John B. -

seat post angles forward of the BB...this allows upper torso leaning forward, thighs backward down to the BB...linear...for running forward on pedals

post backward over BB allows maneuverability around tree stumps with weight on back wheel...maneuver over power. Tho you can stand up n power.

I'll bet EXRX knows if arms are up or down when sitting for abdominal power to thighs.