Tire Pressure

Tire Pressure ~

One of the most misunderstood aspects of bicycle maintenance is tire pressure. Despite the abundance of advertising that hypes otherwise, pumping ever more air pressure in your tires is neither as safe nor as efficient as a balanced strategy. Tires perform best when they are allowed to contour to the road surface. They should flatten a bit in the center of the tread so they grip the surface better to increase comfort and control. A tire that is inflated "hard as a rock" will bounce off the small imperfections in the road. Not only does this decrease control, it's also very inefficient. Bouncing eats up forward motion! Also, it significantly decreases headset life and even frame life.

The following is an excellent quote from our good friends at Bicycle Info Tech:

"Don't dynamite your tires. In the last decade it has become an article of faith that the more pressure one puts in a tire, the better (that is, faster) the bike will ride. One brand of tires actually requires 140 psi. This kind of tire pressure makes the bike ride like junk. With super high tire pressures the bike bounces, transmits road shock, fatigues the rider, causes the premature failure of bike frames and components and makes the tires more prone to flats. Running the tires at 105 - 115 psi will yield a bike that corners better and gives a far nicer ride. Try it. It will still go fast."

The best strategy is to inflate tires according to your body weight. A heavier person needs more air pressure and a lighter person needs less.

Starting PSI Guidelines for rear tire (front tires get 5 lbs less air) :

Body Weight	Road	Mountain	Hybrid
under 120 lbs	85	30	50
120-140 lbs	90	35	55
140-160 lbs	95	40	60
160-180 lbs	100	45	65
180-200 lbs	105	50	70
over 200 lbs	110	55	75

The above guidelines should be modified as follows:

	If the starting guideline feels a little soft then increase 5 lbs
	If the starting guideline feels harsh or bouncy then decrease 5 lbs
	Decrease pressures 10 lbs for riding on wet surfaces
	Increase pressures 10 lbs for race quality tubular tires rather than clinchers
	Increase pressures 10 lbs for racing on smooth surfaces, particularly in time trials

Pump gauges vary quite considerably. By road feel, learn the idiosyncrasies of your particular pump.

Some specialty racing tires are designed to take higher pressures and still conform to the road surface. Inflate these tires more firmly, but still use the "bounce test" to establish your optimum riding pressure.