Welcome to BIKES 101
Intended Use for Different Bike Styles:
Road Bikes: Road bikes have a 700c wheel, which is larger in diameter than a 26" wheel, but very narrow to reduce rolling resistance. Generally Road bikes are geared higher than mountain bikes with fewer climbing gears. They are available with either two or three front chain rings and eight to ten speed cassettes in the rear, depending upon the level of components. Road bikes are fairly enthusiast oriented and are used for long rides at high speeds. The most common example of road bike riding is the Tour de France. The levels of Shimano component groups from entry level to top of the line are Sora, Tiagra, 105, Ultegra, & Dura-Ace.
Mountain Bikes: Mountain bikes have multiple uses but were originally intended for off-road use like you would see at South Mountain. They are geared for climbing as well as descending and are available with 21- 27 possible gearing combinations. The frames are generally made of hi-tensile steel, for the entry level bikes, or more commonly, aluminum to save weight. Most mountain bikes now come equipped with front suspension forks and and some with rear suspension as well, called full suspension or "full sauce". In full suspension there are different styles, bikes with short travel rear shocks, called cross country, and bikes with longer travel rear shocks called downhill, freeride, and all-mountain. The seating position on a mountain bike is generally going to be fairly aggressive, stretching the rider out over the bike to distribute weight to both wheels for power in turning as well as pedaling, although in the entry level bikes it will not be as aggressive. Many riders now ride entry level mountain bikes on the road because of the wider tires and the price difference as compared to road bikes. The levels of Shimano mountain bike components from entry level to top of the line are Tourney, Altus, Acera, Alevio, Deore, Deore LX, Deore XT, Deore XTR.
Sport Comfort Bikes: Sport Comfort bikes are a combination of a mountain bike and a beach cruiser. They have a mountain bike style frame, most commonly made of aluminum, but has been shortened to sit the rider in a more upright position to alleviate pain in the lower back. Other sport comfort features include an adjustable stem which rotates like a ratchet in order to bring the handlebars up higher. Usually the handlebars also have more rise to them than a mountain bike handlebar. Sport Comfort bikes also come with a suspension seat post and a smoother tire to reduce noise and vibration. Sport Comforts come with and without front suspension. These bikes are designed for mostly road use and some light dirt like you would find on a canal. They run mostly Shimano mountain bike components.
Hybrid Bikes: Hybrids are a combination between a mountain bike and a road bike. They are very similar to a sport comfort in the features provided, the main difference being the size of the wheel. Instead of a 26" wheel they come with a 700c wheel similar to a road bike, although the tires are generally wider. The hybrid design is mostly intended for on road use at higher speed than the sport comfort. They run mostly Shimano mountain bike components.
Freestyle BMX: Freestyle BMX bikes come in two different styles, dirt and street. Dirt jumpers come with knobby tires and either two pegs or with out pegs all together. Street bikes come with smooth tires, four pegs and front brakes. These bikes are intended for trick riding and the pegs on the axles are used to slide on rails or concrete. These bikes, when used in this extreme manner will need more maintenance and repair than bikes being used under normal conditions. The more durable freestyle BMX bikes add strength with extras like doublewall wheels and three piece cranks. Unlike most bike styles, weight is not a huge concern and because of the intended use they may be fairly heavy.