4 ms·
American machinists converted to the "centifeet" system a long time ago. Dimensions are in "thou" and "mil" (of an inch). Meters, liters, and even Celsius are
by Steltek 3y ago
American machinists converted to the "centifeet" system a long time ago. Dimensions are in "thou" and "mil" (of an inch).
Meters, liters, and even Celsius are fine. But Pascals are the hyperinflation of pressure units. 5 psi? That'll be eleventy million pascals. Maybe if I had a bike pump that had 50kPa increments alongside Psi, I could gradually figure it out.
- cyberax 3y agoPascals are not a hyperinflation. They're 1N of force over 1 square meter. And conveniently, the atmospheric pressure is very close to 100kPa. So you can use a derived unit called a "bar" which is 100kPa. Your bike tires need to be at around 3 bar.
- Zagorath 3y ago> Your bike tires need to be at around 3 bar. Yo, what? I'm pretty sure I do my bike tyres up to about 6.5 bar. And that's down from the 7 I used to use until I heard that lower pressure creates lower rolling resistance and is better.
- mikhailfranco 3y agoNo, lower pressure has: - higher rolling resistance (energy to flex the tyre) - softer ride (but don't go so low that stones or potholes pinch the rim) - better grip (surface area in contact with the ground) So go max pressure on a smooth dry road, but go softer in the wet, or on a rough road/mountain. Similarly, the tread on the typre will also affect energy absorption. Go for smooth road bike tyres, or slick MTB tyres, on a smooth road, but obviously super gnarly for rough mountain trails.
- Zagorath 3y agoAh right my mistake, I was conflating two things. The trend in road bike tyres lately is to be wider, because wider tyres have lower rolling resistance at the same pressure. It allows you, in turn, to lower the pressure and get the comfort and other benefits of lower pressure, without sacrificing performance.
- cyberax 3y agoDouble-checked. My bike is at 3 bar. Ah, I see. You likely have a road bike, I have a mountain bike.
- timeagain 3y agoTeslas (unit of magnetic flux) have the opposite problem. An MRI—the machine with the highest magnetic field most people will ever encounter—has an operating field of 7 Tesla.
- volemo 3y agoSame with capacitance. So what? That’s the beauty of SI: just add a prefix.
- lh7777 3y agoConfusingly, "Thou" (thousandth) and "mil" (mille, Latin for thousand) are the same thing: 0.001". Thou is definitely more common, but mil persists for film thickness, e.g. 4 mil trash bags are made from 0.004" plastic film. In precision machining, you'll also hear "tenths" (one tenth of a thou or 0.0001").