Biopace chainrings ?

[gbb]

Do they wear unevenly ?
I aquired a triple setup crank....not because i want Biopace, but just got an old MTB i could fit them to...anyway i digress....

The chainring teeth have worn noticeably at the peak of the ellipse if that makes sense...but still look good over 75% of the rest of the rings.

Anyone seen that ?

I think they're good enough for the job i've got lined up...just bugged me the wear pattern.

 

[PpPete]

This might explain why....but I'm not sure.

 

[mickle]

All rings wear unevenly.

 

[gbb]

Funny thing today...another car boot, another MTB crankset (Exage) with Biopace chainrings...better condition, but same 'wear' at the 'top' of the ellipse

 

[mickle]

Yup, coz the top of the ellipse is the sector of chainring which transmits the greatest load to the chain through the power stroke. Same as a round ring.

 

[gbb]

Yup, coz the top of the ellipse is the sector of chainring which transmits the greatest load to the chain through the power stroke. Same as a round ring.

I had to think about that !! Of course it makes sense. i guess i've never studied the different areas of a round chainring in detail.
Makes sense when you think about it.
Problem solved...muchos obligardos