George, Actually, Vitus 181 is the same material composition as SV 980 in a heavier form. It's1.0mm X .07mm main triangle, the chain stays are .9mm, the seat stays .8mm. Reynold's would add a letter to the material code to signify weight and tube length class, for example, 531C or 753B. Vitus had a more unified carbon grain distribution than 531 and also a higher elongation pertcentage which probably gives it the supple ride characteristic;or perhaps it's the frame builder that does that, at least that's what I'd like to believe, but I'm probably wrong. Bye for now. Anthony Mezzatesta
Anthony
Many thanks for the info on Super Vitus -- I was looking at a site that
compares a variety of tube material to one another. I was a bit surprised to
see several different grades of 531. However the SV 980 looked to be
lightest. Vitus 181 was a different beast altogether. Oh well... thanks
again for the info.
george