I have a few bikes (road, hybrid) as well as a Keiser Mi3 spin bike. For some reason the Keiser always seems so much more difficult in “feel”. It feels heavier and my legs are left tired from a session on it.
I decided to do an experiment. To eliminate the power meter I used the exact same calibrated power pedals. I also triple checked the fit was the same measurements. Heck I even have the same seat. Both rides were continuous pedaling steady state rides (I biked up a steep hill to completely eliminate gliding). Same wattage. Harder on the spin.
Obviously they are different bikes (between a light road bike and a weighted flywheel), but it’s the same power output at a continuous pedal exact same power meter and crank length.
So I became curious why at the exact same power can a ride feel so much more difficult on the spin bike. Then it occurred to me that there is no side to side motion on a stationary fix spin bike therefore no upper body transferring of energy.
So that raises a different question…am I better off with the static (Spin bike) for more of the training or the dynamic (Road bike). If you only could pick one which would you chose and why? Should I be adjusting up or down for each bike?
To me a watt isn’t just a watt in that you’re using more of your body on a road bike to generate it where as spin isolates the legs more. To illustrate this to the extreme imagine 200 watts on a road bike vs 200 watts on a recombinant bike…different muscles different exercise really. Not as extreme in my case but still some what a different work out.