Dave Kirk was responsible for the DKS rear when he was at Serotta.......He also had input in to the ST rear. Both were designed to keep the rear planted on the road especially on bumps and cracks. He designed the Terraplane to accomplish the same thing. As he says on his site:Kram59 said:Hey Len. Just curious. What advantage, if any, are those curved seat stays supposed to deliver, other than looking real cool and sexy? Great bike, again.