Bicycle Quick Link Chain Removal/Installation and Chain Length Calculation

Introduction: The Quick Link Is One of the Greatest Small Inventions

Before the quick link (also called a Missing Link) existed, removing a chain required a chain breaker, and every removal damaged a pin. Now, with quick links, removing and installing a chain is almost as easy as buckling a belt — well, not quite that easy, but at least no special tool is required.

However, convenient as quick links are, installing them backward, using the wrong specification, or ignoring the reuse limit can all cause a chain failure while riding. Today we’ll go through a complete guide to quick link chain removal/installation and chain length calculation.

Quick Link Basics

What Is a Quick Link?

A quick link consists of two symmetrical metal plates, each with one pin and one hole. When the two plates are interlocked and pulled taut, the pins lock into the narrow section of the holes, forming a secure connection.

Quick Link Brands and Specifications

Speed Must Match!

Golden rule: The quick link speed rating must exactly match the chain speed rating. Do not mix and match!

Quick Link Installation Guide

Preparation

1. Confirm that the quick link specification matches the chain speed
2. Confirm the chain length is correct
3. Confirm both ends of the chain are inner links (the side with the hole)

Installation Steps

1. Thread the chain through the drivetrain: through the chainring, rear derailleur pulleys (guide and tension pulleys), and cassette
2. Bring the two ends of the chain together: confirm both ends are inner links
3. Insert the two quick link plates into each end of the chain:
   • The pin on each plate passes through the inner link hole on the opposite end
   • The two quick link plates interlock
4. Pull the quick link taut:
   • Method 1: Grip both sides of the quick link by hand and pull the ends apart
   • Method 2: Place the chain on the chainring, brake the rear wheel, and press hard on the pedal (the simplest method)
   • Method 3: Use quick link pliers
5. Confirm it’s locked: Listen or feel for a “click” as the pins seat into the narrow slots

Installation Direction

Some quick links have a required installation direction:

• KMC: Some models have a directional marking, with the arrow pointing in the direction of chain travel
• Shimano: The side with the printed marking faces outward
• SRAM: Usually no directional restriction

How to confirm: After installation, turn the crank and observe whether the quick link passes smoothly through the front and rear derailleurs. If there’s binding, it may have been installed backward.

Quick Link Removal Guide

Removing by Hand

1. Locate the quick link (turn the crank until the quick link is above the chainring)
2. Pinch the two plates of the quick link between the thumb and index finger of each hand
3. Push the plates toward each other while pulling diagonally apart
4. The two plates of the quick link separate

Honestly: Removing a quick link by hand takes a fair amount of strength and technique, especially for 11-speed and 12-speed quick links, which are very tight.

Removing with Quick Link Pliers

Quick link pliers (Missing Link Pliers) are the most recommended tool:

1. Align the two tips of the pliers with the pins on each plate of the quick link
2. Squeeze the pliers
3. The quick link releases automatically
4. Extremely simple, and can be had for around NT$200

Quick Link Reuse Limits

Official Recommendations

Real-World Experience

Many riders (and shop mechanics) reuse quick links that are officially rated for single use. On drivetrains of 10-speed or fewer, this is usually not a problem. But 11-speed and 12-speed quick links, being narrower, carry a higher risk when reused.

Recommendation: If the quick link is a safety-critical part (long-distance touring, racing), use a new one. For everyday commuting, reusing it 2-3 times is generally acceptable.

Chain Length Calculation

Why Does Chain Length Matter?

• Too long: The chain goes slack and may hit the chainstay when in the small chainring/small cog combination
• Too short: The chain becomes overly tight in the big chainring/big cog combination, which can damage the rear derailleur

Method 1: Big-Big Method (Most Common)

1. Route the chain around the largest chainring and largest cog
2. Do not route it through the rear derailleur
3. Pull the two ends together
4. Add 2 full links (1 inch) at the point where they meet
5. This is the chain length you need

Method 2: Old Chain Comparison Method

1. Lay the new chain alongside the old chain
2. Confirm the old chain’s length was correct (it worked fine previously)
3. Cut the new chain to the same length as the old chain

Note: An old chain has stretched and become longer, so compare by link count, not by physical length.

Method 3: Shimano’s Official Recommendation

Cutting the Chain

1. After calculating the length, cut it with a chain breaker
2. Make sure both ends are inner links (the quick link needs to connect the inner links at both ends)
3. When cutting, push the pin all the way out
4. Check that the inner links at the cut ends are not deformed

Frequently Asked Questions

Q: Can a quick link be installed at any position on the chain?
A: Yes, but it’s best to avoid positions that flex frequently (for example, where the chain passes over the derailleur pulleys).

Q: What should I do if a quick link breaks while riding?
A: This is exactly why you should keep a spare quick link in your saddle bag. If you have neither a spare quick link nor a chain breaker, you can temporarily splice the chain with thin wire (only for a slow ride home).

Q: Is it normal for a quick link to make noise?
A: A light “click” as the quick link passes through the front or rear derailleur is usually normal. But persistent noise may indicate incorrect installation.

Q: Can quick links of different models from the same brand be mixed?
A: As long as the speed rating matches, yes. For example, a KMC 11-speed quick link can be used with a Shimano 11-speed chain. But it’s best to use a quick link from the same brand as the chain when possible.

Q: Does a new chain always need a new quick link?
A: It’s recommended. Pairing a new chain with an old quick link can result in uneven wear between the pins and holes, which may not be secure enough.

Practical Tips

1. Spare quick link: Always keep a spare quick link in your saddle bag
2. Quick link pliers: Invest in a pair — a NT$200 tool saves a lot of hassle
3. Keep a record: Note down your chain speed and quick link model
4. Check regularly: Occasionally glance at the quick link before a ride to make sure it looks normal
5. Replace the quick link with the chain: Don’t skimp on this small cost

Conclusion

Quick links make chain removal and installation fast and simple, but correct usage and spec selection still matter. Once you’ve mastered quick link installation and removal, along with correct chain length calculation, you’ll be able to handle most chain issues yourself.

Remember: a spare quick link and a pair of quick link pliers in your saddle bag may be some of the most valuable tools you carry.

Related Reading

• Chain Length Calculation and Installation: The Drivetrain Setup Beginners Get Wrong Most Often
• Chain Wear Measurement and Replacement: Key Knowledge for Extending Drivetrain Life
• Guide to Chain Tools and Multi-Tools: Essential Gear for On-the-Go Bike Repairs
• Confirming Correct Installation and Safety of Front/Rear Quick-Release and Thru-Axles