Quote:
Originally Posted by mtechnica
If the chain stay is a fixed length and the bottom bracket shell moves left and right, wouldn’t that mean that the distance between it and the hub actually increases under load since it would be the hypotenuse of the triangle it would make? The distance can never be less than in the unoaded state correct? So long as the chain stay isn’t under compression.
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It is already a hypotenuse because it angles from the outboard dropout to the inboard BB shell. When you push the BB over you are making that base leg longer, tugging on the hypotenuse.
Quote:
Originally Posted by mtechnica
At any rate shouldn’t energy loss be accountable with a hub based power meter?
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There doesn't appear to be any energy lost when it has been measured with power meters. Some cyclists disagree with that, but everyone who has tested it in a lab all agree that frame flex doesn't eat energy.
Quote:
Originally Posted by mtechnica
The whole point of a bow is that it stores energy that is applied slowly and releases it again quickly, is that what we’re saying is happening in the frames system? If so what is the energy that’s being released acting upon?
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Since the frame has two crankarms and the BB can flex either way in a bow-like manner, it is more complicated than a bow. But the flex is essentially forced to zero out between right and left pedal stroke.