Led here by a strip of shim found on top of the sump filter. Bearing was installed with Loctite 641 Retaining Compound. I recon I put too much trust in it.
I had the same issue. I used Loctite 620, which is high temp/high strength bonding (this was after it chewed up the shims). The root cause of the bearing spinning was a loose cush-drive nut. That nut has to be tight (65 pounds of torque), because that's what hold the spring stack and spacers together and keeps the inner race of the bearing tight against the crank so it won't spin. If that nut is tight, you shouldn't have a problem. If you're using multiple shims, it's better to keep the thin shims in the middle of the stack. Less chance of them distorting when they are sandwiched by thicker material. I put on 3000 miles since I repaired mine and its still OK.
Draganfly in the U.K. Arrange to have shafts (mainly on Ariel two strokes) ground and industrial hard chromed to restore the correct fit of bearings on shafts. Some years ago I was aware of someone who had a Triumph 650 crankshaft drive shaft bearing area built up with weld and machined to size, the shaft completely sheared away after a number of miles. I believe it was the heat from the welding which compromised this crankshaft and would dissuade anyone from contemplating this type of repair opting for the industrial hard chrome technique instead. Are there any thoughts on this out there?.
I had the same issue. I used Loctite 620, which is high temp/high strength bonding (this was after it chewed up the shims). The root cause of the bearing spinning was a loose cush-drive nut. That nut has to be tight (65 pounds of torque), because that's what hold the spring stack and spacers together and keeps the inner race of the bearing tight against the crank so it won't spin. If that nut is tight, you shouldn't have a problem. If you're using multiple shims, it's better to keep the thin shims in the middle of the stack. Less chance of them distorting when they are sandwiched by thicker material. I put on 3000 miles since I repaired mine and its still OK.
Draganfly in the U.K. Arrange to have shafts (mainly on Ariel two strokes) ground and industrial hard chromed to restore the correct fit of bearings on shafts. Some years ago I was aware of someone who had a Triumph 650 crankshaft drive shaft bearing area built up with weld and machined to size, the shaft completely sheared away after a number of miles. I believe it was the heat from the welding which compromised this crankshaft and would dissuade anyone from contemplating this type of repair opting for the industrial hard chrome technique instead.
Are there any thoughts on this out there?.