I have a dream bike. It's probably not what you think. My dream bike is pumpkin orange, has a svelte steel frame, priest-style handlebars, 700 c wheels, and 5 speeds. You can't buy it anywhere, and whenever I approach our otherwise fine mechanics, they tell me it can't be done, not with a traditional derailleur.
Why not?
Well, with a single chainring on the front, the chain will fall off. Unless you install a front derailleur. Plus, you can't buy a 5-speed cassette anymore. Anyway, why don't you just get a single-speed bike, they ask.
Cuz I like my knees, and sometimes, I want a little extra help.
Well, then, get a bike with an internally geared hub.
No. They're heavy and I don't like'em.
Without getting too much further into the actual feasibility of making my dream bike, and the pros and cons of internally geared hubs, let me just say that many cyclists are puzzled and frustrated by the number of gears on most standard bicycles available today. Here in Chicago, any number of gears above seven is completely redundant and unnecessary for most riders. It is a rare Chicago cyclist who has ever used all of his or her gears, and usually it was outside the state lines. Yet, not everyone wants a cruiser or a fixie. Some folks just want a basic hybrid to ride around town. Most bikes come factory-equipped with more gears than you can count on your fingers and toes, and few salespeople take the time to explain how to use them correctly. Consequently, many cyclist don't know how to shift gears for maximum benefit.
Surprisingly, when you purchase a 24- (or 21 or 27)-speed bike, you do not get gears 1 through 24. Instead, you get three ranges of eight gears. Here is how it works: most bikes have three front chainrings, attached to the pedal crank (road bikes generally have two chainrings): the small one is easy for climbing; the medium is moderate; and the large one is hard, for riding with wind on your back, or going downhill. These are operated by the front derailleur, controlled by the left shift-lever on your handlebars.
For each of the three chainrings, you get eight (or seven, or nine, depending
on your bike) gears from the cassette attached to the rear wheel. These
are operated by the rear derailleur, controlled by the right
shift-lever. Here, the smallest gear is the hardest,
and the largest is the easiest. This can be confusing, because it is the opposite of what happens with the front chainrings.
This arrangement of front and rear cogs gives you eight easy, eight moderate and eight hard gears. In a flat city like Chicago, you will probably be using primarily the moderate gear range. Most of us have a favorite gear or two in which we usually pedal. That's the gear that offers the most efficient cadence when you are moving at a good clip, but not pushing a gear that is too hard, or spinning in a gear that's too easy.
On a
derailleur-equipped bike (as opposed to a bike with internal gears housed inside a hub), you must be pedaling in order for the chain
to move to another gear. Many bikes have shifter indicators, telling
you what gear you are in. But after you've gained some practice, you
will be shifting gears by feel.
As a rule, shift gears when the riding conditions change: when changing
direction (the wind may now be in your face), when the road slope
changes, when you are forced to alter your speed. When you pull up to a
red light, shift to an easier gear (using your right shifter), so that
when the light turns green, you won't have to stand on the pedals to
get going. As you begin to accelerate, shift back up to your preferred
gear. Shift to an easy gear in front (the left shift-lever) when you
approach a steep incline (rare in Chicago, but it could happen, like
when you are going on an overpass), and keep shifting gradually as you
scale the hill and the pedaling gets harder. Once at the top, shift
back to the harder gear in front to get the most out of your descent.
Other things to remember:
- You don't really get 24 gears on your 24-speed bike, because some gear combinations are to be avoided. When riding in the small (easy) chainring in the front, avoid shifting to the small (hard) chainring in the rear. And vice versa. These positions cause the chain to cross over and subject it to undue stress. You may hear the chain grind as it rubs the front derailleur.
- Avoid shifting under torque. When you need to shift, ease the pressure on the pedals somewhat to release the tension in the chain, and allow it to move to the next cog as you press the shifter.
- You don't have to shift one gear at a time. Simply move through the range of gears until you get to the one you want, and the chain will follow.
Until I get my dream bike, which I promise to do every year, and invariably put it off when push comes to shove, I will keep using my old workhorse, wearing out the same three cogs on the freewheel.
From the Chicagoland Bicycle Federation comes this invitation to enter your workplace in this year's Bicycle Commuter Challenge:
