Originally Posted by
Scooper
Curious about the question of measuring STA and HTA relative to the top tube and assuming the top tube is exactly parallel to a line through the front and rear dropouts, I measured the angles of my 2007 Waterford RS-22. From all appearances the top tube is level and there is nothing on the factory geometry drawing to indicate a slope.
In fact, the top tube has a 0.7° slope down from the head tube to the seat tube.
In that case either the factory drawing geometry is wrong (unlikely) or a combination of tolerance stack, geometry variations due to frame size differences (geometry varies slightly in sizes other than on the official drawing) and finally measurement accuracy all contributed to your 0.7° measurement. I would still consider that a horizontal top tube even if it was possibly built or measured slightly different from what was intended.