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| Explaining The Parts Everything you wanted to know, but were afraid to ask. Let's face it. The world of cycling is full of strange sounding names and acronyms too numerous to remember. Don't worry so much about the brand and model names, it's the performance they deliver that's important. Bike shop personnel should be able to explain any differences in quality and performance, but here's a little primer on what you might see when you visit your local professional bicycle dealer. FRAME TUBING MATERIALS The most important component of a bicycle is the frame. You can always upgrade the other parts later, but a big, heavy frame is always a big, heavy frame. A bike's frame material influences how much it costs, weighs, and how it handles. The least expensive bikes use hi-tensile steel. As you go up in price, bikes will have more chromoly (a blend of steel, chromium, and molybdenum). For example, a bike may have a chromoly front triangle (main frame) while the rear triangle (seatstays and chainstays) is hi-tensile steel. All-chromoly frames usually have special treatments, such as thinner wall thicknesses at certain areas, called "butting," that shaves weight while maintaining a high degree of strength. The most expensive frames are made from even more exotic chromoly with added ingredients for specific characteristics, butted aluminum, carbon fiber, or titanium. Steel is still the most commonly used metal in bike frame construction. (Some bike companies will hide hi-tensile steel in the head tube, bottom bracket, or rear triangle.) Chromo, as it's sometimes called, is lighter and more responsive than hi-tensile steel. Hi-tensile steel frames are very durable and fairly responsive, but are relatively much heavier than a butted chromoly frame. Chromoly tends to be much more "lively", possessing a natural compliance that actually absorbs small road and trail shock. Brand names you may see include Tange, True Temper, and Columbus. Over the last several years aluminum has grown in popularity and gone down in price as a material for bike frames. Aluminum tubes tend to be oversized; that is, they're larger in diameter than steel tubes. The material makes for a rigid, responsive bike. As with chromoly, butting the tubes lightens the frame's overall weight. However, aluminum will remain stiff when butted, as opposed to chromoly steel, which becomes more compliant. The rigidity of aluminum make for excellent all-out acceleration, as well as the main fuselage (main frame) of dual suspension bikes. Metal matrix (usually a combination of aluminum and a ceramic) bikes are on the cutting edge. Easton, Alcoa and Reynolds are the most common brand names. In recent years bike companies have started experimenting with other frame materials, some of which are quite exotic and expensive. Titanium has become more available as demand has increased. Fabricators can then order special tube diameters to better facilitate bicycle designs. It is still a fairly rare material, and is finicky to work with. The ride is much like a good butted chromoly frame, but with even less weight and better durability. The interesting thing about titanium is that there are only a few major manufacturers. So if you see a bicycle frame made of titanium, more than likely it has been build by one of two or three makers. This helps bring the cost down, especially since they are built in larger numbers. The most expensive version of a titanium frame is one built by a custom maker. This is where you get personalized features and measurements built to order. Finally, carbon fiber delivers the most shock absorbent ride of any of the frame materials. Although it's not shock absorbing like a suspension, it diffuses the vibrations that are sent through it. You really have to ride it to understand. There are two types of these frames, the first being molded from one piece, also called a monococque design. These are very light, and because they are laid up by hand, the fibers can be directionally positioned to decrease vibration and increase torque stresses. These frames are not quite as stiff as some steel and most aluminum frames. The second fabricating technique used with carbon fiber is lugged, either using aluminum lugs or special lugs also made of carbon fiber. These deliver a more rigid ride than the monococque frames but at the expense of some of the shock absorption and light weight (lugs often have to be aluminum, adding material), though they are less expensive to produce. Carbon fiber frames are highly prized because of their weight and smooth ride, but they aren't cheap either, with most complete bikes starting at over $900. COMPONENTS Components, the mechanical parts on a bicycle, are usually made by companies other than the one that built the bike. They might come in "groups" from one of two giant international companies, or they might come from specialist companies who make only certain kinds of parts. In some rare cases, such as small custom companies, a bike manufacturer will produce parts as well. Buyer's guides and advertisements typically list these parts. A company might boast of, for example, GripShift shifters, Avid brakes, Tioga handlebars, Ritchey tires, Mavic rims, Wellgo pedals and a WTB saddle. How well these diverse parts work with the frame dictates the bike's performance. A "group" is a set of drivetrain parts (such as derailleurs, shifters, and chainrings) designed to work together. Many bike companies start with a group, then add the other party parts to make up the rest of the components. Bikes in the same price range usually have similar groups of components. Sometimes competing companies will use different parts and groups to try and distinguish their bikes. "Shimano" is a name you'll hear a lot. Shimano is the major manufacturer of bicycle components in the world today. It produces parts for mountain, road and hybrid bikes. There are a variety of shifting mechanisms that Shimano currently offers, the most popular being the RapidFire Plus underbar shifter for mountain and cross bikes. Shimano is the finest example of integrating component groups for maximum performance. Shimano's Dual Control Lever for road and touring bikes is also one of the most innovative and efficient designs on the market. The integrated brake lever/shifter mechanism allows you to brake and shift without moving your hands off the handlebar, as with standard frame tube-mounted shifters. As advanced and popular as Shimano's mountain and road groups have become, maybe the most significant achievement has been for the cruiser bike. The Nexus internal gear ("no derailleur"!) rear hubs and incredibly easy-to-use shifters have made riding a bicycle pure fun again! Whichever group you find on the particular bike your looking at, you can be sure that if it has Shimano drivetrain components, you'll be getting the best value for your money. GripShift has made a presence with their extremely popular GripShift twist shifters and ESP derailleurs. The performance is excellent for the rider seeking an alternative to Shimano. It has broadened its offering even further by its purchase of the Sachs brand name: those products have become a part of GripShift as well. Pedal Power: You will find two distinct types of pedals on bikes too, either platform pedals, with or without toe-straps, or clipless pedals. Platform pedals are pretty self explanatory; some use toe straps to secure your feet on to the pedal. They are great for casual riding and cruising around town, and toe-straps are easier to use than most new cyclists think! However, any experienced cyclist will tell you, clipless pedals are the way to go for optimum performance. Without the bulky toe-straps, a tiny cleat in the bottom of your shoe clips in to a mechanism in the pedal. This provides efficient pedal power, and to "clip-out", simply twist your foot and you are free. Clipless pedals aren't for everyone, and they do take some time to get used to. However, if you plan on being a serious cyclist, clipless pedals are the way to go. STOPPING POWER Linear-pull cantilever brakes are the choice for most mountain bikes, cross bikes, tandems and touring bikes because they are inexpensive, powerful and easy to maintain. A major breakthrough in braking performance, the sidepull linear-pull cantilever, uses a unique cable routing system. Its tall profile produces an amazing amount of power with a very sensitive feel. Road bikes usually use lightweight caliper brakes which provide good stopping power. Aside from occasional adjustments and brake pad adjustments, they offer virtually maintenance-free operation. Among the more exotic brake options, found mostly on tandems or mountain bikes, are disc brakes (hydraulic or cable actuated) and hydraulic cantilevers. These systems are generally more expensive, but the stopping power is incredible! Disc brakes were once only found on high-end downhill bikes, but because of their great performance, you can find disc brakes as standard equipment on many cross-country bikes now too. ROUND AND ROUND Often called knobbies, mountain bike tires are very durable, resist flats, cushion the rider from a rough road or trail, and provide excellent traction. Different tread patterns are suitable for different kinds of terrain, from mud to loose gravel and rock. They are sometimes referred to as 26-inch tires as they are mounted on rims that are 26 inches in diameter. Less expensive tires have a steel bead (the thing that helps hold the tire on to the rim), while more expensive tires have Kevlar beads, which are much lighter for decreased rolling resistance. You'll find the 700C-size wheel on most road and cross bikes. Cross bike tires come in a variety of styles for different types of terrain, from slicks for road/city use to knobbies for off-road use. Depending on the width of the tire, they can provide a surprisingly smooth and cushioned ride. Road bike tires are built for speed, not comfort. These skinny, high-air-pressure tires are very fast, but offer little cushion from the road and are prone to punctures. Touring tires, while much like cross bike tires, are not quite as stout and offer reduced rolling resistance with a bit more stability and durability. |
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