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New school question(5 posts)

New school questionJohnIV
Jul 1, 2002 12:24 PM
I just started riding 2 years ago. I was wondering if someone could explain what Biopace cranks were. A picture would be great too. I was just curious as to what these things were, and why they were such a flop. thanks
Old SchoolVeloGal
Jul 1, 2002 12:37 PM
I am not sure they were such a flop. I still have a pair or two going around. I think manufacturers feel the need to reinvent the wheel and come up with ideas such as biopace.

Instead of using cranks whose rings were circular, biopace used an oblong shape - not an quite and egg shape nor ellipse but somewhere in between. The idea was that the powerstroke was not constant throughout - that is, there was a certain part of the crank where spinning would be easier.

Try a google search and I am sure you will find an image.
Old School Pt IIRavik
Jul 1, 2002 12:43 PM
It also had to do with the reawakening of biking in America -- manufacturers tried to take advantage of the firsst wave of new riders in years and believed that a throng of new riders wouldn't be able to efficiently spin or pedal in circles.So, viola, the biopace.
Its predecesor was, I think, the power-cam, or something like that, very funky.
Here is a pic. I'll let the engineers explain...Dave Hickey
Jul 1, 2002 12:44 PM
Notice the rings are oval and not round.
A short explanationbrider
Jul 1, 2002 2:15 PM
The idea was to decrease the lever arm of the chainline during the deadest parts of the pedal stroke. Good if you're a masher, bad if you're a spinner.