I don't know what the C and O means.
We are talking some very sharp rocky backroads. Brandy just posted a picture on her biking blog of a road she was on recently that looks similar to a couple of the worst back roads we have ridden on:
http://farm4.static.flickr.com/3656/...54b4740e62.jpg
(great blog, Brandy)
We once rode downhill on a dried out creek bed too that was basically just a river rock trail through the woods.
Lots of back farm roads here that periodically get graded and bulldozed and spread with fresh chipped stone (can't even really call it 'gravel'). Sometimes they do a section and you don't discover it til you are there and can't easily turn back.
I'm really amazed that I haven't gotten more flats.
I've gotten 2 flats in about 7,000 miles, both were from long pointy glass shards.
I used to ride 700x 38's Paselas- big fat cushy things. I didn't get any more flats with either the 28 Paselas or the 25 Continentals.
Yes, the 38's did have a bit more 'cush' factor, but they were heavier too.
I never seem to have any 'cush' issue concerning the smoothness of my ride, having the 25's doesn't feel harsh to me. Maybe it's because of my steel bikes? I don't know, but I have never experienced anything I would call a harsh ride. (Except the one time I test rode an aluminum road bike for a couple of miles...I thought my fillings were going to come out!) :eek:

