Originally Posted by
chaadster
Lots of stuff that flexes around a lot more than a Ti bike frame gets painted, like coil-over springs on car shocks.
True, although springs are often powder coated.
Originally Posted by
chaadster
The reason Ti often goes unpainted is purely for aesthetics, IMO, a way to distinguish and make special the material.
That's probably one reason, but paint can chip more readily on titanium; it requires some kind of etching primer to get paint to adhere well.