Many current designs are now using an integrated bottom bracket with outboard bearings. This is an attempt to address several issues associated with weight and stiffness. Because of the relatively small 1.37" (36 mm for shells threaded to the Italian standard) diameter shell, designs that place the bearings inside the shell can either have large bearings and a thinner spindle, which lacks stiffness, or smaller bearings and a thicker spindle (such as the original Shimano Octalink), which lacks durability. External bearings allow for a large diameter (hence stiff) and hollow (hence light) spindle. They also offer more distance between the two bearing surfaces, which contributes to stiffness while allowing lighter components. A different approach would be to standardize on the larger BMX shell for all bicycles, or the BB30 standard originally introduced by Cannondale.