I was jammed for time today so I rode the bike as is, which is about 90/100 (pumped up about 2 days ago). I tried to be "sensitive" - but I'm just an old klutz, and I couldn't observe much sense of the tires. But I have noticed that when the tires get soft, I have a sense the ride was smoother.

So I am going to follow FB's suggestion and experiment (although with larger changes, at least initially):

• I'll set the pressure to 70/80 and observe what it feels like on whatever ride I'm doing.
• The next day, I will pump them up 80/90 and observe on whatever course.
• And then I will go the other way and possibly try 65/75 on whatever ride.

Or maybe this will show me that I need to do it in a ultra-controlled situation: a specific course loop that I do multiple times on the same day with different pressures.

Sy, I do appreciate your input. I've used 100/110 as my standard with my Conti GP4000 25 and the Roubaix 25 tires. Getting the new 28 on the rear and observing that it seemed to tolerate less PSI is what triggered this thread.