Originally Posted by
rpenmanparker
The notion that spring constant of the BB has anything to do with the loss or conservation of pedaling energy is at the heart of the question.
Agreed
Originally Posted by
rpenmanparker
Kelly's proposal that measuring that spring constant it will in some way lead to knowing the amount of energy lost or not is absurd.
That's not what I said. The energy stored in the frame is stored as elastic deformation which has two components, the stress and the strain. The integral of stress x strain equals the energy stored (by definition). This is the input energy.
If we make the reasonable assumption that the stress / strain is linear (because we are staying in the elastic region), we can substitute the spring constant measured at the BB and use this to calculate the input energy.
If we then measure the output energy delivered to the drive train when the frame resiles and find that it is the same, the energy lost is zero.
Originally Posted by
rpenmanparker
It is using the hypothesis to prove itself. BS. The idea that Kelly's statement that the energy loss is insignificant answers my initial question is even worse.
I thought the heart of the original question was this:
Originally Posted by
rpenmanparker
I am wondering if there are numbers to support the contention that an appropriately stiffer frame (e.g. at the BB) facilitates power transfer from the rider to the wheels.
Power transfer = power applied - power lost. Power = energy / time.
If the energy lost is close to zero (as is my contention) then the power transfer is the same regardless of the frame. That appears to me to be an answer to your question.
Originally Posted by
rpenmanparker
Who is this pompous fool?
????