| Author | Message | ||
     Mark_weiss |
Stopped at the roadside, I happened to notice a couple of small grease trails emanating from the drive side of the rear hub. Closer inspection revealed minimal grease and an odd black thread. Pulling the thread loose, I noticed that it felt rubbery. With a few hundred miles yet to go, I stopped a few times to inspect the bearing area and found no further issues. Stopped for the night, I thoroughly wiped the area clear and saw nothing worrying. After Sunday's ride home I removed the rear wheel to get a really good look. After wiping the bearing really clean I noticed something odd. On one side of the bearing, I could see deeper along the inner race. It turned out that the mysterious "black rubber thread" had actually been the inner edge of the bearing seal's inner lip. The part that would seal against the inner race. What I was seeing, was the inner part of the bearing. If I had washed the bike or ridden in rain, water could have easily gotten into the bearing itself. I wonder how many premature wheel bearing failures may have been not from bearing load, but from seal failure. Without removing the wheel and carefully wiping the bearing clean, there was no way that this problem would have been noticed. The bearing in question was a black seal KBC, supplied by Buell. (Message edited by Mark_weiss on June 26, 2012) | ||
| Mark_weiss |
If you look closely, you can see that the edge of the seal is missing on the right side of the inner race.  | ||
| Mnrider |
Looks like you caught it in time. I replaced my notchy bearings at 10k. | ||
| Natexlh1000 |
Weird one! Most failures seem to involve water getting in. |
