Do you have a computer that shows cadence? If not, get one, a cheap one works fine. I use a Cateye Astrale, about $35. So here's an odd thing: It turns out that most folks running long distance run at about a turnover rate of 90 strides a minute. And, oddly enough, a bike cadence of about 90 seems to suit most folks the best. My guess therefore is that it's actually built in to our genes.

So try turning the cranks much faster in a lower gear. Pick up the cadence about 5 beats a week. There is quite a period of adaptation, but it's worth it. At first, you'll go a little slower because your muscles are fighting each other. But gradually you'll develop the neuromuscular coordination to be able to ride at a 90 cadence at the same speed you're riding now and with less effort. You'll find your recovery is much easier, too. A problem with riding at a low cadence is that you burn too much glycogen, and glycogen is hard to replace every day.

You notice that if you spin faster, you use your hamstrings more. Yes, that's true. Nothing wrong with that. You want to have a nice smooth spin. Assuming that you use clipless pedals or toeclips, push forward at the top of the stroke, only push down gently, pull back at the bottom and unweight the pedal on the upstroke - don't pull up. Imagine that you are turbine powered. This all takes a while to develop. Your muscles have to get used to the motion. Don't get discouraged.