tire pressure hot/cold?

[Ferris Leets]

Every manual, tire and conventional wisdom tells you to check tire pressure cold.  As you ride the temp increases and therefore the pressure.  Somewhere I read that one way of verifying correct tire pressure was to check and the ride for 1/2 hour.  Then recheck and the increse should be about 2 lbs. 
       Okay, now my question is.  Why not check the tire pressure at operating temperature rather than ambient?  Just seems to me it would make for a more consistent riding pressure.

[Brad]

Good information here.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=73

[Ferris Leets]

Good article but not really anything new to me.  I still wonder why not set the pressure at operating temp?

[Bone]

If the pressure is at an unsafe level would you ride the motorcycle until the operating temperature is reached ? Cold conditions would take even more time to reach that higher temperature.

[fudgie]

Seems like a low/flat tire would warm up faster.

[Bobbo]

Good article but not really anything new to me.  I still wonder why not set the pressure at operating temp?

Most likely because operating temperature is different for each tire and application.  It is more consistent to use a standardized temperature.  Also, if your tires were very low or high, getting it to operating temperature might be dangerous!

The general rule is 1 PSI rise for every 10 degrees F of temperature.  This is for the volume of a typical car tire, so a motorcycle tire might be slightly different.

[Ricky-D]

Tire manufacturers take warming tires into their calculations when determining the cold tire pressure.

Since not everyone drives the same, under the same conditions the difficulty of determining hot tire pressure is extremely difficult.

The tire manufacturers are more concerned with the tire operating under low tire pressures since that is the condition where the most damage to the tire can occur.  You should look at the recommended tire pressures as a minimum figure. 

Maximum tire pressures are always conditioned with a maximum load and are pretty much at the end of the safety range which is probably a factor of two or greater.

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[Ferris Leets]

My question is still the same.  The responses I have gotten really do not answer the question.  Manufacturers recommendations are not the question. 

[CajunRider]

The simple answer???  Liability.  

Nobody (be it the tire manufacturer or a mechanic) wants to be sued because someone tried to drive a flat tire for half an hour to warm it up so the pressure could be checked... and half way through the warm up, it exploded causing a crash and deaths.  

You can thank lawyers for that.  

[RonW]

If you buy yourself a decent magnifying glass you would see for yourself that the air molecules are bouncing around in their still heated agitated state.