Before each ride there's a little task I perform. I put the squeeze to both of my tires, checking for proper inflation. No need for a gauge, I just go by feel. It's a good habit to have, and helps lessen the chances of flattening.
Over the years, I've altered my views and practices when it comes to air pressure. In the past, if a tire called for 120 psi (pounds per square inch), I'd go for the maximum — and sometimes even beyond. It didn't matter if it was a road tire, mountain bike tire, or gravel bike tire.
Now, most times I tend to stay 10 psi below what is recommended by the manufacturer. For example, most of my 23 mm (millimeter) tires say 120 psi on the sidewall, so I put in 110 psi.
But bike makers, of late, have instituted design and component changes, thus affecting air pressure norms. One of the biggest differences is that bicycles are coming with wider tires. This is done in order to make riding more comfortable — by absorbing bumps — and to reduce flats, but still allowing cyclists to roll along just as fast and as smoothly. The advent of disc brakes has made the width factor a whole lot easier to accomplish. Taking a look at the new 2021 Trek road models, most are equipped with 25 mm and 28 mm tires, but some go all the way up to 32 mm and even 40 mm.
With an even wider tire, you can go with less air pressure. My Trek Domane has 25 mm tires, which can take up to 120 psi. But I keep it at 100 psi and I am quite happy with its performance. My Specialized Crux cyclocross bike sports 38 mm tires; maximum 100 psi, but I run 80 psi. So even I don't always stick to my 10 psi-less rule.
Anyway, different bikes, different tires, different riding conditions, different air pressures. I guess my advice is try different levels of psi and pick the one that feels right for you. And give those tires a little pinch.
Another good read
I thoroughly enjoyed the book "Balmamion" by Herbie Sykes (Rapha, 2020). It's about cyclist Franco Balmamion, the last Italian to have won successive editions of the Grand Tour stage race Giro d'Italia (1962, 1963). He was a relatively unknown pro prior to, and after, his victories, and the author goes into great detail to explain why.
The 224 pages contain a description of what happened in each stage — 21 in total — in the 1962 contest and the book is interspersed with longer stories on the main protagonists. It also offers a review of how the "Silent Champion" prevailed again in 1963. As always, the use of old photographs was very pleasing. I highly recommend "Balmamion," although it was impossible for me to pronounce the Italian names.
I would like to add that obtaining books through Rapha (rapha.cc), I believe, has proven to be advantageous. Every one I have selected has been a stellar read; it's almost as if they are acting as a clearinghouse for excellent writing and photography. Weeding out the junky stuff.
I just received another book from Rapha titled "Pantani was a god." I'm looking forward to pedaling through the pages. Be safe out there!