USD fork vs Telescopic Fork Differences



Ever wondered why some bikes are equipped with conventional telescopic forks while the others get upside down forks? First and foremost, let's get the differences out the way. A fork comprises of a spring and a damping unit inside. Here, the springs act as a compression unit while the dampers, with the help of oil, control its velocity. In essence, both telescopic forks and USD forks have almost similar working components. Despite this, the latter receives more preference over the former. The origin of USD forks dates back to the late 1980s when race teams turned the fork upside down to improve handling.

In a telescopic fork, the chrome part (stanchion) is positioned at the top and held together by a triple clamp while the slider (female portion) sits at the bottom. Turn the entire assembly over and you have an upside-down fork, where the slider sits up top, braced by the triple clamp, and the stanchion is positioned below. Needless to say, the section which undergoes the most amount of stress needs to be strong, and a fatter diameter fork is the best solution. A USD fork works perfectly well in this scenario. Since the fork assembly is essentially turned upside down, the slider now connects to the triple clamp. It’s also longer compared to conventional telescopic forks. As a result, it provides more support. It’s also less likely to flex under hard braking or turning speeds. Thanks to this, bikes with USD forks handle better and provide better feedback.

Additionally, damping cartridges on USDs are slightly better than the damping rod seen on telescopic forks as the damping or spring action is less progressive. The difference extends even further in terms of a fully adjustable USD fork which uses more complex internal parts. This enables the rider to adjust compression, rebound and damping by tinkering with the adjuster placed on top to suit his/her riding style. However, it does have its drawbacks as USD forks are a lot more tricky to work with and disassembling them is a task. On the contrary, conventional telescopic forks are easier to work with due to their basic architecture, be it changing the oil seals or just taking it all apart.

Telescopic Front Suspension

  • The telescopic suspension is cheaper to design and manufacture.
  • This conventional suspension is easy to repair if anything goes south with it.

So, Usually, the commuter motorcycle uses a telescopic suspension as they are not meant to be driven hard. Nor they have to suddenly change direction at high speed. Also, due to the lower cost telescopic suspension makes more sense at a low price. This suspension hampers the performance of high-end motorcycles.

Up-Side Down Suspension

This type of suspension is restricted to only high end and performance motorcycles. In the end, fast motorcycles are all about cornering speeds and lightning-fast direction changes. So, it is the USD fork that allows the rider to extract the most out of the motorcycle without any compromise in performance. This comes at a cost.

  • Exactly COST. USD front forks are way more expensive than conventional telescopic suspension.
  • However, these more advanced USD forks allow more bump absorption that makes the suspension more prone to damage.

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