Thasiet, thanks for getting an answer on that one.

It can be a little messy doing the regular ball bearings. That is the kind of thing I carry gloves for. Basically though, all I do is undo, one side, and unscrew the cone assembly, then I withdraw it far enough that while removingthe bearings they can't fall through. In shop I use a rare earth magnet on a rod to pull them out. Then I whipe up the grease, and pack in new grease, and push the bbs into the grease. If I drop a bb it normally just sits on top of the axle, at the same level as the race so I poke it sideways into the grease. Then I carefully switch sides with the axle, and I repeate the process. Clean up the cones and put everything back in the same place I removed it.

I'm sure you all know how to do this. My point is that with minimal org and process you really can't drop a bearing and it isn't too messy. It's probably a 15 minute thing.

I feel pretty confident that as far as lateral loads are concerned the cone assembly is the one actually designed for it. The balls are large and the raceway is set up to catch lateral loads. The PW with standard cartridge bearings is doubtless wonderful, but if those bearings where going into a machine with significant end loads, they would either be timpken roller bearings, thrust bearings, or some such.

Speaking of loose bearings with rubber shields... I'm no car guy, and can barely change the washer fluid. Yet two summers ago I decided I wanted to do the brake job on the front of my F-150. I had car guy living next door, and got the guide out of the library. The F-150 has the disc rotor integral with the wheel hub, so when you replace the disc you have to do the wheel bearings also and the seals. The bearing assembly isn't a cartridge, but it has all the rollers in a cage. You have to pack them with grease and install them. Pretty familliar process compared to a bike. The bearing asembly on the F-150 takes maybe a teaspoon of grease, scale wise, is about the size of a headset, or somewhat larger. I'm stunned 30 000 miles later it is still going strong. I take from that that bearings are pretty rugged things...