This looks so inefficient. I feel they might expend more energy getting the legs moving rather than moving.
Most likely, but it could definitely be made. Getting it to rival a bike would be the trick.
Since it's a walking mech, the implication would be that the locomotion would be done by an on-board computer, and the bike handles only serve as a steering wheel. Perhaps then, the pedals are only to supply power.
Dynamo bikes have existed for a while, so maybe they have some kind of efficient new model, but I'm not sure how much juice you get per minute of pedaling on one of those. My guess is that the robotics on the mech would take up too much power to move any faster than a stroll. You would have to have some kind of high-grade conducting wires and a powerful generator to get enough juice to move the thing faster than a person on foot.
There would also need to be some fine programming on those robotics to balance the mech, the rider, and a dynamic input on the legs to ensure it drives reliably.
could you use a flywheel and directly store mechanical energy instead of converting it into and back out of electricity
That'd be another way to do it. Kind of like a wind-up toy, if I'm following your idea right, the pedaling would crank a gear that loads mechanical energy into the leg parts, which would produce mechanical motion without the use of robotics or electricity.
There would still need to be all the balancing and movement fidelity stuff that would need the help of computers though. I don't think you can make something like this that is purely mechanical with no electricity or robotics and have it be reliable enough to handle dynamic inputs and varying terrains.
maybe there could be some kind of hybrid system, where the legs are powered by mechanical gears and balanced with battery-powered servomotors on key joints while the whole thing is monitored using a micro computer that tracks the reports from the servomotors and makes adjustments to the system.
I have no idea if that something could even be made to work that way though, and I'm not sure how much speed you would get out of the system.
It would probably be easiest to build an electrically powered mech where the pedals were only the input controlling how fast to go forward or back, and to provide the user with some psychological and physical benefit to riding.
If we're talking about whether you could build such a thing in the near future, I think you could do it like that.
The benefit for this over wheels would be the ability for this to move over different terrain.
"Rule of Cool" aside, this reminds me of Big Dog (the horrifying Boston Dynamics robot), and the point of that design is to be able to follow solders who are on foot through thick jungle, rocky terrain, or anything inbetween.
The legs (on the bothe car and the bikes) do provide an advantage if they live in a mountainy area or some sort that isn't all flat. Even if it does look rather suburban here. Also, I suspect those bike things could jump, which would be rather handy.
I'd like to imagine one of the more interesting experiments to try would be stairs on the road. Instead of building a road going up a steep hill, cars and motor-bipeds would go up stairs leading around and over. On and off ramps of the highway could be stairs too, and city roads could connect in interesting new ways with stairs leading up and down to different areas. It would also eliminate a lot of the hassle of building on sloped terrain; just dig out and plop down your ISO standardized prefab car stairs and keep going.