If you add more resistance to the rollers you could replicate but it wouldn’t be identical.
But it is identical, it has to be
Some numbers (as I’m sitting waiting for a delivery)
Imagine you are 80kg (with bike), travelling up a 10deg hill at 10km/hr (at least thats as fast as I can manage 🙂 )
Your speed in m/s is 2.78m/s
Your height increase per second is 0.48 m/s
So your increase in potential energy per second is 378 J/s – roughly what you would expect
Ok, on the rollers set at 10deg
Force straight down due to gravity is 9.8N/kg
Force pulling you back on the rollers is 136N (remember you are 80kg)
Now you need to produce that same force on your wheels to stay at the same point and not slip back
Work done per second = F * distance traveled by wheel in one second
= 136 * 2.77
= 378 J
The problem of course is whether or not you believe the wheel does any work by rotating rather than moving forwards – but my legs say that it does and I believe them