The reason to install a master link to your bike chain is to have an easy way of removing the chain when you need to wash it thoroughly or replace it together.
To install a master link on a bike chain you need to remove a pin from the chain using a chain breaker tool and then install the new master link in place of the old removed outer plates. Apply force when connected on both sides to properly lock it in place.
What is a master link
A master link is an easily removable bike chain plate that helps you remove your chain. It is often called a quick link, a missing link, or a spare link.
Advantages of a master link
On the occasion you need to remove a bike chain, using a chain breaker will remove the pin which if putting it back will not be the same. When a bike chain breaks, it’s the pins that break. They take all the heavy lifting, so removing one will damage it even further. Using a master link can allow you to remove a bike chain whenever you like without having to worry about having a damaged chain.
Are there different types of master links
There is no universal master link as there is no universal bike chain. Bike chains differ in width depending on what cassette you have on the back wheel. So a 9-speed bike chain would require a 9-speed master link.
All chain manufacturers offer master links as well and even though you can install a different branded master link, it is recommended to buy the same brand.
Another thing to take into consideration is that master links are of 2 types: reusable and non-reusable. Be sure to buy the ones you need and be careful that not all product descriptions display this information.
How to find a master link on a bike chain
The master link is the only one that is different from the bunch. Having an extra larger hole for the opposite side to connect.
How to install a master link on a bike chain
There is a tool that you cannot install a master link and that is a bike chain pin removal tool. You can get away with not having bike chain pliers for the installing process, but it will help you at the master link removal stage.
As an optional first step, you can use a bike chain hook to hold the chain connected and not wobble around when taken apart. Either way, a tip would be to work on the bottom part of the chain as it is easier since you will have the cassettes holding the bike chain and you can let go if needed.
The next step would be to use the chain breaker to remove a pin. The plates on both sides will now be loose and you are now ready for the main step of the whole process.
Installing the master link is as simple as connecting an end on one side of the chain and the other on the other opposite side of the chain. Connect them through the larger whole which is always the one in towards the center and with your hands try to lock them in as best as you can.
On smaller speed bike chains you will succeed with just your hands, but on the higher speed bike chains, you will need bike chain pliers or a simple physics trick. Place your bike on the ground if it wasn’t already, move the master link on the upper side, and press on the pedal while braking. You should hear a distinct pop sound.
How to remove a master link from a bike chain
Here is where bike chain pliers can help you greatly. Use the pliers on the outer hubs of the master link and you are all set. You may want to use the bike chain hook if you already have it since it will help you the same way as when installing.
A DYI hack here would be to use a rope on the outer hubs, but that is a solution on smaller bike chain cassettes as they are not so tight.
Can you install multiple master links on a chain
Yes, you can have multiple master links installed on a bike chain. You can even have the whole chain replaced with master links. Here’s a YouTube video of a bike chain made out of entirely master links.
Do all bicycle chains have a master link
Not all of them have it installed out of the factory, but all bike chains can have a master link installed. Bike chains are all built the same way.
How to replace a bike chain without a master link
Replacing a bike chain without a master link still requires a bike chain breaker tool to remove the old bike chain and to use it again on the new one to set the appropriate length and install it.
Conclusion
Installing a master link on a bike chain is not a hard process, but it requires some special tools to finish the job successfully. Whether it is a good idea to have a master link depends on you entirely and how often you want to thoroughly clean your chain or have an easier way of removing it if needed.