Better (more expensive) Engineering. Different frame geometries, different materials, better quality control on the welding. One of the main reasons for the recall was that babboe did not follow up on reports of frames breaking until a regulator stepped in. And by then, it was too late to contain it to a few batches.
Babboe is a rather budget brand that uses a single round lower tube under the box. Compare that with the frame of an urban arrow or a R&M load that use multiple tubes and a proper stiff platform under the box. Even if an Urban Arrow Frame would crack, it would bend out of shape instead of failing catastrophically like the Babboe did.
Maybe a better alloy? The urban arrow also has an aluminum frame though, which is the normal recipe for snapped frames. Having broken a couple myself, and not being a racer, I always opt for steel now.
