Flat Bicycle Tyre – Patch or Replace?

The cause is usually a sharp object (shard of glass, nail) or a faulty valve. To remove the inner tube: use tyre levers, pull out the tube, and locate the puncture by submerging the tube in water. To patch: roughen the area, apply the patch and press firmly (cold patch), or apply vulcanising glue and allow 5 minutes to dry. Before refitting, check the inside of the tyre for any embedded objects. Insert the tube, inflate slightly, and press the tyre bead in with your thumbs – do not use a tyre lever, as this may cause a new puncture. Inflate to the correct pressure as indicated on the tyre sidewall (usually 3–6 bar).