Mountain Bike Suspension Systems for Off-Road Biking

In the past mountain bikes had a rigid frame and fork. In the early 1990s, the first mountain bikes with suspension forks were introduced. This made riding on rough terrain easier and less physically stressful. The first suspension forks had about 1½ to 2 inches (38 to 50 mm) of suspension travel. Forks are now available with 8 inches (203mm) of travel or more (see above under “Design.”) Bikes with front suspension and rigid, non-suspended rear wheels, or hardtails became popular nearly overnight. While the hardtail design has the benefits of lower cost, less maintenance, and better pedaling efficiency, it is slowly losing popularity due to improvements in full suspension designs.

Many new mountain bikes integrate a “full suspension” design known as Dual Suspension or “Dualie”, meaning that both the front and rear tire are fitted with a shock absorber in some form as the wheel attaches to the bike to provide a smoother ride as the front and rear wheels can now travel up and down to absorb the force of obstacles striking the tires. Dual suspension bikes are considerably more expensive, but this price increase brings an enormous performance upgrade as dual suspension bikes are much faster on downhill and flat sections than other forms of the mountain bike. This is because when the wheel strikes an obstacle its tendency is to bounce up. Due to some forward energy being lost in the upward movement some speed is lost. Dual Suspension bikes solve this problem by absorbing this upward force and transmit it into the shocks of the front and rear wheels, drastically decreasing the translation of forward momentum into useless upward movement. Many bikes have dual suspension including downhill, freeride and mountain, although some bikes are built only to have front suspension e.g. dirt jump, some mountain. This makes them lighter and easier to control while in motion.

The advantages of dual suspension are increased comfort on rough terrain, and improved handling over obstacles. Disadvantages of rear suspension are increased weight, increased price, and with some designs, decreased pedaling efficiency. At first, early rear suspension designs were overly heavy, and susceptible either to pedaling-induced bobbing or lockout at certain points of the suspension arc or travel. One of the most popular rear suspension designs to solve these issues has been the ‘Horst Link’ which first appeared with the AMP series of bikes, and was later adopted by Specialized and many other mountain bike manufacturers.