Bike Repair & Maintenance For Dummies®

by Dennis Bailey

  There are a number of telltale signs that you have an issue with your chain:

  You have to exaggerate the movement of your shifter to force the chain to jump to another cog on the rear wheel.

  The pedal jerks forward when you’re applying pressure, because the chain skipped a tooth on a cog.

  Pedaling is not as smooth as it once was.

  The chain makes a lot of noise while you pedal but not while you coast.

  Issues with your chain can be caused by a number of factors. The most common of them are dirt, stiff links, and normal wear and tear.

  Getting down and dirty

  The chain is one of the parts of your bike that’s completely exposed to the elements. This, combined with the fact that it has to be covered in lubrication to work properly, makes the chain a magnet for dirt and grime.

  The abrasive qualities of dirt begin to wear down the chain and the other parts that the chain comes in contact with, such as the cogs, chainrings, and rear derailleur pulley wheels. When dirt works its way into the chain links, they become stiff, which hampers your bike’s shifting ability (see the following section).

  Stuck in a rut: Stiff links

  If you find that your chain is skipping or making a consistent, repetitive noise when you’re pedaling, you may have a stiff link. To find a stiff link, follow these steps:

  1. Shift the chain onto the smallest cog.

  This puts the most bend in the chain and causes the stiff link to be more apparent.

  2. Slowly rotate the pedals backward, keeping your eye on the chain and the rear derailleur.

  If the chain has difficulty moving through the pulley wheels at one point, you’ve likely got a stiff link.

  Stiff links are sometimes caused by a lack of lubrication. The other possibility is that, when the chain was connected, the chain plates in the link were compressed tightly together, making it difficult for the link to pivot.

  To take care of a stiff link, first try lubricating the rollers that sit inside the offending link. Give the lubrication a little time to work its way down into the joint and then, while holding each side of the link (use a rag if you don’t want to be covered in grease), pivot the link up and down to try to loosen it.

  If lubrication doesn’t solve the problem, try flexing the chain back and forth by pushing inward with your thumbs and twisting outward with your hands to work it free, as shown in Figure 10-4. Reverse the position by pushing inward with your thumbs on the other side of the chain a few times. This should be enough to restore flexibility to the chain.

  Figure 10-4: Loosening a stiff chain.

  Sometimes with a stiff chain, you’ll notice that a rivet is sticking out to one side more than the other rivets are. In this case, you’ll need to use a chain tool to push it back in. Put the chain in the chain tool and turn the handle just a small amount, maybe one-eighth of a turn. If the link is still tight, try repeating the procedure from the other side, rotating until it loosens up.

  Some chain tools have two slots, or cradles, where you can rest the chain (see Figure 10-5). The slot farthest away from the handle is the primary cradle and is used for breaking and connecting chains. The other cradle is specifically designed for tight links, so make sure you use this one.

  Figure 10-5: Cradles in a chain tool.

  Wear and tear

  Although keeping your chain clean and lubricated will greatly extend its life, normal use of the chain will eventually lead to wear. The chain does most of the work, transferring power to the rear wheel, revolution after revolution. After you’ve traveled enough miles, it begins to stretch, and after it starts stretching, it can rapidly wear out the chainrings and cogs. A stretched chain is also more vulnerable to breaking.

  Stretching doesn’t mean that the chain links have increased in size. It just means that, over time, the wear on the rivets, rollers, and inner links increases the amount of play at each link. The accumulated looseness across many links causes a stretching effect.

  The best strategy is to be proactive and frequently inspect the chain for wear, at least during your monthly maintenance check.

  The simplest way to check for chain wear is to measure the chain. To measure the chain, use a ruler and measure from pin center to pin center as is shown in Figure 10-6. Twelve paired links of a chain should measure 12 inches from pin center to pin center. A slightly longer length means that the chain has stretched.

  Some companies offer chain measuring tools (see Figure 10-7) that are easy to use. If both ends of the tools set down inside the chain, the chain is the appropriate length.

  Chains wear out at a faster rate than chainrings and cogs. If you determine early enough that your chain has started to wear or stretch, you can replace only the chain, which will save you a lot of money. If you’re really on top of things, you may go through two or three chains before you have to replace the more expensive chainrings and cogs.

  If your chain is skipping when you apply force when pedaling, it may be due to worn teeth on the freewheel, cassette cogs, or chainring. Examine both and replace them as needed. (See Chapter 11 for more information on caring for cogs and Chapter 13 for chainrings.)

  Figure 10-6: Measuring a chain the old-fashioned way, with a ruler.

  Figure 10-7: A chain measuring tool makes measuring a chain easy.

  If you determine that the chain needs replacing, inspect the chainrings and cogs for wear. If the teeth on a cog or chainring are no longer symmetrical and look like an ocean wave or as though they’ve been filed down on one side (as shown in Figure 10-8), it’s time to replace the part. Another sign of tooth wear is the chain skipping when you pedal with a lot of force.

  Figure 10-8: Worn teeth on a cog or chainring should be replaced.

  Sometimes only one cog will wear out. This is usually the cog that corresponds with the gear you use most when riding. If this is the case, you can replace just the cog and not the entire cassette, although sometimes it’s cheaper to buy a cassette than a set of replacement cogs. More often, you’ll end up replacing a single chainring and an entire cassette.

  Caring for Your Chain

  A bike’s chain is one of the most important parts of the bike to keep clean. It attracts dirt and grime because it is exposed on the bottom of your bike where it is close to the ground. Because it comes into contact with other parts of the bike, such as the derailleurs, it can spread dirt around your bike causing parts to wear out prematurely. Our best advice is to give the chain a simple cleaning each time you ride and then, once a month, give it a deeper cleaning.

  Every time you ride, you should give your chain a simple cleaning and lubrication. And at least once a month, you should give it a deeper cleaning. In the following sections, we cover both types of cleaning.

  It is best to clean the chain while it is on the bike unless it is extremely dirty or it has been a long time since you have cleaned it.

  Put the chain on the smallest sprocket before cleaning. This will expand it slightly and expose the pivoting points of the chain to allow degreaser and lubrication to work its way inside the links.

  If the chain has a lot of mud or dirt caked on, rinse it off with water before beginning.

  Clean the pulley wheels of the derailleur, chainrings, and cogs if they are dirty. You don’t want to undo all your hard work by running a newly cleaned chain across any other filthy components.

  Keeping it simple: Cleaning and lubricating your chain

  If you only have a few minutes and your chain is not overly dirty, all you need to clean your chain is a rag and a bottle of lube. (See the nearby sidebar, “Bike lubricants out the wazoo,” for more on different types of lubrication.)

  Bike lubricants out the wazoo

  When you’re shopping for lubricants, the first step is to make sure you get one formulated for bikes (as opposed to something that’s all-purpose, or meant for motorcycle chains, chainsaws, or car engines).

  After you’ve narrowed down the possibilities to the lubes meant fo
r bikes, your next choice will likely be dry (meaning, they pick up less dirt) or wet (meaning, they’re harder to wash away in wet conditions). Unless you’re going to be riding in wet conditions or crossing streams, we recommend sticking to a dry lubricant.

  You may also see wax-based lubes — these are dry lubes that attract the least amount of dirt and grime and will keep your chain looking clean. But they need frequent application because they don’t last long, especially in wet conditions. Also, they work best when they’re applied or bonded to a chain that has been completely degreased. Unless you’re willing to commit to frequent applications of lubrication, we recommend against wax-based lubes.

  Lubricants are sold in aerosol spray cans and squeeze bottles. Many riders prefer squeeze bottles because they can control the flow, applying lubrication drop by drop. With a spray can, it’s too easy to get lubrication where you don’t need it (such as on the outside of the chain) or where you definitely don’t want it (such as on wheel rims).

  Some manufacturers recommend that when you start with a lubricant you stick with it, and not change horses midstream. Regular cleaning and lubrication of your chain is probably more important than whether you mix lubricants, but if you’re finicky about your bike, sticking with one lubricant doesn’t hurt.

  Remember: New chains are lubricated by the manufacturer before they’re shipped. The quality of this straight-from-the-manufacturer lubrication is better than what you can achieve with a store-bought lube. Under normal riding conditions, you should be able to get several hundred miles with a new chain before you need to apply lubrication.

  Here’s how to give your chain a simple cleaning and lubrication:

  1. With a clean rag, grab the chain on the bottom, between the lower derailleur jockey wheel and the bottom of the chainring.

  2. Rotate the pedals in reverse to move the chain through the rag.

  3. After you’ve wiped down the chain, apply lubrication to the top of the lower rung of the chain, where it exits from the rear derailleur, using a spray can or squeeze bottle.

  4. Rotate the pedals in reverse to move the chain as you lube it, completing ten revolutions of the chain to make sure you haven’t missed any links.

  You don’t need to douse the entire chain in lubricant. The goal is for the lubrication to work its way into the rollers inside the chain. There’s no need for the outer links to be covered in lubricant.

  5. Wipe off any excess lubrication using a clean rag, as shown in Figure 10-9.

  Figure 10-9: Wiping excess lubrication off the chain.

  6. With a clean rag, grab the chain on the bottom, between the lower derailleur jockey wheel and the bottom of the chainring.

  7. Rotate the pedals in reverse to move the chain through the rag, and do this for several full revolutions.

  Going deeper: Giving your chain a heavy-duty cleaning

  You should give your chain a deeper cleaning at least once a month — more often depending on the conditions you ride in. With a deeper cleaning, you still leave the chain on the bike (see the preceding section) — the difference is, you first use a degreaser to remove any remaining, broken-down lubrication. You also give the chain a more rigorous cleaning by using a brush or a special chain scrubbing tool.

  Most bike shops sell a chain cleaning tool (see Figure 10-10) that has a plastic housing that immerses a chain in degreaser while internal brushes scrub the chain links. This tool gives the chain a much deeper cleaning than you can accomplish with a rag or even a handheld brush.

  To give your chain a deep cleaning by hand, follow these steps:

  1. With a clean rag, grab the chain on the bottom, between the lower derailleur jockey wheel and the bottom of the chainring.

  Figure 10-10: A chain cleaning tool takes your cleaning to the next level.

  2. Rotate the pedals in reverse to move the chain through the rag.

  3. Drench a rag in degreaser, lightly grab the chain with the rag, and rotate the pedals in reverse to apply the degreaser to the chain.

  4. Drag the chain along the surface of a toothbrush while you rotate the chain.

  Every few revolutions, rinse the brush off with degreaser.

  5. With a clean rag, grab the chain on the bottom, between the lower derailleur jockey wheel and the bottom of the chainring. Rotate the pedals in reverse to move the chain through the rag to remove the degreaser.

  6. After you’ve wiped down the chain, apply lubrication to the top of the lower rung of the chain, where it exits from the rear derailleur using a spray can or squeeze bottle.

  Be sure all the degreaser is removed before applying new lubrication.

  7. Rotate the pedals in reverse to move the chain as you lube it, completing ten revolutions of the chain to make sure you haven’t missed any links.

  You don’t need to douse the entire chain in lubricant.

  8. Wipe off any excess lubrication using a clean rag (refer to Figure 10-9).

  If you have a chain cleaning tool, follow these steps:

  1. With a clean rag, grab the chain on the bottom, between the lower derailleur jockey wheel and the bottom of the chainring.

  2. Rotate the pedals in reverse to move the chain through the rag.

  3. Fill the chain cleaning tool with degreaser to the mark.

  4. In front of the rear derailleur where the chain exits, enclose the tool around the chain and rotate the pedals in reverse.

  5. With a clean rag, grab the chain on the bottom, between the lower derailleur jockey wheel and the bottom of the chainring. Rotate the pedals in reverse to move the chain through the rag to remove the degreaser.

  6. Apply lubrication to the top of the lower rung of the chain, where it exits from the rear derailleur using a spray can or squeeze bottle.

  Be sure all the degreaser is removed before applying new lubrication.

  7. Rotate the pedals in reverse to move the chain as you lube it, completing ten revolutions of the chain to make sure you haven’t missed any links.

  You don’t need to douse the entire chain in lubricant.

  8. Wipe off any excess lubrication using a clean rag (refer to Figure 10-9).

  Replacing a Chain

  Despite your best efforts at keeping the chain clean, eventually all your pedaling is going to wear it out. The chain is under constant force and tension and, as it’s shifted back and forth across the different gears, it begins to stretch. You can still ride on a stretched chain, but it’ll cause your cogs and chainrings to wear out faster. Because replacing the chain is much cheaper than replacing the cogs and chainrings, we recommend replacing your chain at the first sign of wear. In this section, we talk about how to remove a chain and then how to measure it and reconnect it when you’re ready to reinstall it.

  Before you try to remove or install a chain, you need to know what type of chain you have (see “A Chain Is Not a Chain Is Not a Chain: Types of Chains,” earlier in this chapter). Each type of chain requires a different procedure for removing it and installing it.

  Unchain me! Removing the chain

  Before attempting to remove or cut the chain while it’s on a bike, shift it to the smallest cog in the rear and onto the frame and to the side of the small chainring in the front. If you don’t do this, the chain will be under tension and, as soon as it’s separated, it may be thrown back at you.

  SRAM PowerLink–type chains have a single master link that can be separated and reconnected with common hand tools (pliers and/or a screwdriver), making chain removal and installation a simple task. To remove a PowerLink-type chain:

  1. Find the master link.

  2. Pinch the outer plates together and, at the same time, slide one plate forward and the other plate backward.

  This will unlock the connecting plates and allow you to separate the chain.

  If you have the most common type of chain, the Shimano- or Campagnolo-type chain, you’ll need to use a special chain tool to push out one of the current pins and push another pin in its place when it’s time
to connect it. In order to cut the chain, follow these steps:

  1. Position the chain into the cradle of the chain tool that is farthest away from the handle (as shown in Figure 10-11).

  2. Turn the handle clockwise until the chain tool pin comes in contact with the chain rivet, and then stop.

  There may be one or more black rivets in the chain from where it was last connected. Select an original silver rivet.

  3. Examine the chain tool pin to make sure it’s lined up with the center of the chain rivet.

  Figure 10-11: Preparing to separate a chain

  4. Begin turning the handle to push out the pin.

  You may notice that it’s difficult to turn at first.

  5. Continue turning the handle until the pin falls out.

  If you have a chain with reusable rivets, follow the same procedure as for the Shimano and Campagnolo chains, but be very careful not to push the pin completely out of the link — you’ll use the same pin to reconnect the chain. The end of the pin has an expanded surface and you won’t be able to reinstall it into the link if you push it completely out.

  If you have any questions about your chain, consult your owner’s manual or visit your local bike shop.

  Measuring your new chain

  If you buy a new chain, you’ll find that it’s probably much too long for your bike — manufacturers sell chains longer than necessary so that they can fit a variety of different types of bikes. You need to make sure you’re using the proper length chain for your particular bike. If you use a chain that’s too short, you won’t be able to shift it into some gears. If you use a chain that’s too long, shifting will become sluggish or the chain will start to fall off.

  To measure a chain, follow these steps:

  1. Wind one end of the chain around the smallest cog and through the rear derailleur.