What Are All Those Gears For? Or, More Simply, Shifting Explained

Gears on bicycles are really designed to make your life, (the rider) easier. So many of our clients come in the shop and ask for a bicycle that is both "easy to ride," and "will work in their neighborhood." Since their neighborhood is pretty much like every other Atlanta intown neighborhood, there are probably some hills. Gears make getting up (and down) those hills easier, and shifting today's modern bicycles is very easy. This means you can ride your bicycle easily, anywhere you want to go!

More Range, Easier Transitions, More Gears
Most new adult basic bicycles are at least 21 speed. 21 speed means there are 3 chainrings on the front and 7 cogs on the rear. 3 times 7 equals 21 - but don't get hung up on numbers. Number of gears has more to do with the transitions between gears, then the range between gears.

(insert pic of 7 speed cypress cassette, 8 speed cypress dx cassette)

The rear cogs - the freewheel or cassette - on these bicycles have the same range of low, easy pedaling, to high, harder pedaling. Easy gears let you climb hills without struggling, hard gears have more resistance and let you go faster. The big difference as you can see, is on the low range. The 8 speed (shiny, silver) has one more cog between the space between the second to the lowest (biggest) cog and the lowest cog. This means that the transition when shifting on the easy side of the spectrum is smoother, the bicycle shifts easier and you have one more choice of lower gear.

In the front, both of these bicycles have 3 chain rings. The bicycle on the left is a mountain bike, the bicycle on the right, a road bike.

(insert picture of atb and ocr)

The mountain bike has much lower gears than the road bike. Oddly enough, and this is one of those amazing things about bicycles, bigger chainrings in the front mean higher, or harder gears. Smaller chainrings mean lower, or easier gears. Mountain bikes are designed to go places not easily accessible to cars, like steep twisty terrain, and go there easily. Road bikes have less rolling resistance due to thinner, high pressure tires and they go places are graded (not so steep) for cars, so they are geared to go faster with less effort. Both of these bicycles are geared for a wide variety of terrain, with small differences between the rear cogs so the transitions between gears are smoother for easier shifting.

Think of yourself as the motor
In a manually shifted car, where you operate the gears (more than shifting from Park to Drive), you shift to make it easier for the engine to do it's work. An automatic transmission in a car also shifts gears to make it easier for the engine to work.

Bicycles aren't cars, they have more gears and you might not start from a stop in the lowest gear a bicycle is capable of, but - you do shift to make it easier on the motor, which is you. You are going to shift to keep moving at a cadence (cadence refers to the speed in which you are turning the cranks with the pedals, measured in revolutions per minute), that is comfortable for you to maintain and smooth - not jerky. A higher cadence is going to provide more of an aerobic workout (the kind of exercise that's good for your heart) but we aren't focussing on race training here - just riding your bike more effectively. After you get the bicycle moving and are riding along, you shift gears when you feel your legs strain or want to increase or decrease your cadence. When you approach a hill, you gradually shift to easier gears in order to climb that hill pedaling as easily as you desire.

Shifting Smoothly and Effectively
The bicycle drivetrain hasn't really changed since bicycles started to have gears, oh, back in the 1930s or so. There have been pretty major advances in the parts that do the shifting (the mechanic at your bicycle shop refers to those parts as the "drivetrain"). Still, nearly all bicycles now and in the past, have a drivetrain that consists of a chain and front and rear derailleurs, cogs in the rear and chainrings in the front. The cable actuated derailleurs shift the chain to different cogs and chainrings when the rider operates a gear shift mechanism, which is attached to the cable. It's very simple, very efficient and only operates effectively when the rider is pedaling. So, always be turning the cranks - not just coasting the bike, when you shift.

Since the system is entirely mechanical, it is also a good idea to remember to not make big jumps between wide gear ranges all at once. Shift easily, one gear at a time. Most modern bicycles use index shifting, which simply means the shift mechanism the rider is operating has "clicks" or indents between gears. The click is usually both audible and has a certain hand feel.

So if you shift one gear at a time, while pedaling, you almost are a shifting expert. The last most important thing to remember to shift effectively is to take the pressure off the pedals on a gear change. Pedal lightly and smoothly. Picture coming up to a hill in a high resistance gear and not paying attention to the fact that it is hard to pedal. You are standing up on the pedals grinding away before you decide to shift. You shift and the chain makes a grindy, clanky noise and drops right off the front chain ring and jams up in the bicycle frame. Not fun for you or the bicycle. So the answer is to shift before you need to, to move the chain over that wide range of gears that goes from a high resistance gear to a low resistance gear, as smoothly as possible. Also, sit down and pedal lightly.

Great! I Know How My Bike Shifts, Which Gear Should I Be In?
The answer is, the easiest gear to maintain your pedaling cadence for the terrain you are riding on. And this is why you have so many gears. If you stand over the front of your bicycle and look down you should see between 1 and 3 chain rings in the front. Your left shifter operates those

(picture of single chainring, 2 or 3 chainrings from the riders eye view)

Now remember, in the front, the smallest chain ring is your easiest gear. On all the bicycles we sell at Bicycle South, that front derailleur is operated by the left shifter mechanism. The front brake is also on the left side of the handlebars, so it is easy to remember, left side front brake, right side rear brake. Left shifter shifts the front derailleur, right shifter shifts the rear derailleur. As some of the bicycles we sell have numeric indicators for the gears, that front easy gear is referred to as "1". In the rear the biggest gear is also referred to as "1," and on a bicycle with numeric gear indicators on the shifters you will see a "1" as well.

1 in the front goes with 1,2&3 in the rear. 1 in the front and 1 in the rear are the lowest gears on your bike and get you up any hill. When you get to the top of that hill and want to pedal on the flat with more resistance, you will find yourself shifting to higher numbers on the right - rear of the bike. That's good, but each of those chainrings in the front goes with a certain combination of cogs in the rear. When you are at the top of the hill, and shifted into 1 in the front and 3 in the rear, and still want to have more resistance and make the bike go faster, shift to 2 in the front and 4,5 or 6 in the rear. Lots of people pretty much just use those gears for riding around town with a lot of stop and go and not so many hills. If you find yourself wanting to go fast, shift to 3 in the front, and 5,6 or 7 in the rear. Now if you look between your knees (go ahead and stop and put your feet down) you should see that the chain makes a nice straight line between the gears in the front and the gears in the back. When you use these combinations of gears together, you are not making big jumps between gears, which is kind to your chain and your other drivetrain parts, as well as your knees!

Don't Make Your Chain Cross!

(picture of cross chained bike from the rear, picture of der and chain all twisted up from the side)

This bicycle is cross chained. It's in 1 in the front and 8 in the rear. It'll go into that combination of gears, but the chain rubs on the derailleur, the chain may jump off the front cog and end up resting on the bicycle frame, and yes, this bicycle is cross!

Here is another cross chained bicycle. This one is a racing bicycle with only 2 chain rings in the front and 10 in the rear. This bicycle is cross because it is high in the front and low in the rear and the derailleur is all stretched out and in an unhappy position.

(picture of cross chained road bike from the rear, side view as well)

Cross chaining wears out components and is bad for the derailleurs. Don't do it because you will be cross as well!

Ok, What Else?
Again, shift one click at a time, one side at a time. Don't double shift, front and rear at the same time. Shift before you need to, or to accommodate changes in terrain, (even a head wind in the flats). You'll find that experienced cyclists shift a lot and we don't even think about it. Shifting a bicycle is not as difficult as shifting a manual car, you can't let the clutch out too fast and kill the engine. Children become good at shifting fairly quickly. So go ahead - buy that bike with gears, you'll be glad you did!