resistance bike

Anyone know of a stationary bike that controls RPM’s. That is, no matter what force you put behind it, it will only allow you to move at an RPM that you set. I’d also like it to have a good range of rpm settings available. i have looked, BTW. If you have seen one, let me know where, please.

Don’t worry, found a few isokinetic bikes, both upright and recumbant. Anyone used these/