A tire gauge is a small tool with a big effect. A few psi changes how the bike steers, how the tire wears and how it behaves in the rain. Most gauges are reasonably accurate when new, but they drift and get dropped. Check yours against a known good gauge.

SystemWorkshop equipment
Typical materialsSteel or plastic body, bourdon tube or digital sensor
What to checkAccuracy, seal at the valve, scale range and battery
Technical schematic of Motorcycle tire pressure gauges
Fig. 01 — working principleIndoBikes drawing

What it is for

The gauge measures the air pressure inside the tire. It connects to the valve and reads the pressure. A good gauge holds the reading after removal so you can read it without crouching.

Motorcycle tires use relatively low pressures, often around 2.0 to 2.9 bar depending on the bike and load. A gauge with a wide 0 to 10 bar scale is less precise at those values than a dedicated low-pressure gauge.

How it works

A mechanical gauge uses a bourdon tube or a piston that moves under pressure. A digital gauge uses a sensor. Both need a good seal at the valve to read correctly.

Pressure rises as the tire heats. Check cold pressure before a ride, not after. The manual's figure is for cold tires. A hot reading will be higher and should not be used to set pressure.

Types and variations

  • Stick gauge. Cheap and simple. Less precise and easy to lose.
  • Dial gauge. A clear scale and a hold valve. Good for home use.
  • Digital gauge. Easy to read. Needs a battery and can drift.
  • Inflator gauge. Combines a gauge with an air chuck. Useful with a compressor.
  • TPMS. A sensor in the wheel. Convenient, but sensors have batteries and can fail.

When it stops being reliable

  • A gauge that reads differently from a known good one.
  • A leaking seal at the valve connection.
  • A digital display that is dim or erratic.
  • A bent stem or a cracked body.
  • A gauge dropped on a hard floor.
  • A TPMS sensor with a flat battery.

Choosing one

  • Choose a gauge with a scale suited to motorcycle pressures.
  • A dial or digital gauge with a hold function is easier to use than a stick.
  • Check the accuracy against a known gauge.
  • For a bike with TPMS, check the system's accuracy occasionally.
  • Keep a gauge on the bike and another in the workshop.

Range and compatibility

  • Check pressure cold, with the bike upright and the tires cool.
  • Remove the valve cap and press the gauge squarely onto the valve.
  • Read the value and compare with the manual.
  • Refit the cap.
  • Check both tires, not just the one that looks low.

Accuracy and care

  • Store the gauge where it will not be dropped.
  • Replace the battery in a digital gauge.
  • Check the seal for cracks.
  • Compare with a known good gauge occasionally.
  • Do not use a gauge as a valve core tool.

Safety and limits

Underinflated tires overheat and can fail. Check pressure before a long ride.

Do not set pressure from a hot tire reading. Check cold.

A TPMS warning is a reason to stop and check, not to ignore.

Questions

How often should I check tire pressure?

At least weekly and before long rides. Tires can lose a little air over time.

Should I check pressure hot or cold?

Cold. The manual's figure is for cold tires. Hot pressure is higher and should not be used to set the value.

Are digital gauges more accurate?

Not necessarily. A good dial gauge can be very accurate. Check against a known reference.

Can I rely on TPMS?

It is convenient, but check with a gauge occasionally. Sensors can drift or fail.