gizzo wrote on 05/08/17 at 01:25:40:I like that idea. My ski boat trailer has something similar called a Bearing buddy. You just whack them onto the hub and pump the grease in. Works well. For the bike, why would you bother? Replacement sealed bearings are so cheap and last almost forever anyway, the originals wouldn't be worth bothering to repack.
I learned the purpose of the bearing buddy is to keep internal pressure on the wheel hub, and keep water out (as well as provide a way to grease the bearings). Evidently the problem with boat trailer bearings is that you run down the road on a 90 degree day and get the wheel hub warm - then when you launch your boat you submerge the trailer in 60 degree water.....and the air inside the hub cools and contracts and pulls the water into the hub. The Bearing Buddy has a spring that keeps a small amount of positive pressure inside the hub so the water isn't pulled inside.