Originally Posted by
Andrew R Stewart
Francis- I don't doubt the goals in perfect worlds but we both know that bike manufacturing has been less then perfect since it's beginnings. This too, is why i like angular contact bearings. However when i feel a radial contact cartridge in the shell after I've removed the axle, rotating the inner race with my finger and feel roughness. Then remove the bearing and feel no roughness what am i to deduce? With the axle removed I often can feel the slight end play between the outer and inner races yet still feel grittiness. In my understanding this is a roughened bearing surface. When, as I say, the installation preload is gone (the bearing is out of the shell) this roughness reduces or is gone. Am I missing something? Andy.
It might be a tolerance issue. I'm insulated from this because I only see high quality bearings from folks like skf. These are extremely consistent bearing to bearing, so if installation compression were an issue, it would be an issue on just about every bearing. OTOH, there are plenty of not as good bearings out there.
My friend at skf goes through constant loss of customers to China because of price, followed by the return of those same customers, when they suffer poor bearing life. In most applications bearing life trumps everything because the cost of replacement, including labor and downtime dwarf the actual cost of the bearing so companies with solid reputations can maintain market share despite lower priced competitors.
This applies less in the bicycle world since the people spec.ing bearings aren't the ones paying for the replacement.