Look for places where the chain has become jammed against the frame—these jams must be addressed before the bike can be ridden again.
Open the quick release by first pulling the small lever at the center of the rear wheel. Then, loosen the wheel nut on the other side to loosen the “hold” the rear wheel has on the frame. Once loosened, the chain should come out easily. Don’t forget to re-tighten the quick release before riding away. You should be able to close it completely—it should be tight, but not too tight to push all the way down. If it feels too tight, loosen the wheel nut and try again. Likewise, if it’s too loose, then tighten the wheel nut.
From here, you can usually simply ride away! Your bike may shift somewhat erratically until the chain shifts into the gear it was in when the slippage occurred.
Turning the pedals is easier if you elevate the bike’s rear wheel. To do so, you can put the bike on a stand or prop up the rear of the frame with any materials on hand. Alternatively, you may get a helper to hold the rear wheel off the ground as you put the chain back on or turn the entire bike upside down.
Note: on fixed-gear bikes, chain slippage can be particularly dangerous and problematic and is often the symptom of a chain that’s too loose. Consider adjusting the tension in your chain by sliding the wheel rearwards before riding again.
You can purchase these items in a sporting goods store or cycling shop.
Chains with special replacement pins. These chains require a special type of pin from the manufacturer (usually provided when you buy the chain) to repair a break. If you don’t carry these special pins with you when you go riding, you may be out of luck in terms of repair options until you can make it to a bike shop. Chains with master links. These chains have a special link with 2 pins that is used to join the 2 ends of the chain. If this link is broken, you may need to wait until you can replace it to be able to repair the chain. Chains with “normal” pins. Older, more traditional chains have uniform pins, any of which can be used to repair a breakage (provided you have a chain tool with you).
To use a standard chain tool, simply line up one chain link in the tool’s internal groove, securing it on the tool’s “teeth”, then turn the chain tool’s handle to drive the tool’s point down and push the pin out of the chain. If you want to reuse your chain, make sure you only push the pin far enough out of the way that the 2 links can be separated. Don’t push the pin all the way out, as they’re quite hard to replace. Once you’ve introduced a break in the chain, simply turn the pedals to pass the broken chain through the bike’s gears. Ideally, you want to buy a replacement chain that’s the exact same length as the chain you had before (though bikes with a rear derailleur allow a small margin of error), so now is a good time to count the links in your chain. You should also make note of the type of drivetrain you have, as this determines which chains are suitable. For example, 9-speed drivetrains require 9-speed chains, and so on.
Also, make note of your derailleur arrangement. If your rear derailleur has a cable connected to your shifting mechanism, shift into the highest gear (or onto the smallest cog, in the rear). If the front derailleur has a cable connected, shift into the lowest gear.
There may be a small metal “tab” between the 2 small pulleys in your derailleur. The chain must pass this tab without rubbing on it. Some bikes, like fixed-gear bikes (“fixies”) and bikes with a hub gear shifting mechanism, don’t have a derailleur. In these cases, simply thread the chain onto the rear sprocket, turning the wheel as needed.
Again, “fixie” bikes usually won’t have a front derailleur, so simply thread the chain around the front sprocket.
One useful tip is to use a small, thin piece of metal called a “C-hook” to hold the 2 ends of the chain near each other. This makes it much easier to work, as you won’t have to worry about holding the chain in place yourself and potentially losing either end. In a pinch, a bent paperclip can substitute for a real C-hook. In some cases, if you connect a chain that doesn’t use a master link, the pin that you use to connect the ends of the chain can make the link stiff. This can cause a hitch or a rough spot in your pedal stroke. To fix this problem, work the links on either side of the stiff link in a direction perpendicular to the way the chain rotates (i. e. , on the bias).
