Bike Repair & Maintenance For Dummies®

by Dennis Bailey

  3. Pull the lever down so that the bead rises up and over the rim.

  4. Hook the bottom of the lever to a spoke to keep it in place.

  Some tires are very tight and you’ll need extra room, so don’t hook the first tire lever to the spoke until you get the second lever slid under the tire.

  5. A few inches away, repeat steps 2 and 3 with the second tire lever.

  6. Repeat steps 2 and 3 with the third lever, but instead of hooking the lever to a spoke, start dragging the lever around the wheel away from the first and second levers (as shown in Figure 6-2).

  You should notice the tire becoming looser until the entire side pops off the rim.

  Figure 6-2: Using tire levers to remove the tire.

  7. Before removing the inner tube from the wheel, pump it up with a little extra air. Later, when you have to look for the puncture, you’ll need some air in the tube and it’s easier to pump up the tube while it is still on the wheel.

  8. While the tire is still on the rim, reach under it and pull out the tube.

  9. When you reach the valve, lift up the tire and pull the valve through the rim, being careful not to damage it.

  Note the position of the tube in relation to the tire so when you find the hole in the tube it will be easier to locate the cause (glass, a nail, a thorn), if it’s still embedded in the tire.

  Finding the puncture

  You’ll need to do a little detective work to find the puncture. To track down the source of the problem, follow these steps:

  1. Examine the inner tube by listening for a leak.

  If it doesn’t have air, pump it up to a larger shape than round. With the additional air pressure, the leak may make a hissing sound as the air tries to escape.

  2. If you’re having trouble listening for the leak, float your finger above the surface of the inner tube until you feel the flow of air escaping.

  If you’ve narrowed the source of the leak to a small area, but you still can’t find the actual hole, apply a small amount of saliva to the tube. Bubbles will lead you to the source.

  If you don’t want to gross out your riding partners by spitting on your tube, you can sometimes find a very small hole or slow leak by holding the tube near your lips. The lips are very sensitive and should feel the smallest amounts of air leaking out.

  3. If you’re still having trouble finding the leak, submerge the tube under water.

  A stream of bubbles will be clearly evident after submerging the tube. When you remove the tube from the water, wrap it around your finger at the source of the leak or mark it so that you don’t lose the location.

  In some cases, a hard-to-find leak may be traced to a valve problem. This is one situation in which you may want to employ the saliva technique. Apply a few drops of saliva to the end of the valve to look for signs of air escaping. For a Schrader valve, you can try tightening the valve core. If this doesn’t work, you may need to remove the core, put a few drops of oil on the spring, and reinstall the core. This technique requires a valve cap with a built-in valve core tool or a separate valve core tool, something you can buy at bike shop. If the leak is coming from a cracked or cut stem, you’ll have to replace the tube. In the case of Presta valves, more likely than a leak is the valve breaking (because valves are fragile).

  Valve leaks are hard to find when the tube is outside the tire because the tube usually has very little air pressure and leaks in the valve usually only show up when there is a lot of air pressure (that is, when the tube is sitting inside the tire and the tire is inflated to the proper air pressure).

  Patching the tube

  After you’ve identified the source of the leak (see the preceding section), follow these steps to patch the tube:

  1. Lay the tube on a flat surface.

  2. Using the abrasive paper or metal scraper included in your puncture repair kit, rough up the area around the puncture (as shown in Figure 6-3).

  The goal is to remove any dirt or debris from the surface and help the patch bond to the tube.

  Figure 6-3: Roughing up the tube.

  3. Coat the tube with a thin, even layer of glue from the puncture repair kit in an area centered over the puncture and slightly larger than the size of the patch (as shown in Figure 6-4).

  Allow the glue to dry completely before proceeding.

  4. Remove the metal backing from the patch (leaving the side covered in cellophane alone).

  Avoid touching the sticky side of the patch during this process. Doing so can weaken the patch’s bonding properties.

  Figure 6-4: Applying glue to the tube.

  5. Apply the patch to the tube, making sure to center it over the puncture (as shown in Figure 6-5).

  Figure 6-5: Pressing the patch onto the tube.

  6. Press the patch firmly and repeatedly in place and, using a tire lever, smooth it out to remove any trapped air.

  Leave the cellophane in place — it prevents the glue from sticking to the tire.

  If you’re using glue-free patches, you’ll rough up the tube as in Step 2 and apply the patch directly after removing the backing.

  Glue-free patches are designed to provide a quick fix to get you home and are not the long-term solution that the standard glue type patches can be.

  Inspecting the tire

  After successfully patching or replacing the tube, you’ll want to inspect the tire to make sure that there aren’t any sharp objects in it which could re-puncture the tube. Here’s how:

  1. Drag a rag or a biking glove along the inside of the tire, in both directions, to determine if there is anything lodged in the tire.

  Always drag the rag of the glove in both directions through the inside of the tire. Sometimes the object is at an angle and won’t be detected until it’s wiped in the opposite direction.

  2. Visually inspect the inside and outside of the tire, looking for any objects wedged inside the tread or cut into the sidewall.

  When it’s more than just a flat

  When you inspect the tire after repairing the tube, pay attention to any tears or rips in the tires. Whatever punctured your tube may have caused damage to the structural integrity of the tire.

  If the tire has a tear, inflating the newly installed tube or riding on it may cause the tube to explode through the hole in the tire, giving you a startle that packs more punch than a double espresso.

  If your tire has any structural damage, you can use a tire boot (a temporary patch for tires) to get home. You insert the tire boot between the tube and the tire, and the boot prevents the tube from expanding through the opening in the tire. Some boots can be fastened to the inside of the tire by adhesive backing, and others are designed to be held in place by the pressure of the tube pushing against the inside of the tire wall.

  Although a boot will enable you to ride on a damaged tire, it’s meant to be temporary, helping you to get home or to a place where you can replace the tire.

  To patch a tire with a boot, peel off the backing and adhere the boot to the inside of the tire where the tear or cut is located. If the boot doesn’t have adhesive, you have to wrap the boot around the slightly inflated tube at the location of the damage, knowing that, after the tube is fully inflated, the boot will be held in place.

  In an emergency, you can use a dollar bill the same way you would a tire boot. Dollar bills are surprisingly strong. Dennis always keeps at lease one in his seat bag.

  Ready to Roll!

  At this point, you should have a patched or replaced tube, a tire free of debris, and the enthusiasm of knowing that this pit stop is just about over. After you finish the final steps of putting the tire and tube back on the wheel, inflating the tube, and the attaching the wheel to the bike, you’re ready to roll! We cover these final steps in this section.

  Putting on the tube and tire

  To reinstall the tube and the tire on the wheel, follow these steps:

  1. Position the wheel with the valve hole facing upward.

  2. Pull back the tire an
d insert the valve of the tube, partially inflated (enough to give it its shape), into the hole.

  3. Working your way around the tire, tuck the tube up into the tire and on the rim being careful not to twist it.

  4. Pinch together the sides of the tire in order to lift the other half of the tire bead onto the rim.

  Try to use your hands to put the tire on the rim. Using the tire levers could re-puncture the tube you just worked so hard to repair or replace.

  When you finish this step half of the tire should be pushed over the rim.

  5. Start with the valve in the bottom, or 6 o’clock position, and begin working your hands away from each other around the wheel and pushing down on the bead with your thumbs or other fingers.

  6. When your hands get closer together at the top, or the 12 o’clock position, squeeze with as much force as you can muster.

  You should be able to pop the final portion of the bead into place (as shown in Figure 6-6).

  Figure 6-6: Putting the tire back on the rim.

  Sometimes the tire is very tight when you get near the top. If this happens, you need to let all the air back out of the tube and start again with your hands at the bottom, or 6 o’clock position, making sure the tire is seated down inside the lip of the rim. Pull the last section of tread with your palms. Rotate the wheel and, from the back, use both hands to pull up repeatedly until the bead snaps in.

  If you must use a tire lever for the last step, be careful not to pinch the tube against the rim, or you could be back to square one. Either way, it’s time to put a smile on your face. You’re almost finished and everything is downhill from here.

  Inspect the tire to make sure that the tube is not sticking out from under it. As a precautionary step, push the valve up into the tire to make sure that the part of the tube surrounding the value is not pinned against the rim and then pull it back down to inflate. If everything looks good, begin to inflate the tube according to the pounds per square inch (PSI) rating, marked on the sidewall of the tire. As you pump it up, examine the tire to make sure the tube is expanding consistently within the tire and isn’t bulging in any areas. If the tube isn’t expanding consistently or is bulging, the tube may be twisted or pinched by the tire and need to be reinstalled.

  Attaching the wheel

  To attach the wheel, follow these simple steps:

  1. Confirm that the brakes have been released and there is space for the wheel to pass between them.

  2. If you’re attaching the front wheel, position the wheel hub within the frame’s fork and slide it into place.

  If you have a quick-release hub, the quick release will be loose in the open position. It starts to get snug when the lever is pointed straight out away from the bicycle, and very tight when pivoted into the closed position. You can adjust the tension for the closed position with the hand-turn nut on the opposite end of the quick-release skewer.

  Never use the lever as a wing nut and crank it to tighten the quick release. Doing so won’t result in sufficient force to hold the wheel to the fork. The lever must be closed for the cam mechanism to securely clamp down on the fork.

  If you don’t have a quick release, begin by tightening the axle nuts on both sides of the hub a little at a time until both are securely in place.

  3. If you’re attaching the rear wheel, make sure the right-hand shifter is placed into the highest gear, the gear that moves the chain farthest away from the bike and onto the smallest cog.

  4. Maneuver the wheel into place so that the top part of the chain just above the derailleur falls onto the smallest sprocket.

  To facilitate this step, push the derailleur arm down and pull the cogs in between the loop.

  5. With the chain sitting on the smallest cog (which is the cog it was on when you removed the wheel), slide the wheel into place into the rear dropout part of the frame.

  6. Use the instructions in Step 2 to fasten the quick release or the axle nuts.

  Congratulations! Your tire and tube should be in good shape and your flat tire a soon-to-be distant memory. After doing this a few times, you’ll find that fixing a flat will be little more than a five- to ten-minute pit stop that will barely give your riding partner time to return from a restroom break.

  Coming to a screeching halt: When you get another flat right away

  For those of us who have had the excruciatingly frustrating experience of getting a flat five minutes after repairing the first one, we know there are many more descriptive and colorful words come to mind than our publisher will let us print in this book.

  If a flat tire strikes twice consider the possible causes:

  More than one puncture is in the tube and you only patched one of them.

  A shard of glass or some sharp object is hidden in the tire and has re-punctured the tube.

  When you reinstalled the tube, part of it was pinched between the rim and the tire.

  The solution is to take a deep breath and repeat the process, being extra vigilant when finding the puncture, inspecting the tire, and installing the tube.

  Of course, there is always the chance that you did everything perfectly the first time and it just so happened that you had the incredibly bad luck of running into a second sharp object on the road. The good thing is that, over time, the odds even out, and the next time you’ll be the one taking the bathroom break while your riding partner is on her knees with tube in hand.

  A Pound of Cure: Preventing a Flat

  The obvious choice of any bike rider is to avoid flats. Although this might be impossible for any wheel system that uses tubes, prevention is the next best option. To help prevent flat tires, proper maintenance is key:

  Keep your tires inflated to the proper pressure as indicated on the side of the tire.

  Replace tires at the first sign of worn tread or deteriorating sidewalls.

  Replace tubes that have already been patched more than a dozen times.

  Inspect tire tread for objects stuck in the tread that may cause a puncture.

  If you’re willing to spend a little extra money to prevent punctures, consider investing in Kevlar-reinforced tires. The composite fibers that make up Kevlar are strong enough to resist punctures that would normally occur from contact with sharp objects. Kevlar tires typically run about $15 to $20 more than regular tires.

  If Kevlar tires aren’t in your budget, try tire liners, which are made of strong, lightweight fibers and line the inside of the tire to provide extra protection to the tube. Other options are thorn-resistant tubes and tubes with flat sealant that fills small holes from the inside without the rider even knowing he’s had a puncture.

  Even if you take all the preventive steps mentioned in this section, you’re still likely to get an occasional flat. Once, on a trip from Ireland to Italy with a heavily loaded bike, Dennis went three months without a single flat. A few months later, on a trip in the United States, he was pulling his hair out on the side of the road after five flats in one week. Go figure!

  If you keep a patch kit, tire levers, pump, and spare tube with you while you bike and you practice the steps described in this chapter, the chances are good that you’ll be able to fix a flat and be back on your bike quicker than your partner can finish off a PowerBar. This will give you the confidence to take long, worry-free bike rides and save you from the embarrassment of having to ask another biker to show you how to change a flat or from walking your bike home.

  Chapter 7

  Hugging the Curb: The Wheels

  In This Chapter

  Buying the right wheels for your bike

  Caring for and inspecting your wheels

  Removing and installing wheels

  Working on hubs

  Truing a wheel and working on spokes

  You can’t think about caring for your bike without making the wheels a big part of the plan. Wheels that spin straight, round, true, and smooth, on properly inflated tires, greatly contribute to the comfort of a bike ride. Wheels that run rough on tires inflated
to the wrong level can, at the very least, take the fun out of a ride and, at worst, be downright dangerous.

  In this chapter, we fill you in on the basics of maintaining and repairing the wheels of your bike. Here, you find out how to inspect your wheels to make sure they’re in good working order. If your wheels aren’t working properly, we give you steps to take to repair them, including overhauling the hubs and truing the spokes.

  The Spin on Wheels

  If wheels are made of quality material, are built with properly tensioned spokes, and use tires inflated to the correct pounds per square inch (PSI), they should last a long time and not need repair or service other than keeping the hubs lubrications and in good working condition.

  In this section, we fill you in on how to care for your wheels, keep them in good working order, and handle problems if they arise. We also give you the skinny on shopping for new wheels, in case you need to replace one.

  Shopping for new wheels

  Wheels are measured according to their diameter and width. If you’re shopping for wheels, you might see a number like 700C x 19. The first number is the diameter of the wheel in millimeters; the second is the width.

  Sometimes manufacturers uses the English-American standard and list the numbers in inches (for example, 26 x 1.9). In other cases, manufacturers write one number in inches and the other in millimeters (for example, 26 x 19).

  Knowing the size of a wheel is important because not all wheels will fit a bike and not all tires will fit a wheel. The diameter determines what wheel will work with your bike. The forks on a bike are designed to use wheels of a certain size. If the diameter is too large, the wheel won’t fit on the bike. If the diameter is too small, the brakes won’t align properly with the rim.

  The width impacts the tires you can use. Wider rims are usually found on mountain bikes, which use thick tires with heavier tread. Narrower rims are found on road bikes, which use thin tires.