How do you know how hard to ride and which gears to use? The sport of bicycling has three major themes: efficiency, practicality, and self-sufficiency. Gearing is all about efficiency. You want to ride in the gear that will allow you to spin at a cadence that is comfortable yet taxing (here's the good ol' overload principle again). Spinning means pedaling with quick, even strokes at a comfortable and efficient cadence; this causes less fatigue in the legs than when pedaling at a lower cadence in a more strenuous gear. To spin, the selected gear has to be at a tension that allows you to push the crank (what the pedals are attached to) without straining. Cadence refers to the rhythm and number of revolutions per minute that you turn the crank. To help you visualize this: serious cyclists spin at 90 to 110 rpms, and recreational riders spin at roughly 70 to 90 rpms. Cadence will vary depending upon many conditions, such as whether you are riding on a smooth road or rugged trail, or up or down a hill.
The beauty of thinking about your cadence and spinning is that it keeps you from pushing a gear too hard, and that helps you avoid straining your muscles and other injuries. Once again, more is not always better.
Mountain bikes allow you to ride on a wide variety of surfaces, including grass, dirt, rock, puddles, and paved roads. Mountain bikes are bigger, heavier, and more stable than road bikes, and at rest are more comfortable than road bikes. However, when you are riding a mountain bike up or down a dirt path, and over rocks or tree roots, comfort becomes a relative term. Mountain bikes have three chain rings (for gearing) and numerous gearing options that make it possible to ride through all types of challenges. The wheels and tires are larger than on any other type of bike in order to tackle the variety of terrain. Mountain bikes even come equipped with shock absorbers to help absorb some of the impact from riding over rough areas.
Knowledge of how to remedy a flat is important. You'll need to always bring a patch kit with you, which can be kept inside your saddlebag. Having the equipment with you can make the difference between having a fun experience or a disappointing one. The last thing you want to do is walk your bike home after you've already ridden for a few miles.
Hybrid bikes are a combination of mountain bikes and road bikes. They are best for those who prefer to ride on roads (great for commuting) but want greater stability and comfort than what road bikes offer. Hybrids are slower than road bikes and not nearly sturdy enough for serious mountain biking. They are heavier than road bikes but not as bulky or as heavy as mountain bikes.
Road bikes are made from various grades of steel, aluminum, carbon fiber, and titanium. Generally, the lighter yet stronger materials command the heftier prices.