I am set on riding my age in miles for a Birthday ride, but I have done so with modifications. Since it is my birthday, I get to do what I want. November birthday and it can be downright cold on the exact birth date, but there is usually a day close that will work. Wind can be a problem around here, so my route is one way, with the wind. My wife drives to meet me at the end, which is close to a winery and B&B/hotel (by design). And Happy Birthday to me! To me, the birthday ride is a mark of time. Even with health concerns, I rode 5 centuries last year, so the modified BDR is not a cheat in those terms. There will possibly come a day where I will need to ride my age in true miles to keep the spirit of the ride intact. For now, I am content with it as is.