You may not give it much thought, but your chain is the driving force on your bike. It transfers the power from your pedaling into the gears that propel your bike forward. It's also one of the most neglected parts on a bike. Road grime, mud and salt spray wear the chain down and, like you, age causes it to slacken. Some chains have a master link or rivet that makes removal a snap.
Finding the Master
To find the master link on your chain, mount your bike in a bike work stand. If you don't have a work stand, flip the bike over so it rests on its handlebars and saddle. Stand on the drivetrain side of your bike so you're able to look straight down on the chain. Slowly turn the pedals to rotate the chain as you watch each link go by. You'll notice one link is wider than the others. That fat one is your master link.
About Master Rivets
Not all bikes have master rivets. If your bike has a derailleur, it's unlikely that your chain will have a master link. Bikes that typically do have chains with master links are BMX bikes and one- or three-speed town bikes with internal gears. You can also identify if your chain should have a master link by measuring the width of the gap between the link plates. If the width is 1/8 inch, your chain should have a master rivet.
Unlocking the Rivet
The master rivet allows you to open your chain without the use of a chain tool. The rivet will either have a spring clip that looks like a long horseshoe on the side of the link or special easy-release pins. With the spring clip link, take a pair of needle-nose pliers to pull off the piece that looks like a horseshoe. You can then pull off the sideplate of the link and slip the chain apart. With a pin-type master link, bend the chain at the master rivet as if trying to form the link into a U. This loosens the sideplate. You can then pull off the plate and take the chain apart.
Missing Master Link
If you can't find the master rivet on your bike or have a chain without this master link, you can use a chain tool to open your chain. Before using the tool, slip your chain off the front gears to keep the chain from snapping you when the tension is released. Position your chain tool over any link so the rod of the chain tool lines up with a pin on the link. You then turn the lever on the chain tool to push the rod forward until the pin pops out. Your chain is now open and ready for cleaning or replacing.
Based in Portland, Ore., Tammie Painter has been writing garden, fitness, science and travel articles since 2008. Her articles have appeared in magazines such as "Herb Companion" and "Northwest Travel" and she is the author of six books. Painter earned her Bachelor of Science in biology from Portland State University.