What Rain Does to Motorcycles

Is it OK to leave a motorcycle out in the rain? Will rain damage a motorcycle? These are two surprisingly common questions posed by motorcycle owners, with good reason.

While the answer to the former could simply be “no,” and the answer to the latter could simple be “yes,” there’s a little more to it. Obviously rain can rust exposed metal parts (more on that later), but it’s the not-so-obvious components that can also be affected which make these questions worthy of digging a little deeper. 

Water Damage from Prolonged Exposure to Rain

Sooner or later your motorcycle is going to get rained on. However, a little rain won’t damage your bike, as motorcycles are designed to withstand all kinds of weather conditions. 

Water damage to a motorcycle can happen as a result of prolonged exposure to rain and humidity, which causes corrosion, most notably rust. Electrical components and other parts sensitive to corrosion are manufactured to withstand rain. But leave a motorcycle out in the rain long enough and even sealed components will start to corrode. 

Everything from electrical connections to metal parts can suffer rain damage, including brakes, batteries and even the engine itself. And while it’s always a good idea to dry off your bike after riding in the rain, it’s not enough. Rain starts to penetrate as soon as it hits, but short-term exposure won’t do much harm. It’s leaving the water on the bike that does the real damage. 

Rusting

As mentioned earlier, rusting is the obvious negative effect of exposure to rain. If you notice even a tiny rust spot anywhere on your bike, you need to tackle it immediately before it gets worse, as that type of corrosion spreads quickly. 

Inspect your motorcycle for rust spots often. Metal parts on a motorcycle are especially vulnerable to rain. Riding your motorcycle often helps shed water off and keep parts lubricated, but not doing anything after riding in the rain is where you’re asking for trouble.   

Prolonged exposure to rainwater can corrode the chain and sprockets, so cleaning and lubing them is crucial, especially after rainy rides. Other components vulnerable to rusting include bearings, bolts, forks, swingarms, and anything else metal, visible or otherwise. 

It’s not just metal parts either. Besides the aforementioned electrical components, headlights, instrument panels, mirrors and fairings can be affected by prolonged exposure to rain. Even engine parts like the carburetor can get damaged and cause the engine to seize if water gets in them. In other words, your entire motorcycle should be protected from rain. 

How to Prevent Rain Damage

For starters, clean and lube your motorcycle’s chain regularly, as lube helps keep water and dirt off the chain. Give your motorcycle’s brakes a good scrubbing as well. You should be washing your motorcycle regularly anyway, but pay special attention to anything that’s vulnerable to corrosion. Use a water spot remover and a corrosion blocker spray on metal, fiberglass and painted surfaces for additional rust protection. 

Anti-seize lubricant is also great for protecting nuts, bolts and any other exposed metal parts from getting corroded. If any rust has already formed on metal, make sure to clean it off right away. Use a metal polish like Simichrome to restore the metal if rust has settled in. 

Other Types of Rain Damage

Besides rust, unattended water penetration can create other types of corrosion like mold and gunk in your motorcycle’s cooling system. If water collects inside and corrodes the cooling system, it needs to be flushed. 

Likewise, water buildup can rust and gunk up the fuel tank and other fuel system parts like fuel lines, which will create all kinds of headaches and may lead to having to clean and/or rebuild the carburetor. We can go on and on about what other parts and components can get ruined by rainwater, but you get the point. It’s all about prevention, which leads us to: 

Keeping Your Motorcycle Indoors

Pretty simple, but the best way to protect your motorcycle from rain is by keeping it indoors, either in a garage or shed. However, don’t forget about humidity. Avoid keeping your motorcycle inside any structure that’s too damp inside. And whether or not you have a garage or any other storage area to keep your motorcycle in, you still want to get a motorcycle cover.

Choosing a Motorcycle Cover

The worse thing you can do is leave your motorcycle out in the rain uncovered when you’re not riding it. Even if you do have an indoor storage area, a motorcycle cover protects your bike from more than just rain. It also protects it from other elements like wind, snow and sunlight, as well as bugs, dirt, pollen and other contaminants. 

While you might be tempted to cover your motorcycle with a blanket, tarp or any type of plastic, these covers aren’t designed to protect a motorcycle, especially not against rain. 

Get a cover specifically designed to shield a motorcycle from any and all types of contaminants, even when it’s kept indoors. Choose a high-quality cover made of breathable, waterproof materials to protect your bike against humidity. Before buying a motorcycle cover, make sure it’s manufactured to fit your motorcycle type. Read product reviews too, as there are cheaply made motorcycle covers out there that don’t provide adequate protection against rain.

The right cover will provide a snug fit for your bike. Otherwise, wind can blow up into the cover and create a sail effect that can knock your motorcycle over. One last thing, don’t cover your motorcycle while it’s wet, as doing so traps in moisture and creates mold and rust problems. Also, remove the cover after it’s been rained on and let it dry before reusing it.