Integrated oversize BB
The downtube flares at the oversized bottom bracket junction, achieving several design goals. This construction adds lateral stiffness without increasing wall thickness, and the new bottom bracket mold disperses loads to effectively halve the stress on this crucial junction. The shape of the downtube and bottom bracket carries seamlessly into the chain stays, further reducing turbulence and creating an additional aerodynamic benefit. Also, the drive-side outer diameter of the bottom bracket conveniently accommodates an SRM or power meter.