Realistic options
Strictly speaking, you need some source of compressed air. The realistic choices are:
- A powered air compressor, such as one at a service station, a bike shop or a garage.
- A CO2 inflator and cartridge.
- Borrowing a pump from another cyclist, a shop or a neighbor.
- An electric mini pump, if you own one.
Blowing into the tire by mouth is sometimes mentioned, but it does not generate useful pressure, so it is not a practical method.
Using an air compressor
A compressor can inflate a tire very quickly, which is both useful and risky for narrow bike tires.
- Check which valve your tire has. Schrader valves fit most compressor hoses directly. For a Presta valve, unscrew the small nut and use an adapter or a compatible hose head.
- Add air in short bursts, not continuously.
- Check pressure often, ideally with a separate gauge. The gauge on some compressors may not be accurate, and the range is meant for car tires.
- Stop well before the maximum printed on the tire sidewall.
If you only need to get home, partially inflate and ride carefully, then fix the pressure with a proper pump later. For help finding a good pressure, see how to inflate a bike tire properly.
Using a CO2 inflator
A CO2 inflator is a small head that screws or pushes onto the valve, with a cartridge that releases gas in seconds. It is popular for roadside flats. It is easy to overshoot the pressure, so read our CO2 inflator guide before using one. Cartridges are single use, and CO2 tends to escape through rubber tubes faster than air, so many riders re-check pressure later.
Other options
- Borrow a pump: a passing cyclist or a nearby bike shop will often help.
- Electric mini pump: a small rechargeable pump. Battery life and top pressure vary.
- Sealant in an aerosol can: some products inflate and seal in one go, but they are typically intended as a temporary repair, and they can make a later tube patch messy. Follow the product’s instructions.
Why the tire may not take air
Several PAA-type problems come down to the same few causes:
- The valve is closed or blocked. Unscrew a Presta nut and press the tip.
- The pump head is not sealing. Reseat and lock it.
- The tire is off the rim. If the bead has slipped out of the rim, air escapes as soon as you pump. Deflate it fully (see how to safely deflate a bike tire), refit the bead evenly all the way round, and try again.
- There is a large puncture or a damaged tube. Air will not stay in. You will need to repair or replace the tube (see why your bike tire keeps going flat if it keeps happening).
- Tubeless tires with a loose bead often need a burst of air, not a steady flow. See seating a tubeless tire with a hand pump.
After you inflate
Get a gauge reading as soon as you can. Compressors and CO2 can both produce more pressure than intended. The correct pressure is a range printed on the sidewall.
FAQ
What can I use if I do not have an air pump? A compressor, a CO2 inflator, or a borrowed pump are the practical options.
Do you need a gauge on a bike pump? It is not required, but it is much more reliable than guessing, and it helps avoid overinflation.
Why is my tire not taking air? Look for a closed valve, a poor pump seal, a tire off the rim, or a puncture.