Bicycle Chain Features and Specific Recommendations
Most casual bike riders never give much thought to their bicycle chains. The truth is, they probably ignore their chain more than they should. Doing so is not only harmful to the chain, but also to the other parts of the drivetrain. A chain that is neglected or badly worn can cause damage to the chainrings and sprockets which are much more expensive to replace.
At the very least a cyclist should keep their chain well maintained. But if there is a need to replace the chain, there are some features that should be considered. For those who are casual riders and never plan to ride in the rain or get their bike dirty, there is no reason to pay for a more expensive chain. However, for road racers, having a chain that weighs less than the competition might make a difference in 1st or 3rd place. There are many good chains that fall in between these two extremes. Knowing the features of a chain can help the rider make an appropriate choice for their needs.
Bicycle Chain: Size
Chain size refers to two different measurements. The first is the length of the chain, which can be shortened as necessary. The second is the chain's width. This is the one that is most important since it cannot be altered like length.
Most bicycle chains are sold in lengths of more than 100 links. That is longer than most bicycles need. There are different calculation methods to know how long a chain needs to be, but there is one method that is simple and almost always fool-proof. Count how many links are on the current chain and cut the new chain to that many links. The new chain will be slightly shorter than the old chain using this method. The reason is the old chain has been lengthened by wear. Assuming the old chain was the right length to begin with, this is the easiest way to get the proper length for the new chain.
If unsure about the proper length of the chain, there are online calculators that can help. To start with, the new chain can be cut a link or two longer and then tested on the bike. If necessary, the chain can be cut again. Chains that are too long or too short will not be as efficient as they could be and can cause damage to other bike parts.
Modern chain widths are either 1/8" (3.175mm) or 3/32" (2.38mm). The wider 1/8" chains are for older, single speed bikes. Narrower 3/32" ones are for dÃ©railleur bikes of 6 speeds or more. This measurement applies to the internal width of the chain. There is also an external width that is often expressed in the number of gears.
As long as the chain that is being replaced is a modern chain, there is no need to worry about the chain pitch. That is the measurement between the rivets. All modern chains are 1/2" between rivets and 1" between full links.
Bicycle Chain: Material
Some chains are made of special material that are harder than other chains. This causes the chain to last longer, but at a cost of weight and expense. However, if weight and money are not an issue, then these chains can offer longer life with less maintenance. Some of these are hardened by heat treatment while others use special metals.
Chains can be coated with different materials that cause them to change gears more smoothly. One of the extra benefits is that road grime cleans off of them easily. These are usually coated with titanium nitride which has a slight gold color to them.
Some chains have a rust preventative coating on them. Though they won't protect a badly neglected chain completely from the natural oxidization of metal, they will make chain maintenance a little less critical. Usually it is better to spend a few minutes occasionally maintaining a chain, than to spend extra money for specialty coatings.
Bicycle Chain: Master Links
There are different types of chain master links. The most common is an outer plate with two rivets which go through the two inner links to connect the chain together. There is a side plate with a cotter pin that goes on the other side to lock the link in place. These are relatively cheap and are the type of master link that comes on most lower end bicycle chains.
Wipperman, SRAM and KMC each make a master link that is both high quality and easily removed without tools. Any of these master links can be installed on an appropriately sized chain; even if it is not from that manufacturer. At less than $4 per link, they are cheap enough to keep a spare in an emergency tool kit.
Bicycle Chain: Specific Recommendations
Bicycle chains can range in price from less than $10 to well over $100. While most riders won't need a $100 chain, buying the cheapest may not be the wisest choice either. A less expensive chain is usually softer and will wear out quicker than an harder chain. Unless you need a specialty chain, a good chain can be had for under $30.
The SRAM PC 971 is one of SRAM's better chains (though they all perform very well). When looking at SRAM chains, the higher the product number (in this case 971) the greater the load capacity it is rated for. This chain includes their PowerLink master link.
The Shimano CN-HG93 Ultegra/XT chain does not come with a master link, but is a good chain with high customer satisfaction. They are specifically designed for Shimano drivetrains, but can be used on characteristically similar gear sets.
When buying a chain and comparing features, one should always make sure it is appropriate for a bike with the same number of gears as theirs. Many chains are available with the same characteristics in different widths and gearings. A local bike shop can quickly recommend an appropriate chain if help is needed.
Good chain maintenance is cheaper than replacing the chain all the time. However, there are times it is necessary to get a new chain. Chains do wear out and therefore are necessary to replace before they damage other parts of the bike.