Not a Pedal gen.
Take the concept 2 rower. It already spins a flywheel, that is to generate resistance for the puller.
What if that flywheel mechanism can be connected to a gear box. A gearbox with various assortment of gears. The different combination increasing the resistance being pulled.
The platform of the rower being modified, so in a vertical position one can do movements ranging from a face pull/tricep push down, to a bicep curl and rear delt extension. Under the rower platform a base plate with quick connect straps for deadlift and other ground lift movements. In the horizontal position, a longer/convertible seat, for rowing, that can be pinned in place for bench press, that can sit up on an angle for traditional dumbbell movements, and perhaps a high position foot plate for leg press.
The gear box connects to an alternator/generator.
It's setting up a gearbox to replace weight selection that I'm having difficulty with. The Tonel with a simple winding mechanism changes tension between 5-200 lbs.
How can one increase the tension in stages between 5-400+ lbs, while taking advantage of the additional force generated as electrical output.