Multilink suspension can have axle paths that would be impossible with a single pivot (most of them don`t, or are not far off a single pivot arc) and has nothing to do with breaking the 2nd law of thermal dynamics. And if you say a chain stay pivot isolates forces would`nt it then isolate the force you apply to the crank and fail to drive the rear wheel or is it like a diode and only works in one direction
Ah, your one of those types. You learn a few big words in your 1st year physics class and like to regurgitate them without really knowing how or when they should be applied.
Perpetual motion has nothing to do with bicycle suspension. FAIL. I look forward to the day that my bike can power itself without an engine or a self powering one but honestly I don't see it happening.
ANYWAY............The fact that most may not be 'far off' a single pivot arc means that their path is indeed modified. On a bike very slight differences can have massive effects on the characteristics of the ride. As an example, you wouldn't think that 1 degree difference in a head angle would change much but it does.
The proof is in the pudding as they say, if you think a single pivot rides like a Horst Link then you should get out and ride a little more. Too much time in the lab makes for a dull and experience lacking nerd.
Oh, and don't take things too literally. Im not saying the rear end of a four bar is completely isolated from all forces but it does a much better job of it that a single pivot.
Really sorry to the rest of you for turning this thread about a pretty cool bike into a dull physics debate.
There goes the bell Brute, class resumes never.