hi, thanks for such a help full coment its really apritiated. I had not thought about the whole geo thing up untill reading that so thanks again really helpfull. Fo some reason the kid I bought the bike from had kept the frame for years (obv because he liked the strengh) but upgraded everything els apart from the rims which I gess could be pretty old. I have just bought a typhoon frame with +60 BB so I gess without realising I kinda did the right thing and if its a tad lighter than the rex frame then I'm quids in.
edit: I am also in the fairly long process of upgrading parts but thought I would start with the frame. Thanks again man.