Originally Posted by
SharpCdn
By looking at the pics below, you may notice that there may have been an advance warning sign that went unnoticed. There is a darker area along the fracture where the fracture has oxidized. I think this must have been an existing crack in the handlebars that went unnoticed.
my interpretation is that the darker area is the rupture zone, i.e. the part that failed last. I don't really see the typical weathered area on the crack surface that you often see on fatigue surfaces in bike components.