Shifting Gears – Motorcycle Basics

Before you set out on the road, you need to know a little bit about how a motorcycle operates. First, some super simple physics.

Staying Upright

Did you ever wonder how a motorcycle can stay upright when it’s moving? Everyone knows that sitting still, a bike (and its rider) will fall over unless they have support. But a moving motorcycle somehow stays up without a lot of effort. Weird.

The technical answer involves some complicated physics about angular momentum and torque. But let’s skip all that and take an everyday example. Hold a bat, heavy end up, in your palm. It will tend to fall over. It’s statically unstable. But wiggle your palm to keep it continually right under the heavy end, and the bat will stay upright. It’s dynamically stable. Something similar works with motorcycles.

When you drive forward friction and your small balancing movements constantly adjust the center of gravity of the bike and rider. The result is similar to the upright bat. The bike and rider stay upright.

Maneuvering the handle bars to get that smooth rideMoving forward

Over the decades there have been several different designs, but today most motorcycles have standard operating configurations. The steering mechanism is a simple lever. Other types, like steering wheels, joysticks, and others have been tried.

The right handle grip contains the throttle. The original meaning of ‘to throttle’ is ‘to slow down or hinder’. Here, it has the opposite meaning. Twist it back toward you and the engine gets more gas. With the brakes off, you’ll go faster. Common knowledge.

On the left handle grip of the handlebar is the clutch. Pull it in to change gears, then release – not too fast, not too slow. Also fairly well known. Not too many motorcycles have automatic gear changing mechanisms, but they exist.

Beneath your left foot is the gear shift. Squeeze the clutch lever, ease off the gas, and move the gear shift up or down. Then release your left hand, push the throttle and go.

Slowing Down

The front brake lever is attached to the right handle grip. The front brake supplies most of the friction needed to slow down the bike. In some cases, as much as 80%. Pulling it too hard and too fast can flip the bike (and you) over, especially on downhill angles.

Near the foot peg on the right side is the rear brake lever. Push it down with your right foot, and the rear brake mechanism is engaged. Usually, the front and rear brakes are used simultaneously. Feathering the front and rear can cause undue wear on one or the other.

Some bikes have linked braking systems. Pressing the rear brake engages part of the front brake. Synchronization is key to smooth, safe stops. Most rear brakes today are disc type – one or a pair of pads squeezes against a metal disc in the center of the wheel and friction slows the bike to a stop.

Turning off

Most bikes today have a ‘kill switch’. Sometimes reaching for the key to turn off the motor can cause the bike to become unbalanced. Sometimes you fall off and have to shut off the engine in a hurry. In either case, using the kill switch to kill the motor fast provides a safety backup.

There are lots of variation beyond the basics. Some bikes have an old-fashioned, but still frequently used, kick starter. Others have a push button starter. Some have sidecars, custom suspension, electronic de-fogging mirrors, mileage and GPS computers… the list is endless. But they all have the necessary components discussed above. If they don’t, your bike is busted.