The manual clutch is an endangered species. Most cars don’t have them anymore, now that those newfangled automatic transmissions have caught on in popularity. Of course, there’s an analogue to the clutch in an automatic transmission, but they aren’t an active part of the driving experience unless you’re driving a car with a manual transmission.
Basically, a clutch is the device that lets you change gears without your transmission falling out of your car into the middle of the road. Seriously. Use that clutch improperly and large, expensive pieces of your car will shudder in the grip of certain death and propel themselves six feet away from you car, with no heed for other the vehicles that might be occupying that space.
When the motor turns the wheels, the motor isn’t attached directly to the wheels. The energy is transmitted to the wheels by the transmission. Back when cars were first being designed, engineers discovered that having the wheels connected directly to the engine was a bad idea. When you had to go up or down hills, for example, it was very hard on the engine. Imagine riding a bicycle down a steep hill without coasting – imagine you have to keep your feet on the pedals and use the force of your legs to keep the wheels turning at a constant speed. Chances are, you couldn’t do it – you’d have to take your feet off the pedals.
The car equivalent in this analogy is something known as blown rods, which occurs when your pistons break free and are tempted to take flight right through the hood of your car. This was – in a word – bad.
Fortunately, engineers came up with the transmission to solve this problem. They did this through the magic of something called the gear ratio. To give you a short course in mechanical engineering, gear ratios allow you to have gears moving at different speeds but all playing nicely together. You could have a fast moving gear attached to a slow moving gear, attached to another fast moving gear, and they’re all going to work happily together.
Cars needed to move at different speeds at different times, sometimes in quick succession. Consequently, the gear ratios of transmissions quickly developed into 1, 2, and 3 – first, second, and third gears.
First gear allows the car to move slowly, but it’s a powerful gear transmitting the full power of the engine to the wheels. Second gear gives you a moderate amount of power and speed, while third gear is where you get more speed but less power. It’s not that the upper gears are weaker; they’re just designed to spin faster to take advantage of the momentum of the car at higher speeds.
The clutch is that magic piece of machinery that allows you to take advantage of those different gear ratios. Depress the clutch and it takes the transmission out of gear. Use the stick shift to choose the next gear, and as you release the clutch, the transmission re-engages in the new gear. Of course, this is all easier said than done if you’ve never driven a stick shift before, but with a little practice and a healthy bit of patience, you’ll eventually get the hang of it.
