Renold - Troubleshooting Guide: Pitting Corrosion

Are you having trouble with your motorbike chain? Does it seem to be corroding or pitting prematurely? If so, you're not alone. In this guide, we'll look at what causes pitting corrosion and offer tips on how to fix it. 

We'll also discuss some of the available Renold replacement parts that can help prevent or fix the problem. So, whether you're a casual rider or a hardcore racer, keep reading for information on how to resolve pitting corrosion issues with your Renold chain.

Pitting Corrosion - What is it?

Pitting corrosion is a localised form of decay by which cavities or "holes" are eaten into the metal. Pitting is considered more dangerous than uniform corrosion damage because it is more difficult to detect and predict. 

Pitting tends to occur in areas where the oxygen concentration is low, such as in crevices and under deposits. In stainless steel, pitting can also occur near welds. 

Preventing pitting corrosion requires careful control of the environment and regular inspection for early detection. Surface finishes that minimise crevices, such as smooth surfaces and rounded edges, can also help reduce the risk of pitting corrosion. In some cases, inhibitors can be used to prevent or slow down the process. 

Pitting corrosion can be difficult to repair once it has started, so preventing it from happening in the first place is the best way to protect your motorbike chain.

What Causes Pitting Corrosion?

Pitting corrosion is caused by a local loss of the metal surface's passive layer. This can be due to chemical or electrochemical reactions or the result of physical damage to the surface. Once the passive layer is breached, the metal is exposed to the environment and is subject to attack. Pitting corrosion can occur in ferrous and non-ferrous metals, but it is more common in stainless steel and other chromium alloys.

Pitting corrosion is often challenging to detect because it occurs beneath the surface of the metal. However, if left unchecked, it can eventually lead to structural damage and failure. As such, taking the extra time to check for signs of pitting when examining your chain is essential. 

Take special care to check for the following;

  • Small pits or craters in the surface of the chain
  • Discolouration
  • Flaking or peeling of the metal

Pitting corrosion can be prevented by maintaining a clean and dry surface, using corrosion-resistant alloys, and protecting the metal from physical damage. In some cases, coatings or cathodic protection can be used to provide additional protection against pitting corrosion.

What Can I Do to Stop Pitting Corrosion Within My Motorbike Chain?

Bike chains are particularly susceptible to pitting corrosion due to their constant exposure to moisture and dirt. Pitted areas on a chain can cause the chain to break, potentially leading to a crash.

Ways to prevent pitting corrosion:

  • Clean and lubricate your bike chain regularly.
  • Inspect your bike chain for signs of deterioration and replace it if necessary.
  • Use a quality chain lube.
  • Avoid riding in wet or salty conditions.
  • If you must ride in wet or salty conditions, rinse your chain with fresh water after.
  • Wax your bike chain to protect it from the elements.
  • Keep your bike clean to prevent dirt and grime from building up on the chain and causing corrosion.
  • Store your bike indoors during winter to protect it from road salt and other corrosive materials.
  • Have your bike professionally serviced regularly to ensure that all parts are in good working order.

What Can I Look Out for to Stop Pitting Corrosion?

To stop pitting corrosion, you need to look out for the following:

  • Chlorides: Chlorides are one of the most common causes of pitting corrosion. They can come from seawater, de-icing salts, or even some cleaning agents.
  • Moisture: Moisture is another essential element for corrosion to occur. Water provides the perfect environment for corrosion to take place by providing both a source of oxygen and a way for ions to move through the metal.
  • Acids: When acids come into contact with metal, they break down the protective oxide layer on the surface of the metal, exposing it to further attack.
  • Temperature: Higher temperatures can lead to increased rates of corrosion. This is due to higher temperatures increasing the rate at which chemical reactions take place.

As you can see, there are many factors to consider when it comes to pitting corrosion within bike chains. It is vital to be proactive and monitor your chain regularly to avoid this type of damage. 

If you do find signs of pitting corrosion, take action immediately by cleaning and lubricating your chain. With proper care, you can keep your bike in top condition for years to come.