Indeed. I assume this confirms my hypothesis that they simply machined the outer ring to meet their specifications. I can’t imagine how else they’d reach those dimensions while holding ball size constant.

EDIT: They may also have “shaved” material off both the inner race and outer race, which is a much better, and much more expensive solution. However, my point still stands.

This seems consistent with what this industry does when a square block meets a round hole. Or more specifically, when a large OD bearing meets a small OD shell. People try to fit the same 6806 30mmx42mm bearings into 41mm holes for BB86. BBInfinite also makes a BB86 BB for 30mm spindles, which I assume uses a similar strategy.

The following is a novice speculating based on crude internet research: The reason why machining the outer race down causes balls to get crushed is because there is a minimum amount of “retention force” required to keep the bearings from popping out of the aluminum sleeve that BBInfinite makes. This retention force is proportional to the stiffness of the shell, the stiffness of the bearing and the amount of interference between the two. If the stiffness of the bearings goes down, then the interference must increase (slightly) to achieve the same retention force. Also, when you put your body weight on one of these machined bearings, the ball at the bottom will get crushed a lot harder relative to the others in the bearing. This is magnified when the outer race loses stiffness.

However, the biggest reasons for bearings getting shot are misalignment and contamination. Contamination is unaffected by this approach and misalignment is reduced. Like I said, pick your poison.