On 2011-05-05, at 3:35 PM, Vik Banerjee wrote:
> The reason no hub can survive dunking is that the seals required to allow that to happen would negatively impact the other 99.9999% of the time you used the hub for "normal" bike riding. It's not a matter of a manufacturer reluctance it's simply a matter of focusing on what really matters to most cyclists most of the time.
I think it is possible to build a dynamo hub that would be not-too-degraded by getting dunked. Technically speaking, the hub is an alternator, not a generator (or a dynamo), and that means that it is just magnets and wire -- no brushes, no parts touching except the bearings. You would want everything coating the electronics to be water-repellent, so that corrosion is minimized.
After that, it's just the bearings. If you can repack them after the dunk (not possible on both sides of the Shimano hub, at least as far as I can tell), then you can recover. Reassembly can be a little tricky if you pull the coil (and ferrite) out of the magnets.
What did in the S12, is that there's some electronics in the butt of the device, that control some aspect of its operation, and they did not recover from getting wet.
Not knowing what is inside the SON (it could have similar electronics, and that would be consistent with its high performance) it could indeed be more vulnerable to the wet than the Shimano, which is clearly "just an alternator".