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.[/i]
Yeah I totally agree with Sheldon on this one as well. The difference in roundness is hardly noticeable anyway. I say again that I have had more egg shaped chainrings from chainrings that were designed to be round!
Originally I wondered what the effect would be of a biopace on a SS and so I jammed the chainring on to investigate it. After installation I measured the chain for tight spots and just couldn’t notice anything bad at all. While the chain tension on this ride isn’t tight, it ain’t spaghetti either. Riding it doesn’t produce that characteristic rattle of a tight spotted chain either. In the end the Missus is happy with it anyway so who am I to change her mind?
wasnt questioning his integrity just using logic… (didnt read the sheldon post before comment…)