Workin' On The Chain Gang

Salt and grit does serious nastiness to bike chains. They wear much faster in the winter. The moment you notice your chain begins to jump while you pedal, its time to replace it. It's actually past time to change it. But timely replacement of a chain will save you a lot more money than if you defer the work until the chain's looseness is intolerable. 

With use, the links in your chain gradually stretch. If you change it right away, all you'll need to do is replace the chain. But if you ride long enough with a stretched chain, the elongated links will wear down the teeth of your rear cassette. Then you'll need to spend an extra $45 on a new cassette. too. If you ignore that and manage to keep riding with a chain that's skipping teeth badly, you may need to replace the front chain-rings, too. That's a few hundred $.

There are a few approaches to chain maintenance: 

     1. Change it every 1000 - 1500 miles. This is best practice. For me, it results in changing chains a couple times a year. This is least expensive in the long run because you don't need to replace the rear cassette as often.

     2. Change it when you can measure that it's stretched. There's a nifty little measuring tool that you insert in the chain to measure the link-to-link distance. If it won't slide into the chain, then your chain is still okay. If the tool fits, then the chain needs replacement. This requires periodic proactive checks. Monthly?

     3. Change it when you notice it jumping teeth while you ride. This is most common, but most expensive because it can result in damage to other components.

You'll need a specialized chain tool and a pair of pliers for this job. Chain tools are miniature hand vices. They cost about $15 which is cheaper than paying someone to do the job.

To buy a replacement chain you need to know the manufacturer and component line of your gears and the number of teeth on the rear cassette. This one is a 9-tooth Shimano Diore/Ultegra. Although other suppliers sell replacement chains that are cheaper, I find that they're noisier and don't shift as smoothly. Don't combine SRAM, Campy, and Shimano components in the same drive train. It's not pretty.

The job will be easiest if you shift the front derailleur to the smallest (easiest) ring and the rear derailleur to the smallest (hardest) cog.














Use the chain tool to drive out one of the link pins. Then pull the old chain out. This is a good time to show the remaining drive-train components a little love and clean them up with a used toothbrush.















Check the new chain against the old one and confirm the new chain has the same number of links as the old one. You may need to remove a few links using your chain tool.

Slide the new chain back through the derailleur, around the rear cassette and over the front chain-rings so it's hanging loose on both ends. Look at a different bicycle or YouTube video if you're unsure about what route to thread the chain.

There are a few different types of connecting mechanisms for new chains. Shimano supplies an extended "break-off" pin with each chain to make insertion easier.

Grabbing both ends of the new chain with one hand, use the other hand to manually insert the new pin through the two ends of the new chain to hold them together.

Then use the chain tool to drive the new pin into place. As you drive it in, you'll feel hard resistance, then light resistance, then hard resistance again. Watch carefully so you don't drive it too far and out the other side.






 Use pliers to break off the end of the new link pin. Then verify that the new links flex smoothly. If you've driven the new pin in too far or not far enough, the links will bind. If so, you may need to monkey around with the chain tool to get it set properly.

Most new chains come pre-lubricated. Adding more oil will only attract more dirt. If the new chain does come with no lubrication, use only a few drops of oil on it. Note that WD-40 is primarily a cleaner, not a lubricant. Use proper chain oil.


Clean up the tools, recycle the waste, wash up, and take your bike out for a short spin. Shift up and down through all the gears to confirm everything's working smoothly.

As soon as you get inside, order a new chain and keep it on the shelf so you're ready for next time!