We take air-operation into consideration seriously when we design this bicycle and you will have a nice acme experience when you are riding it. The back rim of its down tube is flush just like the shape of plane wings and the back ends of its seat post is arc- shaped,which will wrap the back wheel and reduce disturbing air current.Its seat post is flat-shaped and use hidden post clamp.The joint of its thin seat stay and seat post is low and to reduce the air-operation at the same time, it’s stil...