important: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.

How to Use a Chain Tool to Break a Chain

How a chain tool works, and how to use it to disconnect and reconnect your bike chain.

This week we’ll learn how to break a chain using a chain tool. I’ll cover the quick release method next week.

Quick Release Links

The first thing to do is check to make sure your chain does not already have a quick release link. Do this by turning your pedals backwards and carefully watching every chain link as it goes by. A quick release link will stand out as they look different from all of the others. If you find one, you can refer to next week’s tutorial for removal and installation instructions.

The Chain Tool

If you can’t find a quick release link, then your chain probably doesn’t have one. This has traditionally been the most common type of chain, and it requires a chain tool for both removal and installation.

Turn the handle of your chain tool counter-clockwise until the pin has backed off enough so you can place one of your chain links on the outermost slot, furthest from the handle. There are two places on chain tools where you can place a chain. The outer slot is for disconnecting and re-connecting the chain, while the inner slot is for loosening chain links.

Disconnect the Chain

Now tighten the handle clockwise until the chain tool’s pin connects with the end of your chain pin. Continue tightening the handle and you’ll see the chain pin get pushed into the link and start coming out the other side. The tricky part here is to push the chain pin far enough so that it is gets about halfway through the first of the two outer chain plates. If the chain pin gets pushed all the way out of the chain there is really no way to get it back in, and you’ll be forced to shorten or replace your chain.

One way to prevent this is to pay careful attention to how easy the handle turns as you push the pin through. When you get close to the end, you’ll feel resistance and the handle will become a slight bit harder to turn. As soon as you feel this, stop tightening the handle, and then give it another half a turn. This is usually the perfect spot to disconnect the chain. When you take the chain tool off, you’ll notice the chain is still barely held together, but can be easily disconnected by twisting and pulling the chain.

Reconnect the Chain

Notice how a tiny bit of the pin is still poking out of the inner side of the outermost plate. This is perfect, as it will help us re-install the chain. Twist and push the links back together until the chain pin clicks back into the inner link, once again holding the chain together.

Now back off the chain tool’s handle and place the chain back onto the same outer slot of the chain tool. This time position it so the protruding chain pin faces inward toward the chain tool’s pin. Now tighten the handle until the tool pin starts pushing the chain pin back through the link. Continue tightening until a tiny bit of the link pokes through the other side. Now take a look at both sides of the link… the chain pin should stick out roughly the same amount on either side.

Loosen the Chain Link

The process of re-connecting the chain caused the chain links to compress together, making a stiff link. To fix this, we use the inner slot on the chain tool. Back off the chain tool all of the way so that you can place the freshly connected link into the inner slot. Now tighten the chain tool’s pin until it connects with the chain pin and tighten it just barely, about a quarter of a turn. This usually loosens the chain link plates enough. Remove the chain from the tool and check to make sure the link is loose. If it’s still tight, try loosening it with the chain tool another quarter of a turn.

By Alex Ramon

A bicycle geek since early childhood, spent his twenties as a mechanic in bike shops. His passions include flatland BMX, unicycles, cycle touring, mountain biking and road riding.

Recommended Tools

Discuss this topic in the Bicycle Repairs and Mechanics Forum

Columbia 3 wheel differential

Front derailer not moving

What are the best cost effective ways to prevent chain rust?

How to deal with rusty chain

Rear v-brake repair

Custom Bike part manufacturing

Removing and refitting rear wheel on belt drive bike?

Best way to thoroughly clean a chain?

Latest post 3 months ago

Hi everyone! I hope you're enjoying a great start to 2023. I'm curious to hear your go-to method for getting a chain truly clean. I don't mean, just looks shiny or is good enough for a quick clean after a ride. I want to know what you do when you want to get every last morsel of ground-up, link-destroying, roller-eating, tooth-gnashing crud out of your chain. The Best Chain-Cleaning Recipe Ever?...

What jockey wheel Red 10 Speed

Latest post 3 months ago

Can anyone advise what type of replacement jockey wheel I need for a 10 speed Red rear mech (it's got 11 teeth)? Bonus points if it's a link to a cheap (ish) one! Thanks...

Grip Shifters

Latest post 3 months ago

Currently renovating a child's bike. It has 24 inch wheels and is a suitable size for a 7-10 year old. Anyway it has grip shifters. it is a six speed with three chain rings on the front derailleur. On the rear derailleur the shifter does not appear to move the gear cable at all when shifting from 6 to 5 and 5 to 4. I am actually holding the cable with my finger and thumb against the cable cas...