Can Bike Racks Get Wet (Solved and Explained!)

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Can Bike Racks Get Wet

Taking your bike rack off your car every time you aren’t using it is a real PAIN.

But every time it rains you face big problem:

Can bike racks get wet and not get damaged?

Bike racks can get wet without getting mess up but over time they will get rusty.

In this guide you’ll also learn:

  • If bike racks are actually waterproof like they claim to be.
  • How long your bike rack can be out in the rain.
  • And much more!
What's In This Guide?

      Are bike racks waterproof?

      Bike racks are waterproof BUT only to a certain extent…

      Bike racks are made from metals. These metals are strong because they have a high “cohesive force”. If you recall your high school science class, “cohesive force” is the force between two metal molecules. 

      Read More: Can My Bike Rack Go Through Carwashes

      On the other hand, water has an “adhesive force”. This is the name of the force between two water particles. 

      When water hits a bike rack, there’s a battle between the cohesive force (of metal) and the adhesive force (of water)

      For a while, the cohesive force easily outpowers the adhesive force. This is why your bike rack is waterproof in the short run.

      However, after a while, things can get NASTY… 

      The problem with wet bike racks

      You don’t have to worry about any problems if you’re driving and it raining on your bike rack.

      But DON’T let this give you false confidence.

      If you permanently leave your bike rack outside in a rainy climate (what a sin!), you will see signs of rust in just 4 days. You will also notice the vibrant paint on your bike rack slowly fading away…

      This is because, in the long run, the adhesive force can easily overpower the cohesive force.

      After a few months in rainy conditions, the bike rack will be colorless and COVERED with rust.

      However, the rusting process of a bike rack does depend on where you live. If your bike is outside in the warm desert, it can take MONTHS before any signs of rust.

      What Type Of Bike Racks Can Get Wet

      The process of rusting on your bike rack also depends on the TYPE of material it is made out of.

      In general, a bike rack is made out of one of the following five materials:

      •  Aluminum Alloy Bike Rack: If this alloy is constantly exposed to heavy rain, it will take a FEW DAYS to rust. Bike racks made out of aluminum are often heavier and less stylish than normal.
      • Titanium Bike Rack: The benefit of using titanium as a bike rack is that they are modern, lightweight and stylish. Unfortunately, if there is heavy rain, the bike rack will rust in ONE day.
      • Mild Steel Bike Rack: Mild steel is a very old school material. If your bike rack is made out of this, I suggest you get a new bike. This material is not waterproof and can rust or stain EXTREMELY EASILY.
      • Hardened Steel Bike Rack: This type of steel is often used in mountain bikes. Obviously, that means they are very waterproof. In fact, they can last up to a FULL WEEK in climates of heavy constant rain.
      • Low Density Polyethylene (LDPE) Bike Rack: Using LDPE on a bike rack makes it look cheap. But this material is impact resistant and decently waterproof. It has a similar level of rust resistance as the aluminum alloy.
      • Stainless Steel Bike Racks: People have mixed opinions on the looks of bike racks made out of Stainless Steel. But this steel contains a huge amount of chromium. Once again, high school science has taught us that chromium can act as an oxide barrier preventing rust. Therefore, this material is VERY good against heavy rain.

      Should You Cover Your Bike Rack

      Do you cover your bike rack when it SUDDENLY starts raining while biking down a street? 


      The truth is that bike racks can handle the occasional rain. However, are you planning on keeping the bike rack outside for longer than a week? Then, PLEASE cover your bike. Regardless of what material it is made of. 

      If your bike is mounted on top of the car and you are expecting rain, cover your bike up. 

      Huh, why is that?

      If you are driving on the highway with a mounted bike during heavy rain…

      You will be going at 75 mph (120km/h), and the headwind adds another 15 mph (25km/h). So, your bike will get SLAPPED with 90 mph (145km/h) of water. 

      This is enough to cause signs of rust in just a few hours!

      How do I keep my bike rack from rusting? 6 easy ways

      There are six PROVEN ways to prevent rust. Below they are:

      • Cover your bike rack up with a tarp. A tarp prevents rain and humidity from entering and rusting your bike. The only problem is that traps can ruin the beautiful appearance of your bike with their dull colors. 
      • Applying metal oil to the bike rack is another option. The beauty of metal oil is that it creates a special layer that stops rust. My only complaint is that oiling must be done regularly and can make the bike rack slippery.
      • Applying dry coating spray is pretty much “metal oil version 2.0”. The only difference is that your bike rack will not have any oil residue. 
      • Painting the metal prevents moisture from reaching the bike rack and causing rust. If you use paint, make sure it is oil-based paint (not water-soluble paint). The problem with paint is that it does not completely prevent rust. 
      • Galvanizing is the act of applying zinc onto your bike rack. This is very efficient as zinc rusts 30 times slower than all other materials. 
      • Bluing is putting on a new layer similar to rust (what?!) but much less damaging. It is made of magnetite and applied at high temperatures. Bluing creates a dark blue color (like the name) and prevents the rack from eroding for a long time. The only downside is that it is expensive.

      Not sure which method to choose?

      Just close your eyes and put your finger over a random one. They all work (to an extent). 

      Putting it all together

      Bike racks are waterproof in the short run. However, if you expose it to constant water and humidity, it will start rusting QUICKLY.  

      To figure out how long your bike rack can stay out in heavy rain (preferably never), just look at the material it was made out of. Most racks are made out of 5 standard materials. 

      If you still want extra protection, try one of the anti-rusting methods we proposed. In such a way, if you accidentally leave your bike outside for a week, it MIGHT not have any rust. 

      Photo of author
      Bryan Ray is the Co-Founder of The Biking Apex. He's a cyclist and a trainer who loves fitness and loves to teach people how to ride and maintain their bikes and bike accessories.

      The Biking Apex

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