You asked about four spoke wheels. Yes they do exist and they are made of 
carbon. Though the wheels have less spokes, these wheels are not necessarily 
lighter and in most cases heavier.
Tubular tires are known to make wheels lighter then those with tubes. 
Magazines have been known to support tubular tires stating they give better 
handling and can never have a pinched tube. I weighted my tubular wheels and 
they are lighter then my regular ones.
Richard G
--- Maximus/2 3.01
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