How To Shorten A Bike Chain: A Comprehensive DIY Guide

You’re biking along this scenic stretch of highway and all of a sudden your bike chain comes undone. What do you do when there’s no mechanic on the road other than yourself? This is when shortening the bike chain comes into play.

There are a couple of ways to shorten it — the manual way or the chain cutting tool way. Even if you are not the most technically adept person, this quick fix guide should sort you out.

Shortening the bike chain is less complicated than many other fixes. It is quite hectic to go to a mechanic when it comes to auto-tuning or any mechanical work.

What if you learn the small fixes by yourself with a smart approach? Here we’ll do just that, essentially walk you through “how to shorten a bike chain.”

Don’t forget to read till the end, as we have some amazing tips in this article for your bike chain prevention.

Methods For Shortening A Bike Chain

For the ease of understanding, we will say, there are two methods to shorten a bike chain:

  1. With the help of a chain cutting tool
  2. With the help of some manual tools (without chain cutting tool)

How To Shorten A Bike Chain Using A Chain Cutting Tools

how to shorten bike chain

Assuming that you have to shorten your bike chain at home, you’ll need the following:

  1. Chain Tool
  2. Master link (also known as a rapid link under several proprietary names)
  3. Pliers for master links
  4. Installation tool/chain hook

The master link pliers are useful as separating quick links by hand is not always straightforward. On a bicycle, you may accomplish the same thing by pulling the link inwards with a piece of cable.

If you’re working on a chain in place, a chain hook can help you keep the two ends in place and under stress.

How To Shorten A Bike Chain With A Chain Tool: A Step-By-Step Guide

how to shorten bike chain diy guide

Here’s how to use a chain tool to shorten a chain step by step:

1)    Determine The Proper Chain Length (For New Chains)

You won’t need to calculate the required chain length if you’re mending a chain on the road. To make the fix, you’ll simply remove as few links as possible.

When creating a new chain, you have several options for calculating the required length. You can count the links one by one using a chain-length calculator.

You can lay it beside your previous chain and eliminate any visible additional links.

A third method is to measure chain length while wrapped around your largest rear sprocket and largest chainring on the front.

2)    Find The Master Link (Or Not)

Although it is easy to break the chain and rejoin it with a master link, most of them are not “technically” reusable.

As a result, anytime you need to shorten a chain for whatever reason, you’ll utilize a chain breaker and a new master link to reconnect it.

If the master link is reusable, you can find it before disconnecting the chain and removing a section of it. Unless the repair is near the master link, this does not apply.

3)    Break The Chain

Once you’ve determined where you need to break the chain, lower it over the tools farthest support so it’s braced against the end.

Then, carefully turn the tools handle clockwise until the punch rests on the centre of the chain pin. Continue rotating clockwise to force the pin (or rivet) out of the chain’s far side. The chain has snapped.

“If this is an emergency repair and you do not have a master link with you, do not entirely remove the chain pin. When you hit resistance for the second time, with a small portion of the pin still protruding inside, stop and leave the pin alone. With a little persuasion, you can still break the chain.”

4)    Disassemble The Chain Links

If it is a new chain, you only need to break it once to make it shorter. However, if you’ve removed it from your bike, you’ll have to break it again.

When shortening the chain, be mindful of the ends. If you utilize a master link, they must both be smaller inner half-links since the master link works as an outer-plated half-link connecting two inner links.

Asymmetrical chain ends are required when shortening a chain without a master link or with a Shimano replacement pin.

5)    Reattaching The Chain

The simplest method for reconnecting a chain to a master link is to precisely position it over the pin ends and tighten the chain by rotating the pedals.

To do the emergency fix mentioned in step #3:

After removing a damaged portion of the chain and joining asymmetrical ends together, you must return the half-removed pin to its original location. You’d use your chain tool to do this, laying the chain over the nearest support to the punch.

Move the misplaced pin back through the hole on the far outer plate gradually. Don’t go overboard with this; the pin should just protrude slightly.

If you do this repair on a fully peened, non-reusable chain pin, you will weaken the chain. Replace it as soon as feasible.

Cutting Of Chains With Manual Tools

how to shorten a bike chain

You’ll need the following if you don’t have a chain tool:

  1. Hammer 
  2. Master Link
  3. Small hammer or punch
  4. A pair of nut pliers or a bit of wire
  5. You’ll also need a solid surface to hammer on, such as a workbench or a piece of wood.

If you’re dealing with a fresh chain, you’ll need to determine the optimal length first.

There are two methods for bracing the chain during this procedure. You can use a vice, but this is the easy way:

1)    Search For A Master Link

If the chain is still on the bike, it should have a master link so you may easily remove and rejoin it.

Without a master link, you can still break and shorten the chain, but rejoining it will be more difficult.

If there is a master link, open it with a pair of narrow pliers or a piece of cable.

2)    Break The Chain

Place the nut on a solid hitting surface. Determine which pin you want to remove and place it over the nut. Hammer a nail or punch directly into the centre of the pin.

If the chain is incompatible with master links, do not hammer the pin fully out.

3)    Disconnect The Chain Links

If you’re linking this chain to a master link, the chain ends must be identical thin segments once more. To shorten a fresh chain, you’ll be deleting two half-links (1 whole link) at a time.

Rejoin the chain by pressing the pedals and clicking the master link into place. You’ll have to hammer the pin back into place if you don’t have a master link.

Factors Necessitating That You Shorten Your Bike Chain

Here are the 4 reasons why you should shorten your bike chain.

1)    Definitions Of Links And Sizes

The distance between chain pins is sometimes counted as a link by manufacturers, which is not precisely correct.

A bike chain has one inch between each “correct” link and just half an inch between pins.

2)    The New Chain Is Far Too Long

Chains are naturally sold in regular lengths when manufacturers sell them. These lengths will always be on the long side, so you buy a chain and cut it to size.

“The average chain length is 116 links. That’s the size you’ll find on most boxes, however, the number of links may vary depending on the bike.”

3)    Cassette Replacement

Another way to shorten a chain is to use a cassette with a significantly smaller largest sprocket.

The advantage of lowering the cassette range is that the sprockets are closer in size to each other, resulting in smoother gear changes.

4)    Mechanical Failure

A mechanical situation may compel you to reduce your chain while riding. That’s when having a chain tool available helps a lot; otherwise, you’ll need a lift.

Some Preventions For Your Bike Chain

You can use the following tips to shorten your bike’s chain:

  • Always use a high-quality lubricant to make your chain run more smoothly and extend its durability.
  • Your bike chain may appear immaculate, but cleaning it will reveal the true state of the chain. As a result, cleaning is more vital. This will tell you whether or not the chain needs to be repaired rather than shortened. Sometimes the chains become completely ruined, but if you don’t inspect them by cleaning them, you might not discover them. As a result, it will be a major issue for you.
  • If you ride your bike regularly, you should have a good chain tool because you will be working with your chain more frequently. With the help of a chain tool, you may do your work quickly and efficiently.
  • Although your bike may appear to be in perfect condition, it is best to inspect your bike and its chain more frequently to avoid any problems when riding.
  • If you do not feel comfortable reducing your chain on your own, you should take it to a bike repair shop. This will cost you a little more, but if that’s acceptable to you, go for it rather than doing it on your own.

Final Thoughts

Bike chains can become longer with age and use, or you can buy one that is overly long. You can remove superfluous links, shorten the chain, and make your bike rideable again with a few tools, a bike stand, and a little time.

It is critical to understand how to shorten a bike chain to ensure optimal performance – and hopefully, by now, you do. It’s a straightforward process, and you shouldn’t have to pay someone else to do it for you.

After all, not everyone can be willing to perform this type of self-care. If you don’t like to get your hands dirty and may not have the time, you might just have your local bike mechanic who can do it for you for a few dollars.

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