presta, the two inner parts should be turned so that the narrow hole on the first rubber part points out, and the pointy end of the hard plastic piece points in; these two parts should fit together snugly. 

Schrader alignmentFor Schrader, the two inner parts should be turned so that the wide hole on the first rubber part points out, and the pointy end of the hard plastic piece also points out; these two parts should fit together snugly. 

Some pump heads have heads designed to fit both types of valves without reversing the inner parts; read your pump’s owners manual. 

If your tube is a presta, and your pump head is not designed with reversible parts, or you don’t want to change the configuration from Schrader, simply use a presta valve adapter with your Schrader pump head; open the presta valve and then screw the adapter onto it. The presta adapter installs so that the threaded end is on top, like the threaded end of the Schrader valve.