Inner tube

An inner tube holds the air inside the tyre on wheels whose rim is not airtight – mainly spoked rims. That is why tubes are standard on motocross, enduro and classic motorcycles, and on many small bikes and scooters.

Choose the tube by tyre size (for example 110/100-18) and with the right valve: straight (e.g. TR4, TR6) or angled to suit the rim hole. Off-road, a heavy-duty tube copes much better with low pressures and rocks.

When fitting, dust the tube and tyre with a little talc, inflate slightly so the tube straightens, and take care not to pinch it with the tyre levers. At low off-road pressures a rim lock stops the tyre turning on the rim and tearing the valve out. Fit a new tube when you change the tyre.