I've noticed a strange thing while riding, and need your sage observations on it. Lets say my average speed on flat ground, with no wind, yada yada is X MPH. If I'm riding with someone that is going considerably slower (say X-5 mph) then you would think that I would be able to hold that speed forever.
In practice what I notice is that I'm in such a low gear that my legs get almost burned out from spinning, despite the fact that my cadence stays in the same general range (95 -105 RPM). I'm almost thinking that the fact that I'm getting almost 0 resistance from the pedals on the downstroke my legs don't know what to do. If I gear down so that my cadence drops and I'm getting some feedback on the downstroke then I can ride at the slower speed, but my knees aren't really happy about it.
I guess my question is, why would my legs feel like they are working harder with virtually O resistance than when I've got what I consider my 'Normal' level of feedback while pedaling? )For 10 bonus points, solve for X.)