I have an old Tuntori stationary bike. It has the large, heavy flywheel and adjustable resistance using large brake pads. All pre-electronics, too. (Even has a mechanical timer, LOL.) I got it while I was rehabbing a busted knee. You can find these used. There's one on my local Craigslist now for $75. These were high quality and don't have a lot of slack in the pedals like some cheap exercise bikes which can be hard on the knees. It's an upright position.