Tire pressure

Tire Pressure Doesn’t Matter for Performance. The variations are much smaller and hard to predict – they depend on the tire as much as on the road surface – so the take-home message is that tire pressure doesn’t matter enough to worry about it. Inflate your tires enough that they don’t collapse when you corner at speed, and you have found the optimum pressure for your tires. It’s that simple.
A detailed explanation of why this happens is beyond the scope of this article, but basically, on a bike, the resistance of tires consists of two types of energy losses. One is from deformation of the tire, and higher pressures reduce that deformation. The second loss occurs from the vibrations of the bike, and those increase with higher pressures. The two effects roughly cancel each other, which is why tire pressure doesn’t have a big effect on rolling resistance. In the past, researchers focused only on the tire deformation and overlooked the losses due to vibrations, hence the belief that higher pressures rolled faster.

​Read All About it HERE
It took a while for this research to become accepted, but once the professional cycling teams started testing tires with power meters on the road, they found that the wider tires, run at lower pressures, were as fast, or faster, than the narrower tires they had been running. Add to that the better cornering grip – more rubber on the road, less bouncing that can break traction – and it didn’t take long for the pros to go from 23 to 25 mm tires.
ConclusionTire pressure does not significantly affect your bike’s rolling resistance, but the casing construction of your tires does. This means that you can ride lower pressures without going slower, and that wide tires are no slower than narrow ones – as long as they have similar casings. The fastest tires have supple casings that consume less energy when they flex, and transmit fewer vibrations, creating a win-win situation. These tires roll super-fast no matter at what pressure you run them.