Repair guides › Wheels & Tires
Fix a flat tire
The tire gives grip and comfort; the tube inside holds the air. The tire bead hooks under the rim edge. Rim tape covers the spoke holes. Pressure is the biggest free upgrade on any bike: wider tires at lower pressure grip and roll better on rough ground; narrower and firmer is quicker on smooth pavement. Presta valves are thin with a lock nut; Schrader are car-style.
Open this job in RideLoadout▶ Watch it done
Tools
- Floor pump with gauge: Topeak JoeBlow Sport III ($$)
- Tire levers: Pedro's Tire Levers 2.0 ($)
- Patch kit: Rema Tip Top TT 04 Sport + Park Tool TB-2 Tire Boot ($)
- Spare tubes (×2, your size + valve): Continental Tour 28 All 700x32-47 Presta 42mm (2 tubes) ($$)
Compare Good, Better and Best for each tool
Steps
- Shift to the smallest cog (rear), open the brake if rim brakes, open the QR and remove the wheel. (Thru-axle: unscrew it instead.) Hydraulic disc brakes: don't squeeze the lever while the wheel is out; slip a pad spacer or folded card between the pads.
- Let all air out. Push both tire beads into the center channel of the rim all the way around: this gives you slack.
- Hook one tire lever under the bead opposite the valve, hook it to a spoke, use the second lever 10 cm away and slide it around.
- Pull the tube out. Find the cause: run fingers carefully inside the tire, check the rim tape covers every spoke hole.
- Pump a little air into the new tube so it holds shape, valve in first, tuck it inside.
- Push the bead back on by hand, finishing at the valve. Avoid levers here: they pinch tubes.
- Inflate to 20 psi, check the bead line sits evenly above the rim all around, then to full pressure.
- Refit the wheel fully seated in the dropouts and close the QR firmly (see Use a quick release properly). Close the rim-brake quick release if you opened it, spin the wheel, and squeeze both brakes before riding.
- Patch the old tube at home: scuff, glue, wait until dry, press patch for a minute.
Diagram
Sliced across, like cutting through the tireTire, tube and rim
Signs it needs doing
- Flat (pinch flat = two little slits, "snakebite" = pressure too low)
- Cuts or threads showing
- Bulge in the sidewall (stop riding)
- Squared-off tread on the rear