Shimano TL-CN42 Road and Mountain Bike Chain Wear Indicator - Y12160000

The TL-CN42Shimano is a professional chain wear tester designed to accurately assess the condition of a bicycle chain. Product code Shimano Y12160000, this tester enables cyclists and mechanics to quickly check whether a chain is still in good condition or needs replacing.

Chain wear is not just a visual issue. As the chain accumulates kilometres, the joints between the links gradually develop play. This wear increases the effective length of the chain and can accelerate wear on the cassette and chainrings.

The TL-CN42 therefore enables regular checks to be carried out before wear becomes a problem. It is particularly useful on modern drivetrains, where the cost of a cassette and chainrings can be significant.

Thanks to its ‘ Shimano ’ design and its shape, which has been specifically engineered for checking chains, the TL-CN42 is a compact and easy-to-use tool, suitable for both professional workshops and home use.

Key features of the TL-CN42 Shimano

• Shimano chain wear checker.
• Manufacturer’s reference Y12160000.
• Model TL-CN42.
• Measures chain stretch and wear.
• Quick and easy to use.
• Helps prevent premature wear of the cassette.
• Suitable for road and mountain bike drivetrains.
• Also suitable for gravel, trekking and city bikes.
• Compact and easily portable tool.
• Shimano -designed for drivetrain maintenance.
• Ideal for regularly checking the condition of your chain.

Why check your chain for wear?

The chain is one of the most heavily used components in a bike’s drivetrain. With every turn of the pedals, the links and their pins are subjected to significant stress.

Over time, the joints wear out. This wear and tear causes what is commonly known as chain stretch. In reality, the chain plates do not stretch: it is mainly the wear on the pins and rollers that increases the chain’s overall length.

A chain that is too worn may not engage as effectively with the teeth on the cassette and chainrings. If left on the bike for too long, it can contribute to accelerated wear of these components.

Regular checks using a tool such as the TL-CN42 therefore enable you to take action at the right time.

How do you use the TL-CN42 chain Shimano?

Checking the chain is very simple.

1. Position the bike so that you can easily access the chain.
2. Position the TL-CN42 checker between the chain links as indicated on the tool.
3. Check the position of the tool in relation to the links.
4. If the gauge fits into the mark corresponding to the wear level, the chain should be checked more carefully or replaced in accordance with the specified limit.
5. If the chain exceeds the recommended wear limit, replace it.

To ensure an accurate measurement, it is best to carry out several checks on different sections of the chain.

Why replace a worn chain?

Replacing a chain at the right time generally helps to minimise wear on the more expensive components of the drivetrain.

A worn chain can, in particular, lead to:

• less precise gear changes;
• noises from the transmission;
• a less smooth ride;
• accelerated wear of the cassette;
• premature wear of the chainrings;
• in some cases, the chain jumping off under heavy load.

The cost of a wear indicator is therefore very low compared to the premature replacement of a cassette and chainrings.

Road, mountain bike, gravel: which bikes is it suitable for?

The TL-CN42Shimano is a tool designed to check the wear on bicycle chains and can be used across a wide range of disciplines.

It is particularly useful for:

• road bikes;
• mountain bikes;
• gravel bikes;
• trekking bikes;
• touring bikes;
• bikes used on a daily basis.

The more the drivetrain is used, the more important it is to check the chain for wear regularly.

Workshop tip: don’t just carry out a single check. A chain may show slightly different levels of wear in different areas, particularly if it has been used for a long time in tough conditions. Take several measurements whilst gradually turning the drivetrain.

Another tip: after replacing a heavily worn chain, check the cassette carefully. If the cogs are already badly worn, a new chain may cause the chain to skip on certain sprockets under load.

Technical specifications