I don't understand this chart. The flywheel of the trainer is turned by your rear wheel. Your rear wheel turns at a speed based on cadence and gearing. Turning a 53x12 at a cadence of 60 turns the flywheel at the same speed roughly as turning a 39x15 at a cadence of 100. But the wattage charts shows 700W vs. 500W.

What am I missing?