if you goto ebay, and search for carbon frames, a bunch of generic looking, non-decaled carbon fiber hardtail frames popup from chinese (usually HK) sellers. some of them state that they are OEM carbon frame manufacturers, and use 100% carbon fiber...blah blah blah. i'm planning on building a cheapo xc hardtail to ride around pretty smooth/nontech offroad trails. has anyone gotten one of these? if so, how was the construction? durable?