If you’re relatively new to cycling, or perhaps even if you’re not, you no doubt have found yourself wondering “What the heck do I do with all these gears? And do I really need that many?” Well, let’s see if we can take some of the mystery out of gearing for you.
First, there are two general types of gearing systems on bicycles today. The most common is a “derailleur” system, which has multiple toothed sprockets on the rear wheel, and also often on the front “crankset” (the thing your pedals are attached to). Don’t let the French name intimidate you... basically all a derailleur does is move your chain from one sprocket to another sprocket, and you don’t really need to know the details of how it does that - unless you plan to do your own maintenance, that is. But for simply riding a bike, suffice to say that’s all it does.
Without getting into a lot of math or physics, the first thing you need to know to understand gears is that on the rear wheel, a bigger sprocket (larger diameter, more teeth) is easier to pedal, but doesn’t propel you forward as fast. So those are the sprockets you want to use when you are going UP a hill.
The smaller sprockets move you along faster, but are harder to pedal, so those are for going DOWN a hill. As you probably have guessed by now, the middle ones... those are for level ground and comfortable cruising.
Now, if you have multiple sprockets (called “chainrings”) on the crankset, the opposite is true - smaller = easier, bigger = harder. Typically, a harder to pedal gear is known as a “high” gear and an easier one is “low” gear, much like in your car.
The other type of shifting system you’ll find on a bike is what is known as an “internally geared hub”. As you might imagine, that means all of the various size sprockets and such are inside the rear hub... that big cylinder at the center of the back wheel that the spokes attach to. You can determine if that’s what you have pretty simply ... if you only have one visible sprocket on the back, and yet you have a shifter that indicates multiple gears, you have an internally geared hub.
For examples of both types of bikes, look at the pictures in the media gallery above.
There are some bikes that combine the two systems, but those are not as common. Regardless of which type you have, HOW you use them to ride comfortably and efficiently is pretty much the same.
Unlike your car, there is no need to shift through the gears in order, so you don’t have to worry about starting in first gear, getting up to speed, shifting to second, etc. All you really need to think about is that if you feel like you’re working too hard (pushing hard and slow on the pedals) you should shift to a lower gear, and if you feel like your feet are flying about madly and you’re going nowhere, you should shift to a higher gear. And remember... low is for uphill, middle is for level, high is for downhill. Pretty simple, no?
Now, in terms of actual operation of your gears, first, you need to identify the “shifter” and figure out how to operate it. Generally shifters on bikes with flat handlebars are of two types:“twist”, which are part of the handgrip and are actuated by twisting them, as the name implies, and “thumb” shifters, which are typically single or double levers you operate with your thumb.
Road bikes with dropped handlebars have different shifters, either attached to the bike frame itself (rare these days), at the end of the handlebars, or integrated into the brake levers.
Whatever the type of shifter, you need to experiment a little to figure out what action shifts you into low or high gear. It’s pretty obvious once you try it, and with a few rides it will become second nature to know what to do. Of course, many shifters have actual numbers on them, in which case, the higher the number, the harder the gear.
One important difference between derailleurs and internally geared hubs is that a derailleur MUST be shifted while pedaling, while it’s typically best to STOP pedaling when shifting an internally geared hub.
One very nice feature of the internally geared hub is that you can shift when standing still, which means that if you come to a stop and realize you’re in the “wrong” gear, you can change it before you set off. This feature, combined with the fact that the system is protected from weather, is why internally geared hubs are now appearing more on commuting and transportation bikes. With a derailleur system, you really shouldn’t shift when standing still, as it will cause a jarring “jump” when you start pedaling, and you might damage things as well. Finally, while you must be pedaling when you shift a derailleur, it’s best to ease off your pedaling force as you make the shift, so the chain can move easily.
Now back to the beginning: Why does your bike have so many gears, and do you need that many? It depends on how and why you ride. If you travel long distances, carry heavy loads, or are really concerned with optimizing your body’s efficiency (for competition, for example), then more gears are generally beneficial. Casual recreational cyclists, on the other hand, probably don’t need quite so many, and may even find them intimidating. That’s why I often advise the proud new owner of a bike with 24 or so gears (3 chainrings X 8 sprockets = 24 gears) to simply put the front shifter in the middle gear and just use the right shifter until they are more comfortable with the whole thing. In most cases, those 8 gears will be just plenty for most of your riding. Truth be told, if you asked many experienced cyclists, they’d admit they do the majority of their riding in the middle chainring. With practice and experience, you’ll find when the time is right to drop into the smallest chainring (climbing big hills) or shift onto the largest (zooming down big hills, or that rare tailwind).
Finally, I’d just like to assure you there’s no magic or great mystery to gears. It’s NOT as complicated as you think. And even if you get it “wrong” sometimes, nothing truly bad is going to happen. Give it some time, and you’ll sooner or later find yourself wondering what the big deal was in the first place.