I once rode right over a raised manhole that I didn't see until it was about six feet in front of me on my Bianchi Volpe. Traffic had merged into one lane, and the car in front of me hid it until it was too late. It was quite jarring, and I wouldn't recommend trying it, but my wheel was fine. I'm not saying that your 'cross bike will be fine under similar circumstances, but mine was, so take that for what it's worth.