When I learnt to build wheels on Edinburgh Bicycle Co-op's course, I was told to build radial spokes with the elbows outside (or heads in) as that would make for a stronger wheel. However, I noticed that factory built wheels always had the elbows inside. I eventually managed to speak to a wheel builder who told me the reason was that with the elbows out, the wheel is indeed stronger but as a result, it puts extra stress on the hub flange and the manufacturers won't guarantee it if it breaks. So I rebuilt the wheel with the elbows in.
When I learnt to build wheels on Edinburgh Bicycle Co-op's course, I was told to build radial spokes with the elbows outside (or heads in) as that would make for a stronger wheel. However, I noticed that factory built wheels always had the elbows inside. I eventually managed to speak to a wheel builder who told me the reason was that with the elbows out, the wheel is indeed stronger but as a result, it puts extra stress on the hub flange and the manufacturers won't guarantee it if it breaks. So I rebuilt the wheel with the elbows in.