Downhill Mountain Bike Frames
The most important part of any downhill mountain bike is the frame. The stiffness, weight, strength, durability, and maneuverability of any bike is dependent upon the construction of the frame.
Downhill mountain bike frames are usually constructed out of three materials - aluminium, steel, carbon fiber, or titanium. Aluminium frames are the cheapest frames available, due to the low-cost of aluminium and the relativ eease with which bike tubes can be constructed with the material. Aluminium bike frames are wonderfully lightweight and flexible, providing a solid, enjoyable ride for casual downhill mountainbiking enthusiasts. Aluminium doesn't rust at all, which is an advantage for a mountain bike, as it is sure to get wet and muddy quite frequently. But, aluminium will break under heavy usage, and the aluminium tubes that comprise the downhill mountain bike frame are easily dented, as they are thin-walled.
Steel (also refered to as cromoly in the mountain bike world) mountain bike frames are the most common mountain bike frames. Steel downhill mountain bike frames provide a highly durable, yet heavier ride, and are thus not ideal for mountain bikers seeking a lighter, faster frame. However, those of you seeking to begin a downhill mountain biking hobby would be well-suited to a stell frame; it will save you money, allowing you upgrade in the future if you ever felt the need or desire to do so. Beware - steel frames will rust, so make sure that your paint job is well-maintained by either you or a bike technician to ensure that your frame strength and viability lasts!
Carbon fiber, or composite frames (as they are called if the carbon fiber is combined with aluminium or other metals to make it stronger) are very light, durable frames to look for when purchasing a mountain bike. Carbon fiber frames can be tailored to meet the needs of every cyclist and their specified ride. They offer a very stiff, light ride for serious mountain bikers. They, however, are not as durable as steel or aluminium frames: a hard collision will shatter a carbon fiber frame. Many downhill mountain bikes will boast at least one component made from carbon fiber, though, be it the fork of the mountain bike, the stem, or the actual frame itself.
Titanium is the strongest, most expensive material available for downhill mountai bike contstruction. As the material itself is expensive, and requires a great deal of exertion to shape, titanium frames are the most expensive frames available to mountain bikers today. However, despite the cost, titanium downhill mountain bike frames offer some marked advantages over steel, aluminium, and carbon fiber frames. As titanium is incredibly durable, it won't break (and will be hard-pressed to warp or bend) if the downhill mountain bike gets into a collision with any obstacles on teh course. As titanium never rusts, there is no need to maintain a paint job on the bike, and thus negates a common mantainence complaint about downhill mountain bikes. And, titanium is veyr light, and very stiff, offering one of the most expediitous rides available to all downhill mountain bikers today.