Not sure on which forum I read this, but the layup of the De Rosa is much different. Also, the way they build the frames is different in that the
Ribble using some balloon thing when building, which isnt as good as whatever layup method the De Rosa uses.
Whether you can feel the difference only you can tell. I suspect a better wheelset may make a bigger difference.
here is the more exact write up
Cheaper frames have more resin in than more costly ones, hence the tarmac at £1300 even though its an SL4 frame is heavier than the Tarmac sl4 at £3000 frame. They are made by having a bag inside that when the frame is formed he bag is removed, to do this there is a sacrificial layer on the inside that gets shagged when bag is removed so individual frames can have slight weight discrepancy. The McLaren tarmac uses a very special frame production that does not need the sacrificial layer so lighter and more consistent weight. The De Rosa costs more as it has less resin and a more complex carbon lay up. But you have a budget and wheels are an important element of any bike, I personally would have gone for the tarmac used the wheels that are on it as unimpressive as they are then chose some nice ones to save for.
