Chicago Bike Blog

Winter TLC for your bike

After you come indoors from a brisk winter ride, I know the last thing you want is to fuss with your bike. You want to warm you hands, have a nice  meal and perhaps a warming beverage. But at some point, perhaps after feeling returns to your fingertips, you'll have to attend to your bike. Snow and icy slush, especially  combined with salt and street grime, make a corrosive mixture that will eat through your bike and all its delicate systems.

To start off, use fenders. Not the kind that go on the seatpost. Real ones, front and back, that attach with struts and stay on. Like these:

They cost about $45 plus installation, but they will keep you and your bike drier and cleaner.

There is a some controversy about whether a bike should be stored indoors or out during winter. Without taking sides, I think it's safe to say that in Chicago you're usually better off storing your bike indoors to avoid theft. If you have the luxury of a porch, garage or basement, that's probably ideal. Otherwise, spread some absorbent matting in your  living room or hallway where your bike can drip dry. Storing your bike in a vertical position may help in draining any water stuck inside the cable housing.

If your ride has been particularly messy, brush off as much accumulated slush as you can before bringing the bike in, and rag off excess water. Lubricate the chain with an oil formulated for use on bicycle chains (not WD40).  Drip a little oil on each chainlink, and wipe off excess by running the chain through a rag with one hand while you slowly spin the pedals backwards with your free hand. Drip a little oil on the pivot points of both derailleurs (any hinge points at which the derailleurs flex), and a little more inside the jockey wheels on the rear derailleur. Do this at least weekly, and each time you ride through real slop. Following this ritual will protect your drivetrain from corrosion, excessive wear through the winter, and sudden breakage.

In winter, you should also regularly clean your bike, focusing especially on the drivetrain (the chain and everything it touches) and the wheels. This is also a good time to check your brakes. Pads can wear out a lot faster when exposed to salt and debris. If the pads get worn down to the metal, they will damage your rims (and fail to stop your bike). Keep the rims clean too, because this process can go both ways. Gritty stuff accumulated on the rims can speed up the wearing of the brake pads. Don't wash your bike at a carwash with pressurized water. That can knock grease out of bearings, and allow water to enter places it doesn't belong, like the rear freewheel or cassette, where it can later freeze causing all sorts of problems. Instead, use a bucket of hot soapy water, a rag and a stiff nylon bristled brush. Brush off the chain, all cogs and the rims of your bike. Dry everything thoroughly and re-lubricate as described above. (Find more winter bike maintenance tips at Chicago Bike Winter).

Rapid Transit Cycleshop does offer a winter tune-up package, where, for one set fee, we will take care of cleaning and maintaining your bike throughout the season. If you don't have the time, the space, the inclination, the patience or the ability to do it yourself, it just might be a great deal for you.

Thrift and the urban biker

Yes, I did. I rode down to the local thrift shop the other day to take advantage of their 50% off sale. Half off on second hand stuff that's already so cheap , it doesn't need to be on sale. But, hey, I love a bargain as much as the next person.

My bike, packed to the gills with thrift store finds.

So there I was, rummaging through the overstuffed racks, when it occurred to me that over the years, I've used a lot of stuff from thrift shops as my cycling gear. 
I don't mean the specialty gear stuff. Those things never get donated. It's so pricey, that, if it doesn't work, you return it to the place of purchase right away, so you can get your money back. And if it does work, boy, you hold on to it, cherish it, and get every last red cent of use out of it, and when it starts to fall apart, you see if you can get one more season out of it, and then build it a funeral pyre.
I certainly have some stuff that will be going on the funeral pyre at some, hopefully very distant, point in the future:

• Thin tights, made, oh, probably ten years ago by Hind. They are synthetic, but feel a little like wool. They are fantastic by themselves on mild days, but also work great as an underlayer when it's really cold.
• Any pair of Smartwool socks I have ever owned.
• Smartwool winter gloves. Amazing.
• Smartwool next-to-skin women's v-neck. Ditto.
• Powerstretch windfront tights made by Traverse Bay back in the days when they sold to bike shops (now they deal with the likes of Cabela and LLBean). The best tights for winter cycling. I'm pretty sure there is nothing like it on the market.
• Thin nylon over pants made by DeSoto, a triathalon company. They go over tights or ordinary pants to keep away the cold.
• Microfleece headband (fits under helmet).
• Swrve Milwaukee Hoodie. I just got it, but I think it will be on my funeral pile list for many years to come.
• Ecco Gore-Tex boots. Forget cycling shoes. I loosen the toe straps all the way, push my panniers back on the rack as far as they will go, and I wear those boots.

I hope you will forgive the digression. I realize the point of this post was to talk about all the great things for cycling you can find at a thrift store, not to brag about all the fantastic stuff I have. I just wanted to emphasize that some great stuff is worth the money, and you're wasting your time trying to find it used.
So, back to the racks. Can I find equivalents, or at least adequate substitutes for any of the items above? Let's give it a try:

• No luck on the thin tights. The only ones I found were cotton. Stay away from those.
• I'm funny about socks at thrift stores. But there were a bunch of Wigwam wool blend socks (50 cents on half-off day!) They were actually in decent shape, so I guess I would just wash them and give it a go.
• Gloves? Nothing here that even remotely compares to mine. But, there were a couple of pairs of very warm looking ski mittens (for two bucks, they are certainly worth the risk), and in the past, I have found a terrific pair of fully winterized leather motorcycle gloves. But you gotta look.
• Surprisingly, thrift stores have oodles of fine-gauge merino wool crewnecks and turtlenecks, both in the women's and men's department. They are great, low bulk, warm cycling layers. Check the label. The best ones are pure merino wool, but sometimes a blend is OK. Go for the thin ones. And for layering, head over to the vest department, and see if you can find a boiled wool or another tightly knit wool vest to layer over your torso. Keeping your torso warm helps to warm the extremities.
• Nothing like the windfront tights here. Any tights they have are pretty worn and gross. But there are some good, stretchy fleece pants. Go for them, if they're not too bulky, and you can turn them into a windfront garment by pairing them with the next item.
• A veritable treasure trove of thin nylon over pants. Take your pick. None seem to be more than $3, although there are some pretty arresting colors. That might be a good thing when you're on a bike. For the best emergency garment, choose ones that are super-light-weight and unlined.
• Headbands. Eh... Not too great. Most of them are too bulky for helmets. Buy one at the bike shop. They're not too expensive, anyway.
• Technical jackets? Forget it. You may find a light-weight windproof top similar to the pants for under five bucks. But if you want a warm, water resistant layer, go for the real thing.
• Yes, you can get decent boots here. It's just a matter of finding ones in your size. And you may need to shop before real cold weather hits.

And one other thing that I found: a backpack to schlep some of my stuff home in. I spent less than $40, and completely overstuffed my two grocery panniers, so I needed extra capacity. You can get a very decent urban backpack here. I got one with a mesh section and two temperature-controlled compartments for like a buck fifty. It will be perfect for my grocery hikes.
Anyway, that's what I found on my recent thrift shopping expedition. I'm curious if anyone has found anything in second hand stores that works really great for winter cycling. Let us know.
That's it for my bargain tips. Tomorrow, I may tell you how to spend money at Rapid Transit.

Rapid Transit Winter Biking Guide

"Will people still ride their bikes this winter?" I wondered.

I was driving back from Florida, and was filling up my rental car somewhere around Mt. Vernon, Illinois, where the marquee advertised gas at $1.99 per gallon. While it is unlikely that we will see gas prices like these in Chicago, it is undeniable, that, at least for the moment, they are going down. Before I returned my rental, I filled it up at $2.67, and later that afternoon, the same gas station posted a price of $2.58.
In case you haven't figured it out, high gas prices are great for the urban bicycle shop, like Rapid Transit. When they start falling, especially at the same time as mercury does, we worry.
A little.
Bicycle retailing is an emotional business. Two months ago, a line at our counter was several layers thick. Today, hours may go by before anyone enters the store. Is it the weather, or the price of gas?
More rationally speaking, we know from experience, that many people will continue to use their bikes without regard for the price of gas, and despite the weather.
Unlike fluctuating gas prices, winter weather cannot be disregarded by the winter cyclist in these latitudes. For you, brave souls, I have compiled what I hope is some useful winter cycling advice in one convenient spot: right here.

• Why ride in winter in the first place? 10 great reasons, courtesy of RocBike.
• Think it's cold here? Here's a kick you in the butt for you.
• Some winter riding essentials.
• What would your mother say? Advice on keeping warm. And some more.
• A story about winter riding hazards, and some other things (like tires).
• Tips on how to keep your bike in good shape this winter.
• If you're gonna ride your bike in Chicago this winter, you'll need service. This is it.

(Photo from Dingbat)

How to change a tube & tire on a bike

Before you begin changing a flat on your bike, you will need to remove the wheel from the frame. Click here for instructions on removing a wheel on a typical hybrid bike.

Chances are your tire has gone flat all the way. If not, unscrew the valve cap, and release any remaining air by pressing down on the valve core. If you have Schrader valves, press the valve core with a pointed object, as shown.

If you have Presta valves, loosen the tip of the valve, and press down on it with your finger. Then unscrew and remove the retaining ring from around the valve, as shown in the photos below.

You will now remove the tire from the rim. Begin by sliding one tire lever between the rim and the tire bead, with the curved end of the tire lever pointing down into the rim.

Repeat with a second tire lever, keeping the two levers 3-4 inches apart. Using the thumbs of both hands, flip the levers up and over, so that they are lying flat against the spokes, and the bead of the tire has been pried off the rim.

Secure one of the tire levers in place by hooking it around the nearest spoke, as shown.

Slide the other tire lever against the rim all the way around, until one bead is completely off the rim. If this is initially difficult, place the wheel vertically on the floor, and lean on the tire lever using the force of your entire arm. As more of the bead comes off the rim, it will become easier.

Pull the damaged tube completely out of the tire.

Some people advocate leaving the other bead on the tire on the rim. While this does make reinstalling the tire easier, I believe it does not allow you to thoroughly inspect the tire to identify the cause of the flat. Therefore, I recommend that you yank the tire completely off the rim, which should be fairly easy to do at this point.

Now take your pump or compressor, and begin filling the damaged tube to observe where the air is escaping. Inspect the tube, the inside and outside of the tire, and the inside of the rim to try to identify the cause of the puncture (click here for details).

Once you have identified and removed the cause of the puncture, you are ready to install the new tube. Put a little air inside the tube, just enough to give it shape, and insert it into the tire. A little air helps the tube stay put inside the tire.

Position the rim with the valve hole toward you. Lay the tire with the tube inside it on top of the rim, and insert the valve into the valve hole.

Go all the way around the rim, and insert only the bottom section of the tire bead into the rim. Do not start on the top section of the bead until the bottom part is mounted all the way around.

When you get to the end of the bottom section of the bead, you may find it easier to pry it into the rim using your tire lever. You may also wish to release some air from the tube at this point by pressing down on the valve core. This will reduce the tension on the tire.

Make sure one side of the tire bead is completely seated around the rim before proceeding to the other bead.

Begin pushing the top portion of the tire bead into the rim, starting at the valve.

Work the top bead in all the way around the rim using your thumbs or the heels of your hands. Some tires will go in fairly easily.

If yours does not, use the tire levers to get the last 3-4 inches of the bead seated, as shown.

(NOTE: Some tire and rim combinations make an extremely tight fit, and even a skilled mechanic has to struggle to get the tire properly mounted. If you find that to be the case with your bike, by all means, look into getting  a different set of tires that will allow you to change a flat with less difficulty.)

Before inflating the tire, make sure the tube is securely encased inside the tire, and not being pinched between the tire bead and rim at any point.

Inflate the tire to the recommended pressure (embossed on the tire sidewall), reinstall the wheel, and you are ready to roll!

Your flat repair kit

Getting a flat is pretty darn inconvenient. Don't make it any more so by leaving your flat changing essentials at home. Here is what you need to be able to change a flat anywhere:

• Spare tube. Make sure that it is the right size and valve type for your bicycle. Not all types of holes can be patched, and replacing a punctured tube with a brand new one is simply faster and more practical than patching a tube on the curb. You can patch the old one at home, if it is salvageable.
• Patch kit. Regardless of what I just said, you should carry patches. Occasionally, a brand new tube may leak air, or you may get a second flat because you haven't properly identified the cause of the original puncture.
• Tire levers. These are essential for removing the tire from the rim. Please don't use a screwdriver; it can damage not only the tube, but the tire and rim as well.
• Portable pump suitable for use with the type of valve you have. Usually, the smaller the pump, the longer it will take to fill up the tire, but even a very small pump is better than nothing.
• A wrench, if your bike does not come with quick release wheels. Generally, 14 and 15 mm wrenches are needed loosen nuts on front and rear wheels, but an adjustable wrench will do in a pinch.
• Just in case: cell phone and money. Carry those whenever you are more than walking distance from home.

Most importantly, practice changing a flat before you leave home. If you come to Rapid Transit to have your flat fixed during non-peak hours, we often have time to show you how it's done. But it is usually not enough to be shown: you have to practice it yourself.

Coming up: step-by -step tube changing tutorial.

Dealing with flats

I was going to tell you how to change a flat on a bike.
Nothing could be simpler. It takes,  oh, maybe ten minutes.
And then again, if you've never done it before, it could take over an hour.

This lesson was brought home to us, seasoned flat-repairers, recently as Rapid Transit Cycleshop hosted a flat-fixing workshop for some friends and their kids. We were again reminded that before you can teach someone how to fix a flat, there is a whole bunch of other stuff they should know first.
So instead of one post, we'll do a series.
Click on links below for information on:
The anatomy of a bicycle wheel
What causes flats
Types of valves
Your flat-repair kit
Removing and reinstalling the tire and tube

What causes flats?

Have you ever been plagued by recurring flats? You keep fixing the tube, or taking it back to your bike shop, you ride for awhile, and, boom! It goes flat again.

A pile of tubes looms over a mechanic's bench at Rapid Transit, waiting for be recycled.

Let me just say that yes, there are mystery flats. There probably is a cause for them, but it cannot be reasonably identified by either you or the mechanic(s). However, in most cases, people continue to get recurring flats, because the the thing that caused the original flat has not been correctly identified.
When you pull your punctured tube out of the tire, go ahead and overinflate it using your pump or an air compressor, and find the hole where the air is escaping.

Look closely at that hole. Where on the tube is it located: top, side, bottom or at the valve? Is it a single hole, or a double? Is it a tear?
Let's begin by identifying five major types of flats, and we'll go over them and their probable causes in more detail:

1. Outer surface punctures
2. Sidewall punctures or "snakebites"
3. Inner surface punctures
4. Blow outs
5. Valve problems

Outer surface punctures:
As you look at your overinflated tube, you will see a single hole on the outer surface of the tube (the surface that corresponds to to the part of the tire that rolls along the ground). That indicates that a sharp object penetrated the tire and punctured the tube. The object may have fallen out, but just as likely, it is still embedded in the tire. Before replacing the inner tube, run your fingers very carefully along the inside of the tire, feeling for anything sharp that may be protruding. At the same time, examine the outside of the tire for embedded pieces of glass and other debris, and poke them out as you go along (a paper clip or sharp tweezers work well). If your tire feels thin and flimsy, or has a lot of slits from previous contact with glass, consider replacing it with a puncture-resistant tire.

Sidewall punctures:
All tires have their recommended inflation pressure embossed on the sidewall. That number can seem incredibly high, especially if you are used to filling up car tires. Bicycle tires take much higher pressure than any car tire, and generally, the thinner the tire, the higher the recommended pressure. Many people are reluctant to fill their bike tires to recommended pressure, perhaps because they are afraid of blow-ups. As you increase the amount of air in the tire, it gets harder and harder to pump, which can make you feel like you're overdoing it.  Yet, filling up tires to the correct pressure will protect you against one of the most common types of flats: the snakebite.

The cause of this is most often riding on underinflated tires. When you hit a bump in the road, the lower-than-recommended pressure allows the tire to bottom-out against the sharp edge of the rim, and the inner tube becomes pinched in the process. You will recognize a snakebite if  you examine your overinflated tube, and discover two small holes, about 1/4" apart, usually on the side of the inner tube.

Inner surface punctures:
If your overinflated inner tube is losing air from its inner surface (the surface that would have been facing the rim), you will need to examine the inside of the rim, and the tire beads. Typical causes of this type of puncture include: a faulty rim strip, resulting in exposed spoke nipples or sharp rim surfaces, a burr on the inner seam of the rim, or a broken tire bead, with exposed wires digging into the tube.

Blow outs:
Sudden blow outs happen when the tube, instead of being safely encased inside the tire, becomes exposed to the outside world. This can happen if, when changing a flat, or filling the tire, a piece of tube inadvertently gets pinched between the rim and the tire. Sometimes it blows right away, but not always. Similarly, you can get a blow-out is the tire bead isn't correctly seated inside the rim, and the inner tube begins to protrude out. Generally, you will feel thumping for the short distance you may be able to ride.

Blow-outs can also occur when the integrity of the tire becomes compromised, and the tube starts to protrude. This can happen as a result of dry rot, a brake pad, fender or other mis-adjusted part rubbing over the tire, or the bead separating from the tire. Inspect your tires periodically to make sure they are in good condition.

Valve problems:
Occasionally, small amounts of debris get jammed inside the valve, causing it to be stuck in open position and leak air. If used improperly, certain flat-prevention products can have the same effect.

Another type of valve failure can occur when you ride on underinflated tires. Every time you brake, the tube and tire continue to move just a little bit even as your wheel stops. This causes the valve to come through the rim hole at an angle. If this goes on long enough, the valve an separate from the body of the tube at the base.

The anatomy of a bicycle wheel

The majority of bicycle wheels you are likely to encounter are comprised of four parts:

1. The tire.
2. The inner tube.
3. The wheel itself, which includes the hub, spokes and rim. For the purposes of flat repair, we will be talking primarily about the rim.
4. The rim strip.

Let's look at each in more detail:

Tire:
The tire is the firm rubber casing mounted on the rim of the bike. By itself, the tire is incapable of holding air. It is open in the center, and has two rigid and fairly sharp edges that allow it to be mounted onto the rim.

These edges are called "beads". On the majority of wheels, the beads are made of coils of wire encased in protective rubber.
As you ride, the tire rolls over road debris, and may pick up pieces of glass, nails and other sharp objects. Some of these items will penetrate the wall of the tire. Most of these punctures are tiny, and do little or no damage to the tire. The tire does need to be replaced if it develops a gash or tear, has dry rot or cracks along the side, or if there is evidence that the bead is separating from the main body of the tire, or protruding from the rubber casing.
The reason small tire punctures become problematic, is that most often they penetrate through to the inner tube, and cause it to lose air.

Inner tube:
The inner tube is a soft, pliable rubber donut with an air valve on its underbelly that allows air in and out.

Note that a filled inner tube can appear larger than the tire. This is perfectly normal. When encased inside the tire, the tube will not exceed the tire's dimensions. When the tube develops a hole for any reason, it will lose air, and need to be patched or replaced.

Rim:
There are many different types of bicycle rims. In addition to the important function of holding the tire onto the wheel, the rim also serves as the anchor for spoke heads, or nipples. On some rims, spoke nipples rest directly on the inner surface of the rim that comes in contact with the inner tube.

On other types of rims, an extra metal layer separates the spoke nipples from the inner-tube. This metal layer has holes drilled in it for access to the spoke nipples. In either case, the protruding spoke heads, or the edges of the holes drilled in the rim are sharp, and can cause damage to the inner-tube.

Rim strip
To prevent this from happening, the inside of the rim is lined with a rim strip. This can be a snug-fitting rubber strip, or pre-gummed cotton tape that is applied to the rim surface. To do its job, the rim strip has to go all the way around the rim , and cover all the spoke heads or holes (except the valve hole).

If it becomes, torn, worn, or folded over, it is no longer doing the job of protecting you from flats.
Please note that on many brand new bikes, cheap plastic rim strips are often used, which can themselves cause punctures and flats (click here for more).

How do you get the dang wheel out?!

This is the front brake setup on a typical hybrid:

To get the front wheel out, you will first have to release this brake. The brake cable is housed in a metal casing called the "noodle", with a cable stop, which falls into a slot on a little swing arm attached to the main brake arm:

To release the brakes, you will need to squeeze the brake arms together, and lift up on the noodle to remove the cable stop from the slot. I find it easiest to push the brakes together with the heels of my hands while I manipulate the cable with my fingers. If you have larger hands, you may be able to squeeze the brakes together with one hand, and pull the cable with the other.

Voila! Now the brake arms can swing open:

Next, move down to the wheel hub to open the quick release lever which retains your front wheel:

Grasp the underside of the quick release lever, and open it by swinging it out:

On the opposite side of the hub, turn the nut a few turns to get it past the "lawyer knobs" designed to give your front wheel a little extra security:

You can now pull the wheel out, and lay your bike down, or rest it on the fork.

A few things to remember when you are reinstalling the front wheel:

1. Do not overtighten the nut on the front hub. It should be just tight enough to allow you to close the quick release lever applying a reasonable amount of firm pressure with the palm of your hand, as shown. (click here for details.) The lever should leave an imprint on the palm of your hand.

2. Reattach the brakes by reversing the steps above. As a final step, lift up on the handlebars and spin the front wheel to see if it is spinning freely. If not, don't panic! Without unhooking the brakes, flip open the quick release lever. This will allow you enough wiggle room to center the rim between the brake pads.

Now, close the quick release, and test the wheel again. Don't get frustrated. It may take a couple of tries if you've never done this before.

(The same guidelines apply to removing the rear wheel, however the procedure is somewhat more complicated by the presence of the chain. We find it easiest to start by shifting the rear (right) shift lever until the chain drops to the smallest cog. Then, pretty much follow the above procedure. I will do a post with complete guidelines in the near future.)

How to use your 24 gears

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.