Litespeed Siena 51.5, small anyway.

I don’t know in all honesty, googling titanium frame fail and it's always at the welds. eBay sucked I thought I’d come here and take a drubbing on price but hopefully with some like minded souls, its a lovely bike end of, the ding was of no consequence when I bought the thing (read on), and if I had the room and the finances, frankly I’d keep it as it handles so well, and hadn't considered a career in dirt jumping on it lol. Still for sale though. As I need the room. The underneath of the tube is a V shaped spine, the tube itself is a graduated box section like a radiused parallelogram and about 50mm wide at that point, and 40mm deep. from my limited knowledge of physics, apart from being inherently strong the stress on that tube would be dissipated to the spines on the sides rather than the top.