My in-laws were nice enough to give me their old DP Fit for Life Air Gometer stationary bike. It is an air resistance bike, and the handles move back and forth and you petal. It's pretty old, but it's in good shape. They didn't have a manual for it. The problem is, I can't figure out how (or even, if) the tension can be adjusted. I'm not in great shape, and the times I've tried to use it, I feel like I'm pedaling a bike up hill, carrying a load of bricks. The only knob I can find on the thing adjusts the height of the seat. As it is, I can barely use the thing without running out of breath in five minutes. I need to set the tension to be lighter, so I can work up gradually. I've searched all over the web, but I can't find a web site for DP Fit for Life equipment, or anything else that helps. I'm hoping someone here might know something and be able to help me.