I know bike tires will lose pressure in colder seasons because the air temp causes the pressure to drop, but is the inverse true? Does bike tire pressure go up in summer due to heat?

If so, do I need to deflate the tires a bit in summer? Do bike tires ever explode because of a temperature change?

  • NessD
    2•9 months ago

    Something I thought about recently as well. I might be wrong, but is pressure not just a differential from inside to the outside? If it gets warm, air expands inside the tire, but so does the air outside, pushing back. It kinda sounds right, but I don’t know.

    • @Person264
      6•9 months ago

      I think the atmosphere can increase in volume when it gets warm because it’s not a proper closed system, so the pressure doesn’t go up in the same way.

    • @Ookami38@sh.itjust.works
      3•9 months ago

      This is easy enough to test. Take a tire and fill it. Test the pressure. Let it sit outside overnight on a cold night and test it again. The pressure will be lower.

      Consider this, as well: yes, it’s about differential pressure, but it’s also volumes. “Pressure” is the outward force from all of the molecules in the air bouncing around in a space. As temperature increases, those molecules move faster and bounce more. Since pressure is just us measuring that bouncing, increased temperature increases pressure.

      Why doesn’t the atmosphere increasing in temp balance it out? Size. The tire is SIGNIFICANTLY smaller. This means each individual molecule only has to go a little bit before it’s hitting another wall. Compared to outside the tire, those same molecules bounce off everything, some ricocheting into the tire, and others in whatever random other direction. The change in movement speed of the particles may be the same, but the change in how frequently they’re smashing into the tire is different, thus different pressures.

    • Shimitar
      1•9 months ago

      Atmosferic pressure doesn’t change as much as air density with temperature, because its not a closed system.

      Actually easier to ride faster in summertime due to less dense air in which the cycler will have to move trough…