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Old 03-01-2009, 05:55 PM   #37
Gnarly Adventurer
Joined: Jan 2009
Location: Houston, Tejas
Oddometer: 148
Great RR Trice!!

Consider that one atmosphere is 14.7 PSI. So to take a tire from 32 PSIG (G equals Gauge the engineers tell me) to 49.7 PSIG you would have to go to space. 0 up to 10,000 feet is 2 miles. Depending on who you decide is right, space is between 50 and 62 miles up. So at most you are 1/25 of the distance to space. 1013 Millibars of pressure is the average pressure at sea level. 697 millibars at 10000 feet. 697 / 1013 = .68 So at 10,000 feet you have only .68 atmospheres of pressure, or 10.1 PSI. If you stick that same 32 PSI tire on a gauge it would read approximately 14.7 - 10.1 = 3.6 + 32 = 35.6 PSIG.

On a little YSR race bike I can maybe tell the difference between 19 and 22 PSIG on a hot sticky summer race track if playing with pressures. But on a street bike or dirt bike I would be clueless how 32 vesus 35.6 PSIG would feel!! I usually just pump em up till it looks and feels good.
shadman is offline   Reply With Quote