Advancements in Motorcycling: Hydraulically Dampened Telescopic Forks

Motorcycles — and most automobiles — have been through many changes since technology and gasoline first made them possible. Let’s look at one of the earlier innovations that made motorcycles easier to ride with the now extremely common, hydraulically dampened telescopic fork. We'll explain what came before this type of fork, as well as what led to the concept and how the telescoping fork works today. Keep reading to learn more about motorcycle history!

What came before the hydraulically dampened telescopic fork?

Motorcycle wheels were previously held to the frame by steel girders by links capable of pivoting. Scissor type dampers were used to absorb any impacts or provide a bit of flex – though by modern standards, before 1939, they didn't work especially well for the purpose.

The inclusion of more powerful brakes, which was the result of more powerful engines and better quality gasoline actually led to the girder fork becoming obsolete. Brakes put more stress and pressure on the girders, which they weren't capable of handling.

How does a hydraulically dampened telescoping fork work?

Telescoping forks are a fairly simple technology. Within a pair of tubes, you'll find internal springs (and in some cases, external too) that are capable of both absorbing the impact of ground forces and moving an often light-weight internal back and forth to continue the movement of the springs.

Throughout the decades that telescoping works have been available, one challenge has been to keep the fluid pressurized enough to provide the necessary shock absorption and to keep it moving. In some models, a piston or bladder has been inserted that is capable of moving the hydraulics to maintain pressure.

The huge advantage of hydraulics is their responsiveness. Steel girders were stiff and rigid. A hydraulically dampened form was reactive. The air, oils, and hydraulics moved and made it possible for the springs to take impact while also providing a more natural, dynamic ride.

The springs within telescoping forks are helpful, though subtle. When riding on a regular road, springs are uncoiled and don't need to do much. When bumpy roads or inclines arrive, the springs are forced back and move the hydraulic fluids and air up, causing compression and taking the impact off the driver. Road impact gradually goes to the frame itself.

More modern tubes now work a little differently. The up and down movements of the form create heat due to the oil and piston, which doesn't help damping. Since the fork system has two tubes, one controls rebound damping while the other controls compression. The oil doesn't need to heat up when not being used for the same purpose, so it isn't as compressed or moved.

What impact did the telescoping fork have on motorcycles?

With the introduction of a more dynamic and responsive riding system, motorcycles became easier to drive and much more comfortable to ride over bumpy roads. They also made racing and jumping easier and less likely to have a serious impact on a driver's knees and the rest of their body. Imagine doing a motocross jump and landing on steel girders with little flex to them – no thanks! Thanks to simple gravity, compressed air, moving oil, and springs, at least some of the impact was taken by the machine instead of the rider.

The telescoping fork is also cheap to manufacture. Steel isn't needed – just hollow metal tubes that are relatively lightweight compared to steel, which is much denser. The internals are not too complicated either, and are closely related to more substantial hydraulics used on cars.

Just like the introduction of aluminum in frames, using a lighter version of steel girders allowed the motorcycle to either have the potential to go faster with the same engine, or use a smaller, more fuel-efficient engine to go the same speed. Americans would turn this concept somewhat on its head, though, and generally demand faster engines as hydraulics became better.

Many motorcycle owners also care about how their bikes look and a telescoping fork looks more standardized and clean compared to the steel blocks of previous decades.

Needless to say, without telescoping forks, motorsports would look very different today. These innovative devices have revolutionized the world of motorcycling, enhancing both performance and safety in ways that have forever altered the landscape of the sport.