Quote Originally Posted by gwernaffield View Post
it does not matter how smooth the bearing ball or how round , until Michell sort the main problem , the smoothness of the components that make up the bearing it self , with the top of the bearing looking as thought it was done on a hand grinder and not a mirror finish , and the cone has the same problem , if you can feel the top of the bearing shaft with you finger it is too rough , the bering having to bed in which takes a long long long time, the ball sitting in the cone that is like tram line finish cannot sit properly ,
Nothing is perfect Pete, but it does make sense to me to put in the roundest possible ball to ensure that any platter "rocking" would be reduced in the cone area as much as possible, as well as one that could also reduce friction & further vibration at the top of the bearing shaft, regardless of any limitations in the stock bearing. Or, as they say, two wrongs don't make a right.

I've been using silicon nitride balls now for more than 3 years with excellent results. It makes no sense to me that they should be more prone to cracking than any of the other non-steel balls-there's a reasonably strong argument that they should be less so. Personally, I feel that
the purported problems with micro-cracking are a bit of an urban legend going back to when John Michell was alive and ball bearing technology was
a bit more primitive and there may have been some problems. But that was a long time ago.

I believe a number of very high end table manufacturers are also currently using silicon nitride balls in their bearings and can't see them doing so
if there were serious problems with the balls.

In any event, it is cheap to simply pop in a new ball every time you do any oil change, which I think is a good thing every few years.

I could never go back to a steel ball, any more than I could never go back to the springs now either

The silicon nitride ball will, in my experience, sound significantly better than the steel ball right out of the box and it will take probably 30-45 days
to bed in (possibly less with a lot of use), at which point it will be even better. Anecdotally, I felt that the last time I did an oil change and changed the ball there was very little change in the sound of my table. Prior to that whenever I rotated a steel ball or changed it I felt that the new ball had to bed
in entirely all over again and that the sound from the table was a bit edgy/strident for a few weeks.

Proof is in the listening as they say and it's $5 and easily and instantly reversible.