General: biopace

I guess you have to ask yourself, are you yourself wanting to change them, cause if you personally want to change them, then go ahead and change them. If your not having any problems, then why change something that is working just fine. That is my opinion.

Sheldon Brown ran them on one of his bikes:

"People are often astonished to learn that I ride Biopace chainrings on fixed-gear bikes. They imagine that there will be tremendous changes in chain tension as the chainring rotates. In practice, this is not the case. A 42 tooth chainring will generally engage 21 teeth against 21 chain rollers, regardless of its shape.
There is a slight variation in tension resulting from the varying angle between the two straight runs of chain as the axis of the chainring rotates, but this has not generally been of a sufficient magnitude to cause any problem in practice for me."

Case closed.

Yeah. My biggest problem with Biopace is that they don't seem to be any different.

I had Biopace rings on my fixed for a while. Had no issues. I only changed it out as I went to a different gear ratio. I'll be putting them back on my geared bike as it gets finished building up.