Originally Posted by
Steve Sawyer
That's the first time I've heard of that practice. Care to share the advantage of doing that?
From the LiveStrong website:
As with car tires, bike tire inflation is important to performance. Bike-tire engineers look for optimal deflection, or expected flexing, for the best grip, comfort, efficiency and comfort. The most important variable affecting the ideal amount of tire pressure is the load your tires need to carry. For riders who weigh more than 180 lbs., inflate to the maximum pressure indicated on the tire sidewall, recommends Michelin. For riders who weigh less than 110 lbs., inflate to the minimum pressure.
Your weight, along with how your bike distributes weight, may require you to change the air pressure in one or both tires to gain maximum performance. Depending on how your bike distributes weight, you can have between 55 percent and 65 percent of your body weight on the rear tire. If you are heavier, you may need to increase the back-tire PSI until the firmness matches the front tire when sitting on your bike
I'm running 27x1-1/8 wheels with the 27x1-1/8 tires with a max inflation of 105psi. I keep the front pressure down a tad to reduce road vibration to my hands. Most of my weight is on the rear tire anyway, and the higher inflation pressure has a
huge impact on rolling resistance. Besides, at my *ahem* heavier weight, I need the load carrying capability at higher pressures so as to avoid pinch-flats. If you don't think so, try riding with tires inflated to 75psi for ten miles, then do the same with the tires pumped up all the way (105psi in my case), and tell me which had less rolling resistance. Over 60-100 miles, it makes a big difference!