Something I've been wondering for a while. Are hollow kingpins/axles stronger or weaker than solid ones? Think I read somewhere (probably here) that hollow kingpins are stronger because they can be heat treated on both sides. But my intuition tells me solid would be stronger because more metal. Does anybody know the answer for sure?
Hollow are definitely harder metal, especially catching a hollow kingpin on any edge, it gouges it, where as regular kingpin no where near as much.
As to stronger, it could be said yes, but I have still seen hollow axles bend, sometimes faster than regular axles, so I tend to be happier with solid / standard axles and kingpins on my setups.
For weight though, sure they are lighter, which is why they would be more popular for a lot of people, with other things as mentioned above less likely to affect their decision on product choice.