[PMGRACER]

Been a while since I've been in the Bicycle bus, but 15 years ago Kestrel made a Monocoque style Carbon Fiber Frame. They in fact did use a bladder and foam. That manufacturing method didn't produce a reliable wall thickness as the resin would not flow evenly. That is why Trek originally developed the OCLV design which had the reinforced lugs. I think currently Trek still uses that style of Manufacture but the Head tube, seat stay/ bottom bracket and chainstays are moled as one piece units and straight tubes are bonded to them.