distance vs time

[Eden]

I believe both are equally important, again, depending on what you are training for. As stated, longer rides are typically more about getting in the miles and pacing yourself reasonably to finish the miles. Shorter rides can a good time to go for it and finish the ride as quickly as possible. Both types of rides build your riding skills over all.

Certainly rides of all types have their place- but its a question of when you do these kinds of rides. The question was about base building and in the off season when you are putting in base miles you want to avoid hard riding. Short rides are still in. Some of my base season rides are as short as 1/2 hour or 45 min (usually a basement spin.... weather and darkness).
A little bit of hard riding isn't going to kill you, or hurt your training that much, but you should try to not do it regularly. Base training isn't really about learning how to pace yourself or just about finishing miles. You're trying during this time to build up your endurance, train your metabolism, and build up all sorts of nice little blood vessels to feed your muscles that I've heard zone 5 stuff breaks down. No one is saying never do a hard fast ride, just save the hard rides for later when you are in a build phase.

Yes - a lot of people, especially enthusiatic beginners can find base training to be frustrating and boring, but it does make a big difference when it comes to the next year. You see people who ride really hard all winter really fizzle early in the race season. Yeah, they do great the first couple of races, then nothing..

Now if you are just riding to ride, and you aren't training for any specific event/reason, then you might not have a reason to periodize - so sure ride how you feel.