Motorcycle Chain Corrosion Issues

Although there are areas of a motorbike that can suffer from corrosion, one of the most common and also most critical surrounds the bikes chain.

A motorcycle chain tends to rust because the metal has been exposed to a combination of moisture and oxygen. Whilst this cannot be stopped, it can be minimised through regular maintenance.

In fact, neglecting basic maintenance can exacerbate issues, especially when riding in rough conditions such as wet, salted roads.

Ensuring you observe a regular cleaning and lubrication schedule of your chain will work wonders in preventing corrosion.

Unpicking the term ‘Corrosion’

According to The Cambridge Dictionary, corrosion is a process in which a solid, in this case the metal on your chain, is eaten away and changed by a chemical action.

This action occurs in the oxidation of iron, through the presence of water by an electrolytic process. It is usually a slow process of deterioration by being eaten or worn away. It shares similarities to abrasion but tends to cause more damage over a shorter period of time.

Types of Corrosion

Whilst you don’t need to know the chemical process that leads to corrosion, it is crucial to know the warning signs. You also need to know the distinct types and levels of disrepair corrosion can cause if you are going to take the proper corrective action.

The main forms of corrosion within metals tend to be classified as: Atmospheric, Erosion, Selective, Uniform, Pitting, Fretting, Stress, and Inter-granular corrosion.

All of which can be spotted by the naked eye and just a little bit of knowledge (knowledge we aim to give you today)

Your chain – the main driving force behind it all

There are several ways a motorcycle receives power from the engine. That power can either come from a chain, a belt, or a shaft.

Chain driven motorcycles are by far the most common type of drivetrain found on the roads today. If you do not maintain your chain properly it will gather dirt, debris, water, salt, humidity, and other foreign bodies that hinder its performance.

These will all result in the chain rusting. This not only affects the motorcycles performance, but also reduces the chain life significantly as a whole.

Motorcycle chains, although simple mechanisms, still require frequent, simple maintenance checks. Because they are so vital to the function of the motorcycle, they require prompt attention when anything unusual happens to them, such as corrosion (starting with visible rust).

Types of motorcycle chains

Chains usually come within in two categories: unsealed or standard roller chain and sealed or O-ring chain. Unsealed chains are commonly found on vintage bikes, small-displacement economy rides and off-road motorcycles. They are what you see on bicycles and conveyor belts, and even the treads on a bulldozer are a type of unsealed chain.

Standard chain is just a series of plain bearings made of metal links and nothing else. That means it is up to you to apply lubricant to keep the parts from grinding themselves into dust, and you have to do it frequently.

Even then, reducing friction between high-wear components like the link pins and bushings is difficult, and as a result unsealed chains wear quickly, necessitating frequent slack adjustments and replacement.

Sealed chains, as the name suggests, have rubber seals sandwiched between the side plates and inner links, sealing in grease that is sucked in around the pins via vacuum when the chain is manufactured.

The O-rings seal the grease in and keep dirt and water out, ensuring the pins and bushings are bathed in lube, which reduces wear and extends the life of the chain. This arrangement also means less frequent and lighter applications of chain lube, since all you are doing with that can of aerosol is keeping the O-rings moist and pliable and preventing the metal links from corroding.

What causes your chain to corrode?

Being a motorcycle enthusiast, you will be aware of the many factors constantly at play when riding, working on, and maintaining your bike chain. A part of your regular maintenance checks absolutely must include a close examination of the chain. By the time it has started to turn a discoloured orange colour, the damage has been done as rust has set in.

The rust absolutely needs to be dealt with whilst it is still only functioning on a surface level. If it starts to deepen into the chain, it will unfortunately need to be fully replaced.

Being mindful of what causes your chain to corrode will minimise the possibility of needing a full chain replacement.

The main causes of corrosion are:

Chain metal has been exposed to a combination of moisture and oxygen.
A lack of maintenance including regularly cleaning and lubricating the chain
Riding the motorcycle in rough conditions such as wet, salted roads.
Ignoring the start of rust spots being visible within the chain
Living in a humid area – exasperates the corrosion process
Salt damage building up over time
Using sub-standard cleaning materials – quality is needed
Ineffective lubrication (a lack of penetration into the chain round parts)
Severe wear of pin and bush surfaces

Damaging implications of corrosion

As you already know, when encountering any motorcycle chain issues, each issue in isolation can affect your motorcycle’s power, efficiency, speed, and heritage. At Renold, these are all intrinsic qualities that we deploy into every motorcycle chain we design and manufacture.

However, as with every complex piece of technology, there are potential concerns that can arise that we classify under the umbrella of ‘corrosion’ related issues.

If there are corrosion issues occurring within your motorcycle, you may notice one or more of the following symptoms:

Discoloured spots of rust within and on your chain
A rusted (corroded) chain can slow your bike down, losing 25 – 30% of the performance and speed of your bike
Affected gear shifting and can even lead to permanent damage of the drivetrain
Possibility of it snapping, especially if you’re applying too much pressure to your bike pedals
Compromised chain integrity, as it cannot take the tension as you pedal like it usually would
Losing overall control of your motorcycle
Additional friction being caused, which places wear on your other drivetrain components, and makes the chain more susceptible to breakage

Later symptoms of corrosion related issues (when the issue has been left untreated and therefore worsened):

Heavy corrosion and erosion of the chain as a whole (needing an immediate replacement)
Severe corrosion of material from areas of the chain leading to vast weakening and tensile failure - Tensile strength is defined as the “resistance to lengthwise stress, measured by the greatest load in weight per unit area pulling in the direction of length that a given substance can bear without tearing apart” (Webster's New World Dictionary of the American Language, 1959)
Irreparable damage to the more expensive components within your motorcycle
Being unable to ride the motorcycle, due to the corrosion occurring within the chain – total failure and needing to replace with a new one

Many of the above can result in your chain becoming worn-out altogether and your motorcycle unrideable. As always, prevention in the form of regular maintenance checks is something you absolutely must action as a priority.

Preventing corrosion

There are many advisable courses of action to prevent, irradicate and stop any corrosion issues. Of course, your chain being made of metal will always be susceptible to corrosion, but maintenance should minimise this as much as possible.

Undoubtedly, the most efficient way to prevent motorcycle chain rust is lubrication. This adds a protective seal to the metal chain so moisture cannot penetrate the surface.

You should also get into the habit of cleaning and drying off your metal chain at the end of each ride. As tedious as this may sound, you will be saving yourself valuable time and costly investments in the future.

Further information on lubricating your motorcycle chain can be found on the Renold Lubrication advice page.

Regular chain maintenance should be a part of your motorcycle maintenance routine. A motorcycle chain should be lubricated and its tension checked every 4,000 miles or every six months, whichever comes first.
Thorough, regular cleaning of the chain, as well as the other components of your motorcycle
Oil is the most common effective lubricant and for the majority of applications a non-detergent, petroleum based, multigrade SAE 20/50 oil would be suitable.
You can try respraying rust spots until any remaining rust has been removed
The use of Kerosine – as it is natural, affordable, and one of the best alternatives on the market for expensive branded products (budget depending)

Maintenance is key

Regardless of the potential occurrence of corrosion, you should lubricate your chain every 400 to 500 miles or at least once every month, as well as performing regular maintenance checks to avoid the issues listed above. Especially if you ride your motorcycle frequently, you absolutely must prioritise maintaining it.

When you visibly see orange rust patches on your motorcycle chain, this tends to be too late for any real preventative, successful action.

At best, you have surface rust. However, the worst-case scenario is the rust actually runs much deeper than at a surface level. To reiterate, this would result in a brand-new chain being necessary, just to be able to safely drive your motorcycle.

Understanding how and when to take preventative actions

Here at Renold, we want to help you diagnose any potential chain concerns in as short a time as possible. We recommend that the quickest way to check the status of your drive chain is to get on your hands and knees and physically inspect it from a close-up angle.

While chain wear is absolutely normal and to be expected, correct maintenance reduces the impact of these factors and dramatically increases chain life. It is a common misconception that rust can simply be wiped off a chain and the chain will then return to its former self, Unfortunately, this is not the case, as the damage is much more than the visible patches you can see.

Chain corrosion (rust) weakens the components of the chain, the steel. This means that the longer rust remains, the weaker your bike chain will get. Although this may happen gradually, it worsens over time. Corrosion can start to take place within 4 days of a motorcycle being left in non-ideal locations.

At this point, your only option is to replace the chain altogether.