Before bikes had chains, pedals were attached directly to bicycle wheels. This limited a bikes speed to the size of the wheel, leading to designs making the front wheel as big as possible. The bicycle chain allows force to be efficiently transferred from the pedals to the bike, allowing for faster speeds to be achieved in more compact designs. As an integral part of the bike, the chain is put under almost constant strain whenever in use, meaning that over time it gets worn down and ‘stretched’. Considered a consumable in the biking world, the chain is one of the easier parts of a bike to replace, however, one of the most common problems. This guide will provide a detailed outlook in how to replace an old and inadequate chain on a bicycle with a new one in the most efficient technique.
How to Tell if You Need a Replacement
It may not be immediately obvious that a bike chain needs to be replaced. This is because a chain wears down by ‘stretching’, meaning a worn chain will be slightly longer than a new one. This is caused by the pins holding each link of the chain together becoming worn down. As each chain link goes through the gears of a bike, it rotates around the pin holding it in place. In a particularly worn chain, this can result in visible grooves being cut into the pin. A chain will become worn out more rapidly depending on how much dirt and grit gets accumulated on the chain.
To tell how worn a chain is, it has to be measured. This can be done using a specifically designed chain checking tool,, but is also possible with a ruler. The stretching effect on each individual chain link is too small to accurately measure, so instead the cumulative effect on a length of chain needs to be measured instead. If a 12 inch ruler is placed with one end directly above a chain pin, the 12 mark on the ruler should fall directly over another pin on an unworn chain. The more worn a chain is, the further away the pin will be from the 12 inch mark.
Distance of Pin
State of Chain
1/16th of an inch or less
The chain is still in good condition, and does not need to be replaced.
1/16th to 1/8th of an inch
The chain is showing signs of wear, and should be replaced at the next convenience.
Over 1/8th of an inch
The chain has been severely worn, and should be replaced as soon as possible. Other components, like the gears the chain goes around, may need to be replaced as well.
It is important to not allow a chain to become too worn. If a bike with a very worn out chain is used, it can not only cause the chain to slip and skip, making the bike difficult to ride, but can also cause more damage to other components of the bicycle, which are often costly and difficult to replace.
Finding a New Bike Chain
On modern bikes, chains are largely standardised, making it relatively simple to find a chain that will fit a particular bike. The key variation in modern bike chains is the internal width. This is important because a too wide or thin chain may not fit correctly on a gear. If a bike is a single speed bike, then any 1/8 inch wide chain will fit properly. If the bike has a ‘derailleur’, a collection of gears fitted to the wheel, then the bike will need a 3/32 inch chain,, and the ‘speed’ of the chain will also have to be taken into consideration.
It is possible to tell what speed a bike is by counting the number of individual gears on the derailleur. Six, for example, means the bike is a six speed bike. The bike chain will have which speed it is suitable for listed in the product description. As a general rule, chains which fit five, six, seven, or eight speed bikes can be used interchangeably. Nine, ten and eleven speed bikes, however, will need to be fitted with specific nine, ten or eleven speed chains respectively. Chain length is not important, as all chains are sold at similar lengths and will need to be shortened to fit the bike.
Removing the Old Chain
Unless a chain has an easy release link, which can be squeezed together with fingers or pliers to break apart the chain, a chain tool will be necessary. This device works like vice. To remove the old chain, you need to go through the following steps:
- A chain link must be placed into the tool so that the pin extractor is lined up with the pin.
- By turning the screw, the extractor will slowly push the pin out of the chain.
- It is important to avoid pushing the pin all the way out, as they can be extremely difficult to push back in.
- Once the pin has been pushed out enough it will be possible to pull the chain apart.
- After this, it is simply a matter of pulling the chain out of the bike.
- As the chain is pulled through the gears, it is important to make a note of how the chain runs through them.
- This is how the new chain will have to be fitted.
Fitting the New Chain
Firstly, the new chain will have to be shortened so that it is the right length for the bike. This is because all chains are sold at roughly the same length, so that they can be shortened to fit a wide range of bikes. The number of links on the new chain will need to be the same as the number of links on the old chain. Once the basics have been materialised, the following actions should be implemented:
- Using the chain tool, push the pin until it is possible to pull apart the chain, and remove the excess length.
- Once the chain is at the correct length, thread the chain through the bike in the same way that the old chain was.
- Once the chain is on the bike, line up the chain tool again and use it to push the pin into place, reconnecting the ends of the chain.
- Once this is done, adding a drop of oil to each chain pin will improve the new chains performance.
- Once this has been completed, you are then free to take your bike back out on the road, and ride freely again.
However, it is advisable to trial your new chain over short distances to begin with until you are fully comfortable that you have installed it correctly.
Finding a Bike Chain on eBay
eBay offers a wide variety of chains and other bicycle components, which can be found in the Bike Parts section under Cycling,, which can be found in the Sporting Goods portal. Buying through eBay means it is possible to choose from an enormous selection, and to take the time to make sure that a chain is the right one for a bike. The important information, like the chains width and speed compatibility, will be prominently displayed on the item’s entry, making it easy to see the specifications at a glance. This should definitely help you with short-listing some of the product listings on the eBay website.
More detailed information about a specific item will be available on the page of the item. Information about the seller will also be available here, and it’s often a good idea to have a look at the seller profile before making a purchase. This will provide information like the seller’s feedback rating and the quality of the items they sell, meaning a purchase can be made with confidence.
To find a chain with a specific set of specifications, or one made by a specific manufacturer, it is possible to use the search function. Searching for a specific chain here will bring up exactly what is needed. For advice on using the eBay search function, visit the Search Tips page. If there is any uncertainty about a chain, it is possible to ask the seller a question regarding the item. Once you have carried out all the research and gained all the information needed, you can purchase in the safe knowledge that eBay have the most creditable sellers at your fingertips.
Ensuring a bicycle’s chain has not been worn out is important both for the safety of the rider and the performance of the bike, as has been provided through this guide. Chains are considered ‘consumables’ in the biking world, meaning that they come with the expectation of being changed fairly regularly. The chain is one of the easiest and most affordable components of a bike to replace, and replacing it before it becomes too worn can help protect other, more expensive bike components. Finding the right chain on eBay is simple, with the necessary information easily accessible. Before making a purchase, be sure to have the correct specifications of the bike. With a new chain, a bike is safer and more enjoyable to ride.