I carry a spare tire. I have seen people need them too often to skip it. I had an unbootable blowout recently, would have been a ride ending mess if I wasn't carrying a spare. The boots don't work all that often, from what I've seen. People carry Tyvek (think Fedex envelope) and duct tape also might be necessary. I think I could have used duct tape if it weren't for the fact that I had another 150 miles and 18 hours of riding left. My tire was a Bontrager with about 1000k on it. I put it on last year, rode the 400k and about 300k of the 600k, a 200k this year, and less than 100 miles of the fleche.