Tire Pressure
Diagnostics

It starts before the ride, because that is when this tool earns its keep. Open the page in the morning, and the first thing it gives you is the pre-ride verdict, read off the caps that have been reporting all night while the bike sat. Green means both tires are where you set them. Go ride — but say the front tire shed air overnight, a slow leak at the bead or a nail you picked up yesterday and never saw. The page says do not ride, in plain words, and it says it before you have your boots on. That is the whole reason this tool exists. The warning comes first, at the house, not at freeway speed.

Check the tire cold, always cold. Pressure climbs about a pound for every 10 degrees the tire warms, and a good ride adds 3 to 5 pounds on its own. That rise is expansion, not new air, and the page knows it, so it judges you against your cold targets and never tells you to bleed a hot tire down to a cold number. Riders have chased that ghost for years. You will not.

On the road, the caps keep reporting, and the page watches the shape of the ride. A tire that holds its curve is a healthy tire. A tire that sheds steadily — a pound and a half gone from where the ride started — gets flagged as a suspected slow leak while you are still riding it, not when you find it flat in a parking lot. And when something does go wrong, the verdict speaks plainly. Within 2 under to 3 over your target: in spec, ride. 2 to 5 under, fix it before the next ride. Air is free. 5 or more under, do not ride, because a front tire that low steers vague, brakes long, runs hot, and eats itself alive. And a blowout on two wheels is not a story anybody tells twice.

Over the weeks, the record underneath does the quiet work. A tire that loses a pound a week, every week, is telling you about a valve core, a bead seat, or a tread working a nail in deeper. And the page can show you the pattern because it remembers every morning you ever checked.

That is the diagnostic live: not a number on a screen, a verdict before the ride, a watchman during it, and a memory after it.

The line at the top says it plain: the most overlooked check on the bike, and the one that matters most.

On the real tool, little Bluetooth sensors screw onto your valve stems in place of the caps, and they report pressure and tire temperature live. This screen is the phone view those sensors feed.

First block: the status. When it says checking tires, the panel is reading both sensors. Right under it sits the ambient air temperature, the temperature of the air around the bike. That number matters, because every pressure on this screen is judged cold, against the morning's air.

Next, your two tire cards, front and rear. Each card shows you four things: the tire's own temperature, its pressure in PSI, its status (at spec, under, or over), and the words PSI cold, reminding you this judgment is a cold judgment. Beside the cards is the zone strip, the law of this page. Within 2 under to 3 over your target: in spec, ride. 2 to 5 under, or 3 or more over: fix it before you ride. 5 or more under target: do not ride. Full stop.

Under the cards, the Pre-ride check: your verdict in one glance before you roll. And below it, the chart: two lines, your front and rear pressures, with dashed target lines running across. If a line sags away from its dashed target over time, you're looking at a leak drawing you a picture.

Now, Set the Scene. On this preview, these sliders stand in for your sensors. On the real tool, the numbers come straight from the caps. The first slider sets the front tire's pressure, the second sets the rear, the third sets the ambient temperature. Two things to try. Drag the front down to 28 and run the Pre-ride check, and watch the verdict change. Then start the rear slow leak and leave it alone: once the rear has shed about 1.5 PSI from where the session started, the tool flags the leak by itself. That is the product working exactly as designed.

Below that, About this reading, and this is the part to remember. A front tire just 5 PSI under spec gets vague steering, longer braking, and a hot, fast-wearing carcass. Run it long enough and it's a blowout risk. And always judge pressure cold: a warm tire reads 3 to 5 PSI high, so a good hot reading can hide a low tire. Pressure climbs about 1 PSI for every 10 degrees the tire warms, and riding adds 3 to 5 PSI on its own. Never bleed a hot tire down to the cold spec; you'd ride home under-inflated. Set your pressures cold, in the morning, before the bike moves.

Then, how to read the gauges. At target means a full contact patch, steering and braking as designed. 2 to 5 under: top it up before riding. 5 plus under: do not ride; pinch-flat and blowout country. 3 plus over: smaller contact patch, harsher ride, less grip, worst in the wet, so bleed it down cold. And if you're losing about 1 PSI a week, that's a slow leak: check the valve core and stem first, then the bead seat, then the tread for a nail.

Last, about the sensors themselves. They screw on with your fingers, no tire removal. They broadcast live while you ride, and this screen alerts on a low tire mid-ride. The coin cell in each cap lasts a year or better, and metal valve stems are recommended. But check cold anyway. The sensors make the morning check effortless: glance at your phone before you roll, not after the first corner feels wrong. That's the whole tool.