achoo

Were those roads chip seal? Or otherwise rougher than normal?

I use 25s on my rear exclusively, and use 25s as front for training and 23s up front as a race tire. Sometimes I'm lazy and don't feel like swapping for a non-race, and I'll keep the 23 front on. There are some local roads I won't ride with a front 23 - I want to keep my fillings in my teeth.

Black wallnut 

Yes most of them were chip seal roads. There are large differences between smooth chip seal and rough chip seal. Size of the rock, type of the asphalt, amount of rolling and probably some other factors as well. Most all my riding is on chip seal of a fairly smooth variety. Rock between 1/4 and 3/8" with rounded edges. Still a far cry from hot mix layed asphalt or tarmac. I'm still rolling the 23 on the front of my bike, it just keeps going and going. My Roubiax soaks up road buzz.