Would be good to catch up with some MTB mates from long ago. Do we do that on this forum?
Whoa! slow down and pour a cuppa.
All machines convert energy but the process is never perfect. However, the bicycle takes the innefficient, semi-evolved human body and uses it's power to produce speed and endurance that is fluid and impact free. Our mental capacity invented a way to improve our physical capacity on a scale that had never been achieved before or since. That is why the bicycle is the ultimate machine. Without us it has no function or purpose. With us it is greater that the sum of it's parts and, with it, so to are we.