remember these...

biopace...
Originally uploaded by divine_gear

it's the old biopace chainrings. for those of you who do not (for you are too young to), the rings are not circular, but rather an oval shape. why oval?

because in all circular chainrings there are two dead spots where power is lost. the twelve o'clock position, and the six o'clock position. this is just the nature of a circle. and because of these 'dead spots', power is lost, you are in a sense not 'actually' putting power into your stroke.

the oval shape eliminates that. there are no dead spots in an oval shape chainring.

now why didn't these catch on? well...pour shifting is the only answer that i have found.

i did have a chance to take these for a little ride around the neighborhood, and i've got to say, it's a shame that they don't make these rings anymore. they felt incredible. smooth. fast. really nice. they had to come off of this crank, because some teeth are worn, unfortunately. if i could have, i would have kept them on.

now; bobby julich's bike of team csc does ride something similar to the oval. he rides o'symmetric chainrings on his road bike for the very same reasons stated above.

i'm sure with computers the way they are today, somebody is able to come up with a better design than the old biopace. any mechanic engineers what something to do in your spare time?

amitabha...