Pete.
The bearings are made by Knott. Only way I can see of making them waterproof is to fit back to back seals.
I did ask about changing them. As far as I remember they are not torqued up like Alko bearings. I got a bit confused by the end of the show.
Too much black stuff and too much info. I am going to talk to Simeon this week, so I shall ask again.
Part of the small print with the bearing waranty is that the trailer is
checked by a dealer each year. As my nearest dealer is Blendworth trailers at Rowlands Castle, I have no problem with that.
BTW Simeon is a Honda Powerboat racer, anyone heard of him?