I'm doing a 3-day, 220-mile ride this weekend. The first day is 90 miles, and they have an optional 10-mile loop at the end to make it a century. Unless I feel too bad after 90 (longest I've ever ridden is 75), I plan to give a go at the extra 10. All on my hybrid (Cannondale Quick-5). I'll try to remember to report back.