I read all the threads regarding disc wheel covers, and the consensus appears to be that aero trumps weight. However, the importance of aerodynamics increases with speed, while weight is independent. What’s the minimum speed at which the aero advantage of a cover begins to outweigh the extra 500 grams it packs on? My long rides are between 16 and 17 mph, so I’m not super fast to begin with. Should I bother with a cover?