SmartGauge D2X

The Topeak SmartGauge D2X is a pocket-sized digital pressure gauge that reads from 0.35 to 18 bar (5 to 260 psi) on Presta and Schrader valves, with no internal parts to swap. A backlit display that rotates 360 degrees, 0.1 psi resolution and an air release button let you check and fine-tune tyres, forks and shocks.

What it is

A 56 g digital gauge that tells you exactly what is in your tyre or shock, and lets you bleed it down to the number you want. The SmartHead takes both valve types: slide the selector to Presta or Schrader, press it on, and read the pressure in psi, bar or kg/cm².

Who it's for

Riders who care about a few psi. Mountain bikers dialling in trail pressures, roadies chasing the right feel, and anyone setting up air suspension will get the most from the 0.1 psi resolution. Topeak rate the D2X for road, MTB and fat bike tyres, motorcycle and car tyres, plus forks and shocks, so one gauge covers every wheel in the garage.

Key details

• Range: 0.35–18 bar (5–260 psi), 0.1 psi resolution
• Units: psi, bar or kg/cm², switchable even after you take a reading
• Display: illuminated LCD that rotates 360 degrees, readable in daylight or darkness
• Pressure tuning: Air Pressure Adjusting Mode keeps reading while you press the air release button
• Power: one CR2032 coin cell, included; auto-on, and the screen switches off after 30 seconds unused
• Last reading alarm, and a "Lo" warning when the battery is low
• Size and weight: 11.8 x 4.2 x 1.9 cm, 56 g, engineering-grade polymer body

For an accurate reading, reset the screen to 0 before each check and hold the tyre and gauge firmly together. Each measurement can let out 1–1.5 psi, so take your reading once and adjust from there. If the valve is hard to engage, slide the selector from side to side a few times, reset, and try again.

Looking after it

Do not drop or shake the gauge, and keep firm pressure off the screen. If it gets wet, dry it with a towel straight away. Clean it without alcohol, paint thinner or other harsh chemicals, and keep it away from magnets, dust and sand. Running sealant? Keep the valve horizontal while you measure so sealant stays out of the head.