Originally Posted by
cyccommute
I've got to disagree. I've ridden sections of the C&O a few times and never found it "punishing". It's a bit rougher than most trails but it's not exactly rocky or even that rough. Perhaps my perspective is colored by mountain bike experience but I found lots of trails in the eastern US that I've ridden on a loaded touring bike that were rougher.
Only ride where I got saddle-sore from bumps was C&O ride way back in high-school on a thinner-tire bike. C&O doesn't have massive bumps but they're pretty constant. One might like the challenge of riding on a thin-tire bike but otherwise why not go comfy w/50 mm tires?