Bugga, Damn, Feck and Blast
Because working from home and on US timezones can sometimes be a wonderful thing, I got around to changing my rear wheel bearings this morning.
I've done this job once before without too much hassle, although the design of the brembo rear wheel and the fact that there's a spacer with sort of star pattern ribs along it to hold it in the middle between the two bearings means that you can't get any purchase behind either bearing to tap them out.
So the only way that I can see to do it is to break one of the bearings out with a hammer and cold chisel. Did it last time with only a couple of minute scuffs on the wheel boss.
Got to choose one side to start, so I chose the disc side.
Today, I positioned the cold chisel carefully on the outer race of the bearing and gave it a bit of a thump. Cracked through the case hardening pretty easily in one spot and got a 1/2 cm chunk of the outer race out, so all I had to do was choose another point to crack out and the rest of the bearing would just come out.
Positioned the chisel carefully again and gave it another crack. This time I had managed to hit the chisel a glancing blow and it span round in my hand, whacked my thumb (with the inevitable skinned knuckle), but at least it had cracked out a big enough segment of the outer race so that I could brush the bearing surface clean.
But....disaster...the spinning chisel had cracked the race all right, but it had also put a gouge into the bearing surface of the wheel. Looked at it more closely and there is also a hairline crack about 3mm deep running right across one edge of the boss.
What the hell do I do now? I don't fancy the thought that the wheel bearing boss has got a stress crack spreading when I'm cranking the bike into bends. The only thing I can think of is getting it welded up and machined.
I'm not normally so cack handed
[Edited on 21-3-2005 by Jools]