If your existing floor pump’s gauge has crapped out (it happens), you use an air compressor, or you just don’t trust the promoter’s pump at your local ‘cross race, the FLO Air Gauge is you’re solution.
It’s pricey at $199, but the custom US-made Ashcroft gauge promises a 1% accuracy across its 120psi span for a maximum discrepancy of +/-1.2psi. That’s the “percent of span” accuracy, which means no matter where on the pump it is, that’s a span of just 2.4psi.
They say most high-end pumps are +/-3%, and some cheap ones are as bad as +/-9%.
They also claim that a 1psi difference in pressure means 1-watt change in rolling resistance. Which begs the question, what’s accurate pressure worth…$200?
But wait, there’s more!
It attaches to any pump that fits a Presta valve, including handheld mini pumps. The press-on chuck has a locking knob, twist it to tighten a rubber seal inside the chuck around the Presta valve. This keeps it from slipping off, and prevents air from escaping as you get into higher pressures. When done inflating, simply loosen the knob and pull it off. The chuck’s design lets you grip it like a pistol and remove it quickly so there’s no air loss from the tire during removal.
Need to bleed air after overinflating? Remove your pump and you’ll notice it attaches on a Presta valve, too. Simply twist the valve core slightly open and tap it to release tiny bits of air until you reach the desired pressure.
The hoses are rated to 300psi and held in place by standard hose clamps, so both pieces and the clamps are easily replaceable. They also sell replaceable chucks and presta valve ends. Check their video for a closer look at the details.