[citation][nom]Strider-Hiryu_79[/nom]There is something called gears on a mountain or racing bike. Yah they were invented a long time ago which was designed to handle all types of inclinations and declinations of terrain.Shimano is one of the companies that build them. Yah not impressed.[/citation]
The problem is you need to produce the same amount of power as having the bike on your back and running up a long set of stairs.
I have been cycling 20 miles a day for a while now, through hilly areas.
Using basic Newtonian laws and trigonometry, you can calculate that going up a 15 degree incline uses a similar constant force as accelerating at a rate of 2.5 metres per second per second, enough to accelerate to 30 mph in 10 seconds.
It might not sound like alot, but that is actually extremely tough on long hills, because that's the force you have to produce to simply avoid slowing down to a halt, no matter the gear.
I'm getting better now, but when I started there was a 20 degree hill which i would go at 4mph up in the lowest gear, screaming.
Coming back down on the way back at 36 is fun though.
But I don't see how this has any cost/ practicality benefits over a simple motor and battery in the front wheel, especially since the force is coming from torque on your ankles.