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Frank Berto’s tire pressure chart, first published in Bicycle Quarterly many years ago, has received much attention. (Note that the weights are per wheel, not for the entire bike.) More about tyre pressures
Are supple tyres the way to go? Jan Heine has long been advocating the use of wider, more supple, tyres as the most effective change to increase speed and comfort without requiring extra effort. Read his thoughts on wider tyres here. Another article on Optimizing Your Tire Pressure gives a chart of pressures for different tyres and weight …