Originally Posted by ericm979

Power Transfer is a myth, dreampt up by marketing. In almost all cases it's BS. (If someone wants to argue this, please find me a study that shows a significant power loss due to flex. I haven't found one yet. Also, Sean Kelley Vitus 979 etc). A flexy frame (or any other part) doesn't make you slower, because it's a spring. When it flexes it flexes back, returning whatever energy it took to flex it. However a rider may prefer the feel of one vs the other. You'd think that a perfectly flexless frame would be best but it's not. Besides the jarring ride, you need some flex in the frame for traction. For example, when accellerating over rough pavement. If the frame flexes a little the rear tire won't skip as much. But basically it comes to rider preference.