I've got four bikes built up. The tandem stays in the tandem partner/gf's garage. The carbon fiber Trek is in the bike room, mostly unused. The Dolan track bike gets used durng the winter indoor track training season. And the Rodriguez street fixie with S&S couplers (with about 60,000 km on it so far) gets used all the time, even for some of the track training. I could probably do all the riding I would want to do with just that one bike, if I were determined to go absolutely minimalist!
Luis