I'm no expert, but on my 700c gravel bike I have WTB Nano 40's. I really like them. The tread has that very prominent center line, and to my non-roadie self they feel "fine" on pavement, yet they grip great in our CA loose, rocky, terrain as you describe (not as great as my other bike's Sendero 47s, but those are essentially MTB tires). I was kind of surprised, 'cause I had gotten to where I thought even 40c wasn't wide enough!
Last edited by pbass; 07-09-21 at 09:49 AM.