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Anti-Drop Design

Single speed chains like Z1 and Z1eHX have higher inner plates. These larger plates will prevent the chain from derailing and dropping off when the chain gets worn or set with too much slack.


Special black coating which gives a long lasting bold look, many times more durable than paint.

Read more about our coatings >

Brass Plating

“Gold“ color plating on e.g. Z1, X101

Bullet Pin

A special connecting pin that is used to assemble a chain when a MissingLink is not possible (e.g. halflink chains)

Bushed Construction / Bushed Chain

Bushed chains, also called roller chains, are built in a classic, constructively complex design that is characterised by high running performance and precise chain guidance. Our wide chains (1/8“) e101 EPT, X101 and eCargo1 are produced in this design. The outer link plates sit directly on the pin that holds the chain components together. The inner link plates sit on a bush through which the pin is inserted. The bushing is surrounded by a roller that reduces friction between the teeth of the chainring and sprocket and minimises wear. Because of the lack of flexibility, bushed chains are not suitable for derailleur systems. (1. outer plate, 2 pin, 3. inner plate, 4. bushing, 5. roller)

Bushless/Bushingless Chain

The bushless design is predominant in bicycle chains today. Instead of a simple hole, each hole of the inner plate has a protruding shoulder. The pins that connect the outer plates run directly through the holes of the inner plates and the rollers roll around the outside of the protruding shoulders. Since the „bushing“ of a bushingless chain is made up of two halves that don‘t connect directly with each other, this type of chain is more flexible sideways than a bushed chain and thus suitable for derailleur systems. A bushingless construction also permits the chain to run more smoothly when it is not perfectly lined up with the chainring and sprocket than a bushed chain. (1. outer plate, 2 pin, 3. inner plate, 4. roller)


A cluster of sprockets (5 to 13 pcs) that is mounted on the freewheelbody of the rear hub. Each sprocket has a different number of teeth, enabling the rider to select a suitable gear ratio.

See KMC REACT cassettes >

Chain Checker

A tool which measures the distance or elongation between rollers over 8 links to determine the chain‘s wear.

See KMC tools >

Chain Breaker / Deriveter

A special tool to push out the chain‘s pin, in order to give the chain the needed length.

See KMC tools >

Chain Dimensions

The dimensions of a chain are defined by three variables. There are three common internal dimensions for the distance between the inner plates: wide 1/8“, narrow 1/32“ and super narrow 11/128“. The pitch, i.e. the distance from pin centre to pin centre of a chain link is the same for all common chains with 1/2“. The pin length varies between 5.2 and 9.3 mm and is always adjusted to the total width of a chain (inner dimensions + material thickness of the plates). When choosing a chain, the chain width (1/8“, 3/32“, 11/128“) and the thickness of the chainring and sprocket must always match.

Chain Wear

As the chain is used, its parts wear out due to interaction with the other drive components and external influences. A chain should be replaced before it is heavily worn, as a damaged chain can also damage the other, often much more expensive drive components.

More information >


Chainline refers to how straight the chain runs between the front chainring and rear sprocket. Ideally, chainring and sprocket should be in the same plane. In numbers, chainline is the distance between the centerline of the bicycle frame and the centerline of the chain. If there is a difference between front (crankset) and rear (rear wheel), the set-up isn‘t perfect. The more slanted the chain, the more inefficiently the drivetrain works. For a good adjustment of the drive, we offer our chainrings and drive sprockets with different chainlines.


Edges on the inside of inner and outer plates of the chain are specially shaped to improve shifting and to ensure smoother and more silent running of the chain.

Double X-Bridge

The X shaped design on the outside- and the inside of the outer plate, to improve shifting performance.

Durability Factor

We use this indicator for our upscale chain series (DLC, e-Series, X, XSL, XEL and X101). The number of points indicates the wear resistance of the chain (1 point = normal; 5 points = maximum).


This is a pin especially designed for our e-Bike derailleur chains, in order to cope with the extreme forces applied to the drive train of an e-bike.


EcoProTeQ, this is a silver coloured anti-rust coating, applied on all parts before assembling the chain. It is non-toxic and protects chains from corrosion for twice as long (first signs of rust only appear after 650 hours of salt spray testing) as a conventional rust protection.

Read more >

Half Link / Offset link

Sometimes the length of the chain on an internal geared or single speed bike can‘t be properly adjusted. In this case a half link chain (KMC HL-Series) is the solution to reach the ideal chain tension.

Inner Plate

These are the plates located at the inner side of the chain holding the roller and forming the chain‘s bearing (bushless chains only, flat in case of bushed chains).


The KMC MissingLink is the connecting element for opening and closing your chain easily and safely. Please note whether your chain is fitted with a reusable or non-reusable chain link. A non-reusable link must be replaced after opening, a reusable MissingLink can be opened and closed as often as required, but must be disposed of when the chain is worn out.

MissingLink Pliers

A tool to open or close the MissingLink connecting links. There are 2 types – one for opening, and one for connecting.


These chains are 1/2x3/32“ sized, for single speed/internal geared bikes, but also for derailleur systems up to 8-speed. Chain width varies from 7.0–7.8 mm. Matching chainrings and sprockets have approx. 2 – 2.3 mm tooth thickness.


Narrow-Wide is a new type of tooth profile for chainrings in which narrow and wider teeth alternate. The idea behind it: a more stable toothing of chain and chainring or sprocket.

The solution is primarily aimed at specific problems with 1x systems (one by, one chainring at the front and 8 to 12 sprockets at the rear), where the chain lines have become extreme. A look at the details of a chain reveals the problem. The distance between the inner plates is smaller than the distance between the outer plates. On a conventional chainring, the width of the teeth is chosen so that the teeth fit into the space between the inner plates. This inevitably leads to greater play in the wider outer plates. With Narrow-Wide, on the other hand, the space between the plates is perfectly filled and the drivetrain is less susceptible to chain drop.


This means that our chains do not have a prescribed mounting direction.


Nickel Plated, this coating gives KMC chains their silver coloured look.

Number of Links - Chain Length

Usually the chain length is determined by the number of links. Each pair of inner or outer plates count as a link. The length of our offered chains ranges from 112 to 126 links and depends on the gear type and number of gears (derailleur). For assembly, the intended chain must be shortened to the correct length.

Outer Plate

These are the plates on the outer sides of a chain, whose design details such as the bevel and X-Bridge have a significant influence on the running properties of a chain.


The pin is the part of the chain (a small rod) which connects the inner plates to the outer plates

Pin Power

The force required to push a rivet/pin out of a chain. The better the riveting, the higher the pin power.


Rust Buster, first generation of rust protection, zinc treatment and in use at models in our B- and S-Series. Now almost completely replaced by EPT.


The work step in chain production in which the pin is connected to the outer plates. Applying pressure deforms the tip of the pin and creates a connection that holds the individual parts of a chain securely together.


The metal ring mounted in each inner plate, it interacts with the sprocket (s) and chainring (s).

Shield Tech

Shield Tech by KMC is the patented riveting process behind the e-Pin. The cold forged pins have a larger diameter (+10%), are significantly stronger with 450 kgf pin force and the flatter shaped pin heads reduce friction.

Single Speed

For the drive train, usually internally geared (hub) systems are grouped as „single speed“ – a term derived from the fact that hub gears have only one chainring at the front and one sprocket at the rear. Today, however, single speed is usually understood to mean a type of bicycle in which the gears are deliberately omitted.


The KMC Snap-On is a connecting link for certain chains used for single speed/internal geared bikes.


The sprocket is the rear element of the drive train. The number of teeth influences the transmission ratio of the drive. The thickness of the sprocket and the dimensions of the chain (wide 1/8“, narrow 3/32“ or super narrow 11/128“) must be matched.

Super Narrow

Chains for derailleur systems 9-, 10-, 11- and 12-speed are super narrow 1/2x11/128“ sized. The width of these chains varies from 5.2 to 6.6 mm. Chainrings and sprockets must not exceed 1.9 mm thickness in order to fit into the chain‘s inner links.


The Titanium Nitride coating is used to give the chain its distinctive gold colour, also the surface is slightly smoother than other coatings.

Torsion Resistance

The ability of a chain to withstand torsion. A derailleur chain is subject to high torsion, especially during shifting. Mid motors of e-bikes do apply a lot of power, so extra torsion resistance is required. Torsion resistance is increased by special riveting technique, Shield Tech and e-Pins.

Wear – Elongation – Stretch

These terms refer to the extent to which a chain or related part of the drive train is down.

Wide Chain

Wide chains are 1/2x1/8“ sized and only for single speed/internal geared bikes. The overall width varies from 8–10 mm. Matching chainrings and sprockets have 3 mm tooth thickness.


The X shaped design on the outside of the outer plate, to improve shifting performance.


The features of the X-series, as a lightweight version thanks to stamped inner and outer plates, available for 10-speed and 11-speed rear derailleurs.

See products >


The features of the X-series, as a extra lightweight version thanks to stamped inner and outer plates and hollow pins, available for 10-speed and 11-speed rear derailleurs.

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Super Light X-Series, currently our lightest chains, with slotted inner- and outer plates and hollow pins, available in 9-, 10- and 11-Speed.

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