SJX426 

Good question! I don't recall any instruction in my mechanical engineering education of how to design cup and cone bearings of the configuration used on bicycle hubs. I may not have signed up for that course or they didn't think it was important given it is a commodity design!


My suspicion is that the radii of the cup and cone are slightly larger than the bearing radius. this approach would allow for a point contact between the two surfaces. This may seam counter intuitive at first but if you think of the slight variations of the manufacturing process including tool wear, maybe not. So then you might think that a point contact would have incredible forces applied until you realize the hardness of the material, not to mention the number of balls that might be used in the assembly. More balls, greater distribution of force. Now, now, stay focused on the subject!


Most of the stuff we see, as the forum title might suggest, is worn surfaces that reflect either the contact patch path, or the area of the track of the ball during use. Don't know which or if it represents both.


If there is a ME being a bearing design SME on this forum? I would love to know the truth! How much if any of the race radii is the same as the ball radius? If it is not the same, is it a uniform radii or more parabola like? Of course you must answer the question of why the design is what it is!