In this video we’ll look at cold tire pressures
and why they’re so important for your bike. Firstly, you hopefully know what pressure you front and rear tire requires. And hopefully you know that the correct pressure is not listed on the tire. You can usually find the correct pressures on a swingarm sticker, on in your owners manual. The recommended tire pressure for our bike will be a cold inflation tire pressure – that is the pressure of the tire before you ride and the tires warm up. This is because of science. You see, air is made of gases and gasses expand when heated. So once you start riding, the actual pressure in your tires will increase. The manufactures therefore base their recommendations on a cold tyre temperature – ambient temperature has a much smaller effect on your tire pressure than the temperature generated from riding does. Let’s demonstrate. I’ve inflated my tires to the manufacturers recommendation – 36psi at the back and 32 at the front. The temperature inside is 16.2 °C and so is the surface temperature of the tires. Now, I’m going to take a 30 minute ride and measure both temperature and pressure when I get back. Now, the surface temperature is showing at 47.2 °C And my tire pressure is now 42 psi – that’s an increase of 16% in pressure. Now imagine if you went adjusted your tire pressures during a ride when the tires were hot. If I reduce the current pressure down to 36 at the rear and 32 at the front, let’s see what happens after they cool down. Now that it’s cooled, the air in the tire as contracted. And because I adjusted my tires at a hot temperature, they’re cold or resting pressure is now 22 psi. That’s neither safe, nor is it good for tire wear.