Originally Posted by
Koyote
This.
If your 'gravel' is really just smooth-ish dirt roads, and you don't regularly ride in mud and other nasty conditions, then a smooth 38-40mm tire will be perfect.
I’m going to politely disagree and agree at the same time. Until April 2021, my gravel ride was 2015/16 vintage and cleared 35s max. I rolled 32mm slicks on it (inflated to 34), and they were perfect for exactly the conditions you describe. When I got a “modern” gravel bike that would clear 47s, I started on 38s and eventually moved to 42s with a slick center section. The comfort was sublime and nothing I want to reduce, but the 32s on the older bike still roll faster on pavement, and aren’t uncomfortable. I’m split on which is actually better…one is faster, and one is more comfy, but the differences are minimal.