Transmission Chains

A bicycle's drive chain is one of the key components of the drivetrain, transferring power from the pedals to the rear wheel, propelling the bicycle forward. It's a crucial component for the bike's operation, requiring maintenance and care to ensure smooth and safe pedaling. Here's an overview of how it works, how to choose the right chain, and how to keep it in good condition.

Function of the drive chain

The drive chain transfers the force the cyclist exerts on the pedals to the rear wheel through the movement of the sprocket and chainring. This process occurs thanks to the chain's teeth , which engage the teeth of the front chainrings (on the pedals) and the rear sprockets (on the hub). The combination of chainrings and sprockets allows the cadence and pedal resistance to be varied, depending on the type of terrain and the desired speed.

Main components of the drive chain

Chain :

The chain is made up of a series of links connected by pins and plates. The links are usually made of steel or reinforced materials such as titanium (for high-end racing bikes).

Chains differ in the number of links and the type of scaling : chains for racing bikes, mountain bikes, city bikes, etc.

Crowns :

Chainrings are the toothed components found on the front crankset. Depending on the type of bicycle, the chainring can be single (on racing bikes) or multiple (on mountain bikes or trekking bikes).

Sprocket (or cassette) :

The sprockets are located on the rear hub and are a series of gears that allow the cyclist to change gears. The combination of sprocket and chainring determines the pedal resistance.

Derailleur :

The derailleur is a component that moves the chain from one chainring to another (front) or from one sprocket to another (rear), allowing gear changes.

Shift wires :

Shift cables are connected to the derailleur and are pulled or released by the rider via levers on the handlebars to change gears.

Types of transmission chains

Bicycle chains vary depending on the type of bike and the drivetrain. The main differences are the number of speeds and the type of teeth:

Chains for racing bikes :

Road bike chains are generally thin and designed for a high number of gears (9 to 12 speeds). They have narrower links to ensure smooth and precise operation.

They are often made from lightweight, durable materials to reduce the overall weight of the bike.

Mountain bike chains :

Mountain bike chains are more robust and often wider to withstand harsh conditions like mud, dust, and rocks. They can be designed for 9-, 10-, or 11-speed drivetrains.

They often feature reinforced links for greater durability and stress resistance.

Single speed bicycle chains :

Fixed-speed or single-speed bicycles use simpler chains, as they don't require a gear shifting system. These chains are usually wider than those on bicycles with derailleurs.

Chains for electric bicycles (e-bikes) :

E-bike chains are designed to withstand the additional stress generated by the electric motor. They are therefore more durable and reinforced.

How to choose the right drive chain

Compatibility with the number of speeds :

It's crucial to choose a chain that's compatible with the number of speeds on your drivetrain. A 9-speed chain won't work properly on a 10- or 11-speed system. Check the number of speeds on your drivetrain (e.g., 9, 10, 11-speed) to ensure you're choosing the right chain.

Chain length :

Chains must be cut to the correct length based on the type of bicycle and drivetrain configuration. A chain that's too long or too short can compromise gear shifting and derailleur operation.

Materials and resistance :

Choose chains made of durable and resistant materials, especially if you plan to ride on difficult terrain or if your bike is e-bike. Carbon steel or heat-treated chains are often chosen for their durability.

Brand and quality :

Choose chains from trusted brands like Shimano, SRAM, Campagnolo, or KMC, which offer high-quality chains designed to ensure precise and long-lasting operation.

Drive chain maintenance

Proper chain maintenance increases the lifespan of your bike and ensures a smoother ride. Here are some tips for keeping it in good condition:

Regular cleaning :

Clean the chain by removing dust, mud, and debris. Use a chain degreaser and a brush to clean the links. Avoid using abrasive products that could damage the chain.

Lubrication :

Apply a chain oil after cleaning. A well-lubricated chain reduces wear and ensures smoother shifting. Use quality chain oils, preferably water-resistant, if you ride in wet conditions.

Check and replacement :

Check your chain periodically for signs of wear. A stretched chain can impair gear shifting and damage the sprocket or chainring. Use a chain wear gauge to determine when it's time to replace it.

Conclusion

The drive chain is an essential component for the proper functioning of your bicycle. It's important to choose the right chain for your bike type and drivetrain, as well as keeping it clean and lubricated to ensure its longevity and performance. Proper maintenance will ensure a more pleasant, smooth, and safe ride.