What is this ????

Yes, this is a rim brake CX frame but in the WCCX format with the flattened top tube and seat stay gussett. This is the only one I have built so far and I'm not sure if there will be much of a demand for more of these now that disc brakes have really become the norm in CX. 

That said, it is cool to have built one in 2023 and I'll hopefully get some photos of the whole bike from the customer when it is built. It is light but not too light , having two of my NOS Easton USA main tubes to stiffen up the front triangle. This rider is not heavy but here pretty tall and can put some serious torque into a bike. I hope that this bike delivers the stiffness he is after.