4 ms·

The amount of energy in an inflated tire is surprising... https://www.youtube.com/watch?v=1VLhLcJJefo https://www.youtube.com/watch?v=1VLhLcJJefo

by tyingq 3y ago

gosub100 3y ago
there's a whole subreddit for that (and other misadventures): /r/tiresaretheenemy
- waterheater 3y ago
  Ever seen Rubber?
- robocat 3y ago
  Apparently z-nails are inexpensive but excellent caltrops against cars and boy-racers.
andrewflnr 3y ago
To be fair, truck tires are an entirely different level than most car tires. More air at much higher pressure. I did some research on what actually happens if you try to slash a tire. A car tire is only slightly risky, but a truck tire can flay your hand.
- ponector 3y ago
  And on the next level are tires of mining trucks, like that caterpillar 797 which can carry 300+ metric tons of rocks.
- panarky 3y ago
  Please tell us more about your research. What is the safest method to vandalize car tires?
  - tyingq 3y ago
    Unscrew the inner valve stem and it's an annoyance that doesn't create permanent damage.
    - emodendroket 3y ago
      I suppose a more committed vandal could go on to do permanent damage after deflating the tires at reduced personal risk.
    - andrewflnr 3y ago
      One of the more evil variations I've heard of involves pinning a bb or pebble between the cap and valve pin, creating a slow leak that's invisible until you think to take off the cap.
  - TaylorAlexander 3y ago
    maybe a small drill bit in the sidewall
  - 00N8 3y ago
    NASA has actually looked into this & found the ideal method for safely vandalizing tires https://www.thedrive.com/news/nasa-built-a-tire-assault-vehicle-from-an-rc-tank-to-explode-space-shuttle-tires https://www.thedrive.com/news/nasa-built-a-tire-assault-vehi... (it's an RC robot w/ a drill, for testing how space shuttle tires perform when damaged)
    - andrewflnr 3y ago
      That's neat, but... at that point they must have considered just getting someone to shoot the tires with a gun at a safe distance?
bumby 3y ago
This is true for any compressible fluid. Work = -pressure * delta_volume. That amount of energy is why there are different standards for stress-testing something like a pipe, depending on the medium it's carrying. Occasionally you'll see an engineer or technician stress test a pipe carrying a compressible gas similar to one carrying a liquid. I can't remember the exact ASTM standards, but I think a compressed fluid should be tested to around 110% rated pressure and an incompressible fluid at 150%. If they use the wrong one on a compressible fluid, it's putting a lot more energy in the system. If it fails, it can be a bad day.
- abfan1127 3y ago
  this is why people shouldn't pipe compressed air in PVC. PVC is rated for 300psi (iirc). However, it derates pretty quickly in cold temperature. If 150psi of air is pressurizing PVC pipe and it ruptures, its going to be a terrible day. Where if water pressurizes PVC pipe and it ruptures, its just a little messy.

The amount of energy in an inflated tire is surprising... https://www.youtube.com/watch?v=1VLhLcJJefo https://www.youtube.com/watch?v=1VLhLcJJefo

by tyingq 3y ago

The amount of energy in an inflated tire is surprising... https://www.youtube.com/watch?v=1VLhLcJJefo https://www.youtube.com/watch?v=1VLhLcJJefo

gosub100 3y ago

there's a whole subreddit for that (and other misadventures): /r/tiresaretheenemy

waterheater 3y ago
Ever seen Rubber?
robocat 3y ago
Apparently z-nails are inexpensive but excellent caltrops against cars and boy-racers.

andrewflnr 3y ago

To be fair, truck tires are an entirely different level than most car tires. More air at much higher pressure. I did some research on what actually happens if you try to slash a tire. A car tire is only slightly risky, but a truck tire can flay your hand.

ponector 3y ago
And on the next level are tires of mining trucks, like that caterpillar 797 which can carry 300+ metric tons of rocks.
panarky 3y ago
Please tell us more about your research. What is the safest method to vandalize car tires?
- tyingq 3y ago
  Unscrew the inner valve stem and it's an annoyance that doesn't create permanent damage.
  - emodendroket 3y ago
    I suppose a more committed vandal could go on to do permanent damage after deflating the tires at reduced personal risk.
  - andrewflnr 3y ago
    One of the more evil variations I've heard of involves pinning a bb or pebble between the cap and valve pin, creating a slow leak that's invisible until you think to take off the cap.
- TaylorAlexander 3y ago
  maybe a small drill bit in the sidewall
- 00N8 3y ago
  NASA has actually looked into this & found the ideal method for safely vandalizing tires https://www.thedrive.com/news/nasa-built-a-tire-assault-vehicle-from-an-rc-tank-to-explode-space-shuttle-tires https://www.thedrive.com/news/nasa-built-a-tire-assault-vehi... (it's an RC robot w/ a drill, for testing how space shuttle tires perform when damaged)
  - andrewflnr 3y ago
    That's neat, but... at that point they must have considered just getting someone to shoot the tires with a gun at a safe distance?

bumby 3y ago

This is true for any compressible fluid. Work = -pressure * delta_volume. That amount of energy is why there are different standards for stress-testing something like a pipe, depending on the medium it's carrying. Occasionally you'll see an engineer or technician stress test a pipe carrying a compressible gas similar to one carrying a liquid. I can't remember the exact ASTM standards, but I think a compressed fluid should be tested to around 110% rated pressure and an incompressible fluid at 150%. If they use the wrong one on a compressible fluid, it's putting a lot more energy in the system. If it fails, it can be a bad day.

abfan1127 3y ago
this is why people shouldn't pipe compressed air in PVC. PVC is rated for 300psi (iirc). However, it derates pretty quickly in cold temperature. If 150psi of air is pressurizing PVC pipe and it ruptures, its going to be a terrible day. Where if water pressurizes PVC pipe and it ruptures, its just a little messy.