What is rust and corrosion and how can it be prevented?

If you do not take steps to protect your bike from the elements, certain parts are likely to start to corrode or rust. This can result in components either needing a lot of restorative work or replacing altogether. All of this can be avoided with some simple preventative action to stop rust from ruining your bike.

As well as looking unsightly, rust and corrosion can also affect the structural integrity of the component in question. In the early stages it can be simple surface rust or corrosion that can be removed with a rust remover or a wire brush.

However, for areas that have been untreated for a long period, it is likely that the issue will have travelled deeper into the material. If you are ever in doubt about the safety of a corroded part it is always best to replace it rather than risk it failing during a ride.

• Read more: How you might be damaging your bike when you clean it

What is rust?

Rust is not necessarily the same thing as corrosion. In fact, rust is the common name given to a type of corrosion that occurs in materials that contain iron. The brown substance we know as rust is a byproduct of a chemical reaction between the iron in the material and oxygen in the air that is catalysed by water. The chemical compound we know as rust is formally known as iron oxide.

Rust can only occur in components made of materials containing iron, which means aluminium, titanium and carbon fibre won’t rust. Steel on the other hand does contain iron in varying quantities. This means that steel components such as chains, bolts and bearings are all susceptible to rust.

What is corrosion?

Just because components that contain no iron cannot rust does not mean that they are out of the woods. As mentioned before, there are many kinds of corrosion. Another form of corrosion can occur in very similar circumstances with aluminium, when it comes in to contact with oxygen and water. In this case, the byproduct is aluminium oxide.

• Read more: How to protect your bike while turbo training

What is the easiest way to prevent corrosion?

The common theme across rust and general corrosion is the need for moisture to catalyse the process. The easiest way to prevent your components from suffering is by keeping them dry. This does not mean never getting them wet or only riding when the sun is out but it does mean making a conscious effort to dry the bike and components after a wet ride or after the bike has been cleaned. The drier the bike the less likely it is for corrosion to develop.

• Read more: The best ways to get your bike ready for winter

Ideally, you can keep your bike somewhere warm and dry, like inside a house, but even if it’s stored under cover outside or in a garage, it should be okay if you are meticulous about drying your bike, especially in the harder-to-reach areas such as the headset bearings and the inside surfaces of the chain.

How can I protect hard-to-reach components from corrosion?

There are some parts of the bike that even with the best intentions in the world are going to be close to impossible to fully dry out. In these cases, prevention is the best plan of action. Using bike-specific grease can act as a barrier that will prevent any moisture from making contact with the component in the first place.

A grease barrier is great but it will not last forever and every few months it is worth giving these areas of your bike a strip down to clean them up and replace the grease. Although this can be extra work, it will prolong the life of your expensive components.

• Read more: How to clean your bike effectively in 5 minutes

The area most prone to rusting is the chain of a bike. This is because it is so exposed to the elements and can often have any protective lubricants washed away by persistent rain or standing water. In regards to protecting the chain from rust, an oil-based lubricant will perform better than a wax lubricant. On long or especially wet rides it can be worth taking a small bottle of oil-based lubricant with you to top up the chain as and when it gets washed off.

• Read more: How to make your drivetrain last longer

Important places to check for corrosion

Not all areas that are susceptible to corrosion are as obvious as the chain, so it is important to routinely check these other areas over. Indoor training is the perfect environment for corrosion to take hold of your bike and components. The moisture and salinity of sweat can cause accelerated corrosion. Checking areas like your lever clamps, seat post, headset, and all bolts (unless titanium) and thru-axle threads can prevent expensive damage that could have been prevented.

• Read more: How to create a maintenance log for your bike using Strava

Keep your frame protected

Bikes that are built around a metal frame whether that be steel or aluminium need to be protected from corrosion. The most common method manufacturers do this is by painting the frame. Of course, this is part of the aesthetic of a bike too, but its primary purpose is to protect the frame from corrosion. This means that if you find that the paint on the frame is starting to flake off or has been scratched away to the point you can see bare metal it needs to be touched up with some paint or nail varnish.

For some more quick-fire facts and debunked myths make sure to check out the video linked at the top of the page where Alex goes through some of the common questions he gets asked about rust and corrosion.

For more on bike maintenance make sure to check out our 'How to' section on bike maintenance where you can find easy-to-follow guides for just about everything you might need to do to your bike.