Chains

• Components: KMC MZ9000 MTB / ROAD 9SP CHAIN

• Components: SHIMANO ULTEGRA CN-6600 10SP CHAIN

• Components: SHIMANO CHAIN PINS SET OF 5

• Components: SHIMANO CN-7701 9SP CHAIN

• Components: SHIMANO CN-7800 10SP CHAIN

• Components: SHIMANO HG-73 9SP CHAIN

• Components: SHIMANO HG-93 9SP CHAIN

• Components: SHIMANO IG-90 8SP CHAIN

• Components: SRAM PC 971 9SP CHAIN

• Components: SRAM PC 971 9SP CHAIN

• Components: SRAM PC-68 8SP CHAIN

• Components: SRAM PC-951 9SP CHAIN

• Components: SRAM PC-951 9SP CHAIN

• Components: SRAM PC-991 9SP CHAIN

• Components: SRAM PC-991 9SP CHAIN

• Components: SRAM PC-991 HOLLOW PIN 9SP CHAIN

• Components: SRAM PC-991 HOLLOW PIN 9SP CHAIN

• Components: SRAM POWERLINK

• Components: WIPPERMAN CONNEX STAINLESS LINK

It is easy to take chains for granted. Almost, every bike has one, and the way the chain works appears so simple that it's hardly interesting. Besides, who wants to have anything to do with a piece of hardware that's often the dirtiest thing on a bike, a part that calls attention to itself mostly by the grimy tattoos it leaves on a clean pair of pants or a leg?

You should, if you're a regular rider. No one likes the results of contact with a dirty chain. But the grease that it transfers to your hand or leg is not its only drawback; a dirty chain can also rob you of some of your pedaling power. Furthermore, on de­railleur-equipped bikes, a dirty chain can impair shifting performance and accelerate wear on de­railleurs, cassette cogs, and chainrings.

For these reasons, pay attention to the chain and frequently clean and tube it. But before you begin working on your chain, you should know what kind of chain you're dealing with.

Chain Identification

There are two common sizes of bicycle chain: 1/8-inch width, which is used on most BMX bikes and all 1-speed and 3-speed bikes; and 3/32-inch width (also known as derailleur chain), which is used on all 5-, 6-, 7-, 8-, 9-, 10-, 12-, 15-, 16-, 18-, 21-, 24-, and 27-speed derailleur bikes. The width referred to is the thickness of a compatible gear tooth. The span between the two inner plates of a chain link must, by necessity, be slightly wider than the teeth that will fit into the space.

If you can't identify the chain size of your bike from its type of drivetrain, measure the thickness of one of your bike's gear teeth. It should be either 3/32-inch or 1/8-inch. If your bike has a 1/8-inch chain, you're all set. If your bike is equipped with 3/32, or derailleur chain, you must determine what type.

Chains come in different widths, to correspond with different drivetrains and their different num­bers of cassette cogs. If you're replacing a derailleur chain, it's important to correctly identify its type. The easiest way to do so is to count the number of cogs on the rear cassette. The more cogs, the nar­rower the chain. Shops will be able to select the appropriate chain if you can tell them how many cogs are on the cassette and what type of de­railleurs and shifters you have (or just take your bike in and show them). Pay attention because a mistake here will, at the very least, diminish your bike's ability to shift smoothly. At the worst, it may no longer shift at all.

Standard width: Standard-width chains are usually found on older bikes with five and six cogs. They won't work properly on modern seven-, eight-, and nine-speed drivetrains. With practice, you may be able to distinguish standard-, or normal-, width chains by their slightly greater width. If not, look first at the surface of the inner plates. Most standard derailleur chains have straight-edged plates or sometimes plates bulged to the outside. In addition, standard-width chain pins protrude about 3/32- inch beyond the sides of the outer plates.

Narrow width: Narrow-width chains are ap­propriate for seven- and eight-speed drivetrains. Complicating matters, the new nine-speed drive­trains take an ultra-narrow chain. The designs are similar, though. The inner links of most narrow-width chains have slight bulges on their edges. This is to help counteract the slightly smaller opening in the narrow chain that the gear teeth must fit into. That narrower opening makes shifting less accurate. So, even though a narrow-width chain will work with a standard ­width freewheel, don't try it. That combination just doesn't shift as well as a properly matched chain and freewheel.

Another visual tip-off to narrow chains is their flush chain pins. The ends of these pins barely pro­trude beyond the surface of the chain's outer links. The extra side clearance that the flush pins provide allows the narrow chain to settle down onto the co teeth of a narrow freewheel's cogs without interfer­ence from each cog's neighbors. If you ever try a standard-width chain on a narrow cassette, you'll see firsthand how necessary that clearance is: The standard-width chain won't be able to engage any of the cogs.