Even though they're all geared pretty much the same, they all feel different . If I'm doing a REALLY hilly ride, or need to carry a bunch of stuff, I'll grab a triple. Really bad roads? Bigger ,softer tires. No mercy training on the Viner singlespeed. Cadence work with a corncob freewheel. The Bianchi makes me feel like Fausto Coppi. And , of course, I have at least ONE that has good old track pedals for when I don't feel like walking funny...