ally frame...top,down,seat tubes externally butted andgo round to diamond profile at ends...seat stays elliptical to round at dropouts..seat /chain stays welds filed and scalloped at dropouts..originally xt 7 sp..frame weighs 3 3/4 lbs,fork 1 3/4 lbs..seat tube 31.6 mm.,horizontal top tube..hopefully pic posted..cheers.