I know there's others... Seriously... Especially with the TP... What's the point in having a top-tube seperated from the downtube? And even chainstays seperated from the "seat"stays. I know Koxx tried one - but I haven't heard anything about that for a long time.... The TP is the prime example, really. They're as good as one tube anyway. Just make the frame a Y-shape... with a kink in it where the stays join the downtube - save having that drop-down bit that Koxx effort had. Is it all to do with pressures, or something? I don't know much about different metals etc - so forgive me that... but still.... If the TP can get away with that much.... why not?