I'm wondering how much riding you do to get in shape for a tour. The last few summers I've just done my usual 3 days a week 30-40 miles sneaking in a 50 or 60 mile ride once a week when I get closer to my start date. This is he first year that I'm doing a multi day so early in the spring and I won't have so many miles under my belt when I go. Getting ever so close to 50 I'm a little worried about preserving my knees.