Shifting Gears to Accelerate Quickly

Welcome to the next in our series of beginner articles. In this one, I’ll introduce the topic of how to use your gears.

Most bicycles in the USA these days have the chain shifting across several sprockets. Many earlier bikes, and some current ones, have actual gears inside the wheel hub, “internal gears”. We’ll discuss both kinds.

Why do bicycles have multiple gears? Multiple gears can make your riding smoother and less tiring, especially if you live in a hilly area, as well as in extremely windy situations.

The point of gears is to keep your pedaling effort and speed (“cadence”) at a comfortable level. Pay attention to your effort. If you are pushing down too hard, you need to go down to a lower (easier) gear. If you are spinning uselessly, you need to go up to a higher (harder) gear. CyclingSavvy Instructor John Allen demonstrates.

Just as with a car, low (easy) gears are for starting and moving slowly, and higher (harder) gears are to keep your engine — your legs — from turning too fast as you speed up. But there are important differences compared to shifting gears in a car.

Two shifters: what’s that about?

Many bikes have two or three front sprockets (called chainrings) at the cranks (pedals), and several sprockets on the rear wheel, giving you two shifters to think about. It would be simple if you had, say, a 21-speed bike with just one shifter that went from 1 to 21. But unfortunately, it isn’t that simple.

The good news is, using two shifters in combination is not as hard as you might think. Let’s say you have 3 chainrings (front sprockets, left shifter), and 7 in the back (right shifter, remember that both “rear” and “right” start with R). Don’t think of them as having 21 steps in a sequence (because they’re not): think instead of having 3 overlapping ranges of 7 steps each. Each chainring gives you a different range, and the rear sprockets let you make smaller adjustments within the current range.

• If you have 3 chainrings, think of the middle one as your “normal” range, where you will spend most of your time. Start and stop in this range, generally with the back sprockets at or near 1 (easiest). The smallest (inside) chainring shifts the whole range down to be  easier, for when you are going up a steep hill or into a strong headwind. The largest (outside) chainring shifts the whole range to be harder, useful downhill or with a strong wind at your back.

• If you only have 2 chainrings,  which one is “normal” will depend on you and on the specific gearing. Experiment.

• If you have just 1 chainring, the preceding 4 paragraphs don’t apply. :-)

You can feel how pedaling gets harder as you move a shifter one way, easier the other way.

Homing in on the range

One way or the other, once the range is right for the conditions, just shift your back sprockets as necessary. (Remember, rear = right shifter). Start from a stop at the easy end, or near it. As you gain speed, you will notice at some point that your pedaling is no longer delivering much power; then it’s time to shift up. This is usually all with the same front chainring.

The outermost of three chainrings (at the cranks) should be used only with the outer four or five rear sprockets, the inner chainring only with the two or three innermost rear sprockets. This essentially boils down to: avoid having the front in the easiest gear while the back is in relatively a hard gear, and vice-versa. Keep easy with easy, and hard with hard.

The middle chainring can be used with any unless the chain rubs against the outer chainring when used with the smallest rear sprockets. If there are only two chainrings, the outer one can be used with more of the rear sprockets.

Shifting gears strategy

Think “how do I shift to get to the gear I need to use,“ not “am I in 7th gear or 8th gear.” It would be complicated to keep track of the sequence from gear 1 to gear 21; also, many combinations are duplicates and near-duplicates, so it is pointless. Typically, a “21-speed” bicycle will have a working sequence of 10 to 12 different gears, and a wide enough range for any terrain and level of fitness, with small enough steps to be comfortable. Use the numbers on twist-grip shifters only as a guide — lower numbers, easier.

The basic sequence is to start in a low (easy) gear, and shift to a harder one when the pedals get to turning too fast. Keep pedaling lightly and shift down as you slow down. This will allow you to accelerate briskly from a stop or a low speed.

When accelerating from a stop, you may need to shift as often as once per second. This keeps your cadence in the sweet spot and accelerates you quickest. You have something in common with a big semitrailer truck — listen to it as it accelerates. The driver shifts through multiple gears, because the truck also has a narrow range of engine speed which optimizes power production.

Gear range wide enough?

Is your bicycle’s easiest gear easy enough? That depends on the terrain where you ride, and on your fitness. On most bicycles, it is possible to replace rear sprockets and widen the range. There is no shame in using an easy gear. It shows that you know how to take care of yourself.

No matter how many speeds your bicycle has in theory, you can use only one at a time! “21-speed” does make a nice advertising slogan, though, doesn’t it?

Derailer Complications

Most multi-gear bicycles in North America use derailers at the cranks and the rear wheel. Those mechanisms push (derail) the chain to one side or the other, from one sprocket or chainwheel to another. The derailer at the rear wheel has pulley wheels to take up slack in the chain produced by the different-sized sprockets. (Clever, right?)

A derailer system has some complications:

1. Shifting works only when the chain is moving forward! If you shift without pedaling, including when stopped, you will get a lot of grinding once you start pedaling, as the chain finds its way to the right spot. That is tough for the chain and sprockets, and embarrassing for you. If you did not shift down before stopping, the bicycle will be in a high gear and starting will be hard.
2. To shift smoothly as you slow down, keep spinning the pedals but without putting any force on them. When accelerating or holding speed, reduce force on the pedals momentarily as you shift.
3. You backpedal to step forward off the saddle when coming to a stop. (See our post about starting and stopping.) Finish shifting before you stop. If the chain and derailers are not aligned, the chain will jam as you backpedal. Test by backpedaling lightly. Sometimes you can adjust the shift levers even after stopping.

Internal Gears

Instead of a derailer, some bicycles have gears in the hub of the rear wheel, or sometimes at the cranks. Usually a shifter and cable connect to the internal mechanism; some two-speed hubs shift by backpedaling. 3-speed internal-gear hubs were very popular in the mid-20th century. Now 7 and 8-speed internal-gear hubs are common, and some have even more speeds.

An internal-gear hub shifts best when the chain is not moving, just the opposite of a derailer system. Coast or backpedal slightly for a moment while you shift. You don’t need to worry about downshifting while slowing to a stop; you can do that after you stop. It’s one less thing to concern yourself with. The sprocket can be changed with internal gears, in case you find that the range is too easy or too hard (usually, too hard). More about internal-gear hubs.

Shifting gears – Summary

Now that you know how shifting works, keep the goal of consistent cadence in mind as you ride. If your bicycle has more than one chainring, remember that the easy range is for uphill or headwind, hard one for downhill or tailwind. Middle (if you have 3) is for all other conditions. Use the sprockets at the rear wheel to adjust within the range as necessary. Easier gears are also good for creeping along while maintaining control, and being ready to accelerate, for example if a red light turns green before you reach it.

The idea is to keep your feet turning at a constant rate. A follow-up article will help you feel in your legs what that rate needs to be.