Originally Posted by Carbonfiberboy

The weird looking fluid you found in there doesn't sound right to me. It should be clear or nearly so. I've used a fluid resistance unit on my rollers for 25 years. Something went wrong with the original fluid in it - it got too easy, like the viscosity had gone way, way down. I drained out the old stuff and replaced it with silicone oil treadmill lubricant. That was about 15 years ago and the resistance has stayed consistent over the years. That oil is easy to find online.

I ride my rollers more than I ride outside, several hours a week. IME nothing really happens fitness-wise until I've been riding for 45'. That's when the good stuff starts. Also the leg pain if you're not used to it, but that's just part of the "good stuff."