A lot of people mark their training by mileage but I was always taught from when I could first have considered "bike riding" to legitimately be "training" to mark it in time. Because of the vagaries of speed, and the weird circumstance that has the workouts designed to train your highest speeds producing the lowest average speeds, time is a better metric than distance. Yesterday this was brought home in sharp relief as I finished up a 58 and change mile ride on the mountain bike. In road terms, not a big ride, but in mountain bike terms, a huge ride. About evenly split between road/fire road and singletrack. It took four and a half hours and felt like a road ride that was longer than that. Now, of course, the true geeks among us will use TSS as a better metric than time.
The other day I was putting some new tires (Challenge Criteriums - freaking nice tires) on my I guess 15 month old 38s and decided that they did indeed look pretty good for their "age." But their age isn't best measured in months, since a 15 month old set of carbon race wheels should look pretty darn good indeed. These, as I've said ad nauseum, have been race wheels, commuting wheels, training wheels, trainer wheels, and whatever the heck else gets done with wheels wheels. For 15 month old race wheels, they look good but not very good. For 15 month old training wheels, they look really good. For wheels with I'd guess about 6500 road miles (plus however many trainer miles), they look fantastic.
This becomes kind of a funny thing because I see more and more people riding all the time on carbon wheels. We went out for a coffee shop/"who can go the slowest" (I'm DEADLY at those contests) ride on Memorial Day, and I don't think we saw a rider on regular alloy wheels the whole day (except among our group, in which we had plenty of them). Personally I think it's a bit over the top but I won't stop people from doing what they want to do. I have kind of an obligation to ride them, so I do. Whatever.
The point being that two or three years ago, a set of four or five year old carbon wheels would be expected to be in pretty darn good shape. They might only have had 100 rides on them, and maybe 5000 miles at the outside. Now, that's some part of a season in the life of a lot of carbon wheels. Mileage, number of rides, whatever, these have all become better metrics for evaluating the longevity of a set of wheels than age.
That was a short post for me. In aetate, brevitatis?