Originally Posted by
Koyote
Those pressures are a bit high for a 40mm tubeless tire. Might want to drop to, say, 35f/40r and see how it feels.
For what it's worth, I've run my 37mm tires as low as 25f/28r. At that pressure, the rear tire gets a little squirmy through corners, but still feels pretty fast.
I would think it also depends on the weight of the rider. That was my first gravel ride, I'm 185lbs and didn't want to go too low to start with. Guy at my LBS is about my size and rides at 40psi, so I figured it would be a good starting point, it worked really well for that ride.