How to Replace a Chain on a Bike - Sizing & Installation

In this video, we'll walk through how to replace a bicycle chain. Replacing a chain is good preventative maintenance, kind of like changing the oil in a car. It prolongs the service life of other more expensive parts of your bike, so replacing your chain is a good way to save some money. We'll take you through it step by step and include all the important details needed to get the job done right. If you have a single speed bike, check out our video on chain replacement for single speeds. And if you're running a Campagnolo drivetrain, be sure you've already watched our video on Campagnolo chain sizing. Hi, I'm Bannon with Park Tool. We've already checked the wear of our chain and determined it needs to be replaced. Learn more about that process in this other video. As for choosing the right chain for your bike, it's generally accepted to A. Count the cogs on your rear wheel. Make sure your new chain matches that number. And B. Match the manufacturer of the chain to the manufacturer of your rear derailleur. The more expensive chains are often lighter and more durable than their cheaper counterparts. Other tools and supplies include a master link pliers for chains with master links. For connecting rivet chains, you'll need a drop of lube for the rivet. And a chain tool to break the chain and drive the pin. Finally, you'll need a can-do attitude. Before we remove the chain, we need to confirm it's the correct length. We'll shift to the largest front and rear sprocket. The chain should be able to make this shift. And it should have two slight bends, one in each pulley. Next, shift to the smallest cogs. There should be no slack in the chain. And the derailleur should not pull so far back that the chain contacts itself. So on this example bike, the chain is sized correctly and can be used to size our new chain. Now, we remove the chain. An option is to first remove the wheel. This takes tension off the chain and makes things a little easier. Inspect the chain for a master link. Master links have a unique side plate and are sometimes a different color. If a master link is present, position it in the lower section of the chain. And use master link players, such as the Park Tool MLP 1.2 to disengage the link. Alternatively, you could use needle nose players, but it's difficult at best. And doing it by hand is extremely difficult as well. If you have a chain tool and your chain is worn out, you could ignore the master link and simply break the chain the same way you would on a connecting rivet chain. We'll walk through that process next. Connecting rivets will appear visually different from the other rivets. When selecting a rivet to break, be sure it is several links away from any connecting rivets already installed in the chain. Bring the driving pin of the chain tool into contact with the rivet. And ensure the chain tool pin is driving in a straight line into the rivet. Turn the handle with force and drive out the rivet. Then remove your chain. Since our original chain was an acceptable length, we'll use it to size our new chain. If there is no original chain available, see our separate video on chain sizing. Always line up ends with outer plates. This example is incorrect because we have an end with outer plates being compared to an end with inner plates. Insert the master link to get a true side-by-side length comparison. In this other example, neither end of the chains have outer plates. So in this case, we would line up inner plates at either end. Next, we line up the chains. Take care to match them rivet by rivet, noting that old chains will lengthen as they wear. This is the rivet that we will cut on the new chain. And the chain is sized. Before we begin routing the chain, inspect the chain side plates. Some chains are directional, and any logo or printed letters should face outward toward the mechanic on the drive side. The process of routing the chain is the same for both master link and connecting rivet chains. Just remember to lead with the outer cage plates if your chain uses a connecting rivet. Master link chains have inner cage plates on both ends, so you can lead with either end. Feed the chain through the rear derailleur as shown. Be aware of any tabs in the cage and route the chain on the correct side of the tab. Bring the chain inside the frame, through the front derailleur, and bring both ends of the chain together. Now we'll walk through connecting the chain, starting with the master link chain. If your master link chain has an arrow, line it up with the direction of travel. Engage the master link pliers and pull outward to seat the pins. An alternate engagement method is to rotate your crank until the master link is on the upper row of the chain, apply the rear brake, and then apply force to the pedals. Inspect to make sure the master link is fully engaged. Now we'll connect a chain that uses a special connecting rivet, such as Shimano and Campagnolo chains. The connecting rivet has special flaring that is guided in a long, tapered pilot which is broken off after the rivet is fully installed. Each rivet is specific to the make and model of chain, so be sure to use the proper connecting rivet for your particular model of chain. Lubricate the connecting rivet. Install the rivet into the chain from the inside of the bike toward the mechanic. Install the chain tool. Drive the connecting rivet into the chain. There will be two points of resistance. The first as the pin begins to go into the first cage plate. Then you'll feel the resistance slack off, and it'll ramp up again as it starts to go through the outer cage plate. The key is to match the depth of the neighboring rivets. That's when you'll want to stop and double check that your pin isn't protruding too much or needs to be driven in further. And this looks good, so now we can break off the pilot tip using the chain tool or pliers. For Campagnolo 11 speed chains, after the pilot is broken off, we need to press the pin. Using a chain tool with peening anvil such as the CT 6.3 or the CT 4.3, set the peening anvil and chain in place. This is the side the tip was broken off. Run the tool up to contact so the rivet sits between the anvil and pin. Then press an additional quarter turn. And we're done. So now that we've snapped off the pilot tip, we can see a good case for driving the pin from the inside out. The connecting pin's burr is on the outside, preventing it from making contact with any inboard cog and creating noise. Reinstall the wheel and back pedal to inspect for any tight links. Repair is necessary by flexing the chain laterally at the tight link. Once you've installed your new chain, if you encounter issues such as skipping, it might be a symptom of worn cassette or freewheel cogs, so you might need to replace those. As for lubrication, if it's a brand new chain, that's generally not necessary. But if you've reinstalled your old chain, it might be a good idea to lubricate it before riding. Well, that'll do it for replacing a chain on a multi-speed bike. This video is part of our series on chains, and to get a quick snapshot of other chain related videos, watch this video. Thanks for watching.