Originally Posted by
Pratt
Not that will in any way settle this debate, in fact, probably the reverse, but you can find out if more or less pressure is faster in your tires by "brushing" with a friend.
Start out coasting eat the same speed, next to each other on a nice down hill. Then repeat with more or less pressure in your tires, and no change to your friend's. Similarly, keep the weights, positions, etc. unchanged from trial to trial. You should be able to see the effect easily. You can call sprinting back up the hill for another run "intervals."
This is wisdom!
Actually, I bought my first Compass (now Rene Herse) 28mm tires for two features, lightweight and had tan sidewalls in a world of black sidewalls, in hopes of duplicating (or what I remembered) from an
old set of Clement (original) hand made cotton clinchers that were truly great. I had been using Continental GP4000SII tires in 28mm. I had not read any of the Rene Herse or other testing articles.
At the first ride of our small vacation group, I received comments on the 'old school' tires. However, as we rode, I found that in a coasting downhill, I would always end up passing the other riders and coast longer on the flats. So we did some deliberate comparisons, with similar results. Another rider with a similar sized bike, who was running 25mm tires, switched bike with me and we still had the same outcomes. While I like to think I am good at adjusting cup and cone bearings for smooth performance, I fully doubt that was an issue. We later in the week did the same, admittedly non-scientific, tests using my alternate wheelset that had the Continentals 28s, with similar results, but not as much difference.
I use the Rene Herse for most of my riding, but if it is damp or misty, I use the Continentals as they feel more grippy in corners in damp or wet.
When we got home, that rider bought a set of 25mm Continentals GP4000SII since they were more readily available locally and were in black.
Now there are more tan-walled tires, and more supple casings, but my experiences with Rene Herse keep me going back. I feel the same about the Continentals, and will probably replace the 28mm GP4000SII with 32mm GP5000s.
As always, my opinions and non-scientific observations. so in this case, truly a YMMV.