Repairing a broken chain

A broken chain is a pretty infrequent event, though as newer chains are manufactured to be narrower this occurrence is becoming increasingly more common. When a chain breaks, the outer plates on one of the links are twisted and/or ripped off, causing damage to the link and possibly to your bike. You can repair the chain in an emergency, but as soon as you get home, you should replace it.

To repair a broken chain:

1. Remove the chain from the bike and, using a chain tool from your emergency tool kit, remove the affected link or links.

Follow the instructions in Chapter 10 for using the chain tool.

2. If you have extra links, use the chain tool to connect the extra links to the chain, replacing the damaged links.

If you don’t have extra links, you can shorten the chain by removing the faulty links and reconnecting the chain. However, you most likely won’t be able to shift into the gears when the chain is in the larger cogs in the rear and the largest chainring in the front.

3. Reconnect the chain using the chain tool and following the steps in Chapter 10.

Examine all the rivets and links to be sure that there are no other weak­nesses in the chain.

Extracting a jammed chain

A jammed chain (like the one shown in Figure 4-3) can be one of the most annoying malfunctions when you’re riding. A jammed chain often happens when the front derailleur shifts the chain too far inward and over the small­est chainring. It can also be caused by a worn chainring not grabbing the chain properly or mud clogging the chain and chainring.

Figure 4-3: A jammed chain.

Dennis has had this happen to him while shifting into his smallest or “granny” gear during a steep climb. Trying to stop pedaling when you’re on a sharp incline on a bike loaded down with pannier bags is awful — it takes all your energy not to fall over and become fresh roadkill.

The best thing to do when you hear a loud, grinding sound when you shift is to stop pedaling immediately. If you continue to apply force to the pedals, you could further jam the chain and make it even more difficult to remove.

To extract a jammed chain:

1. Try pulling on the chain to separate it from the chainstay and chainring.

Be careful not to twist it — you don’t want to damage the chain in any way.

If pulling on the chain is not enough to free it, try rotating the cranks backward while you pull the chain.

This is often enough to spring the chain loose. If not, move to Step 3.

Insert a screwdriver between the chainring and chainstay and, using it as a lever, gently pry open the space.

This should allow you to slide the chain out (if not, move on to Step 4). Check the chainrings for any damage caused using this method and straighten as necessary.

Separate the chain with a chain tool.

Note: This step should only be used as a last resort, when all the preced­ing steps fail.