OK, this perplexes me...

  • Before I ride, I fill my tires to 100 psi
  • Next day, before the next ride, my air pressure is consistently about 80psi
  • New tube, confident there are no links


Is there some law of physics that causes road bike tires to dissipate so quickly on psi? Is my observation unique?

I know I really should check the psi immediately after a ride...would bumps cause this big a loss of pressure??

Thoughts?