Originally Posted by Carbonfiberboy

Everything said above is true and to the point. I would add that differences can be explained by this simple rule: cadence and force at any particular speed will move in opposite directions. IOW increasing cadence decreases force and vice versa. There is an aerobic cost to pedaling faster and a muscular cost to exerting more force. Thus if you are breathing hard but your legs aren't feeling it, you should pedal more slowly in a higher gear. If your legs are hurting but you could be breathing harder, you should pedal faster in a lower gear. Thus a person's natural cadence will vary according to their talents in the realm of muscular endurance and aerobic capacity.

Yes, everything about cycling gets easier at lighter body weights. Anything above a BMI of ~25 is uncomfortably heavy.

All that said, every winter and early spring I do high cadence drills on my rollers. A trainer works well, too. Once a week I pedal at very high cadences, around 115, for 15-30 minutes without a break. Obviously this requires a very low gear, perhaps the lowest gear you have. This won't necessarily increase your natural cadence for the reasons explained above, though it might. It will however make you a more efficient pedaler at any cadence. If you can't pedal that fast, pedal as fast as you can, right at the edge of bouncing, concentrating on messing with your leg motion by trying to pedal circles so as to lessen or eliminate the bouncing. It is possible to pedal at any cadence, all the way up to 200, without bouncing once you get the trick of it.