Have just replaced the wheel bearings (Al-ko) on my SBS trailer(1600Kg rated) - what a pain.
They are a "sealed" double row taper roller, and have lasted 18 months. To replace the bearings you have to remove the brake drums: 35mm socket and 300Nm of Torque - then ask a friend with a 3.5 ton press to press out the old bearings and press in the new after removing the circlips with circlip pliers. I cannot imagine a worse set-up for roadside repairs!
As the bearings are sealed you cannot easily inspect them prior to failure.
I am considering going to the expense of buying a spare pair of drums and bearings for road use and keeping the old hubs for launching...Though I would still need to fit new hub nuts every time I changed to the road hubs.
Any suggestions, experience with more user friendly hubs?