Well, if you insist on making more out of this than there is.... The wheel felt fine without the spacer and it looked pretty normal unless you knew exactly what you were looking for (which I do now, live and learn). The guy who was working on the bike is a pretty knowledgeable mechanic I actually talked to him about some other things while he was working on the bike. I always check the chain tension before riding and I also grab the wheel with two hands and yank it side to side. When I got the bike from the dealer I didn't check this, as they have been pretty good about their workmenship. If you leave the spacer off the wheel feels pretty normal until the bearings go, then you can definitely feel something. I did hear some grinding as I got home, but I wrongly figured it was the lose chain touching my hugger.
As I was rolling down the highway at 70 mph, I heard the grinding first, this was undoubtedly the bearing actually breaking. As I limped along at 20-30 mph, it obviously gave way completely and that's when the bike pitched sideways. If this happened at speed I think you would have some warning as the bearing started to fail. It would give you a few seconds to get the bike slowed down before all hell broke loose. But you would have to be paying close attention as the initial problems are pretty subtle.
I do alot of work on the bike myself, almost all of it. I don't do tires, and don't really want to. I like to take the bike in occasionally as I am not a certified mechanic either and there have been things this dealer caught that I didn't. For example, my front brake lines look fine but when they extended the forks completely (like in a wheelie) they noticed the lines were being stretched, so I'm getting +1 lines. Apparently the new forks extend further than the stock ones did (I actually checked this before when I installed the lines with stock forks as the front wheel was suspended). But hind-sight is 20/20. Who would check wheel bearings. there isn't even an interval for this in the maintenance routine. If you checked everything on the bike you would never ride it. However my big failing was when I heard grinding the first time when I was getting home from the dealer I should have chased the source down no matter how much of the bike I had to tear apart. The attached shows the spacer that was missing. This should have been obvious to me from visual inspection as I have had the rear tire off many times. So, this is a warning to me and now I've shared it with you all. Next tire change you might want to look at the bearings and make sure all is well. Also, always grab the wheel and yank it side to side as a part of your pre-ride check.
