Back in the day, setting your tyres up was simple; you wanted the narrowest tyre you could find and then pump it up as hard as possible. The conventional wisdom being that this would decrease rolling resistance.
However, unless the surface is incredibly smooth, e.g. a Velodrome, you’re far better running wider tyres at a lower pressure – something like a 25 or 28c at 95psi is a great place to start. Wider tyres help soak up some of the imperfections in a road’s surface, thus lowering the rolling resistance. They’re also way more comfortable and more resistant to pinch punctures due to the larger air volume.
CYCLE MYTH 4: Always use big gears to build leg strength