Deflating Tires Post Ride

Not necessary.

Even in a hot car, I think if PV=nRT, you are looking at maybe a 50 degree increase in temperature F which is 30 K i.e. at most a 10% increase in pressure.

That's likely not enough to make your tire pop.

So no, don't bother.

Correct and fixed.

I thought the same thing.  However, when I was picking up my bike and gear after my last race everything had been sitting under the sun for a couple hours.  It was at least 100 degrees and a cloudless sky.  Another racer who had just picked up his bike was wheeling it away and I heard/saw the tire give out.  There was a loud pop/whoosh sound.

Could be that the tread or sidewall was weakened already and sitting in the sun was enough to put it over the edge.

Could have been a pinch flat or some other issue too.

Yep that happened to my bike sitting in transition at last years Heatwave Triathlon.  I did the relay portion and after my runner took off about 5 minutes later my tube popped.  I couldn't believe it until I heard another one pop on the other end of transition.  It got to 102 that day.

All I know is that we just finished a summer with frequent highs in the 100-110 range, my bike in the cab of my pickup-much hotter all day and no flats, nor anyone I know of.

Someone on this board has quoted pascal's law or some such thing that is beyond me, that explains why the heat isn't causing the flats

I was in Vegas when I saw this happen.  Like I said before, I don't think a perfectly good tire will just blow out due to a little heat.  Maybe the sidewall got cut, or something similar during the race.

Combine that with the fact that everyone aired up their tires at 5:30am when it was probably 70 degrees outside, and the bikes sat on blacktop at T2 for a couple hours in 100 degree heat (and I imagine black tires on blacktop under a cloudless sky will be a little hotter than the surrounding air temperature.)

Yep we (I) have gone thru this before.  If the small increase in pressure makes your tire pop, it was going to pop anyway.

0F = 255Kelvin  100F = 311 K

So an increase of 13.9%.  So a 100psi tires will now be 113.9psi.  And that's a swing of 100 degrees.

Been cycling in FL my entire life.  Have never deflated my tires after a ride.

This does not make sense either.  Deflating and re-inflating the tube is going to put it under more fatigue stress than maintaining it at a constant pressure.

Exactly!

I live in the desert and it's not unusual for me to put 120#'s in my tires when it's in the 70's before I leave and well above 100 when I'm out riding on black asphalt roads. I've also left my bike in the car in extreme heat and have not had one pop yet. The extreme heat will over time take a toll on rubber and similar synthetics over time. It won't cause a properly inflated tire/tube to explode with a 50 degree temperature increase. What I think is even worse is leaving something exposed to the direct sunlight out here.