Do Bicycle Brakes Freeze?

While most people prefer to stay indoors, there are a few of us that enjoy riding their bikes during the winter months. While it can be fun, the risks associated with cycling go up drastically in the winters. Bicycle maintenance becomes even more important, and one of the first things you ought to know is- do bicycle brakes freeze?

If properly maintained, bicycle brakes, whether hydraulic or rim brakes, do not freeze during the winter. Bicycle brakes will give good performance even for the low end of temperatures during a normal winter season (-20 degrees F or -29 degrees C).

The assumption here, is that your bike is being maintained correctly for the winter. Otherwise, they are prone to failure. I will give complete details of the reasons for bike brakes freezing as well as how to un-freeze them and prevent the freezing in the first place.

However, before I get into more detail- let me first give an introduction to the types of bicycle brakes (experienced cyclists can skip onto the next sub heading if you already know this).

Types of Bicycle Brakes

There are two types of bicycle brakes- hydraulic brakes and mechanical brakes.

When you press the brakes on your bike, the cables connected to the brake levers exert a pressure on your bike’s wheel rims that makes them stop by force of friction. The cables are connected to the rims via a set of callipers (those ‘V’ shaped things that you see around your tire rim).

If you have disc brakes, the callipers are connected to the hub in the centre of the wheel.

The difference between hydraulic brakes and mechanical brakes, is simply this:

Hydraulic brakes have fluid inside the cables that connect your brake levers to the tire rims. The fluid is such that it gets compressed once you brake, which exerts the required pressure on the rims to stop. In mechanical brakes, there is no fluid in the cables. It simply is the mechanical force of the cable that causes your bicycle to brake.

So, now you understand that bicycles can have 4 types of brakes:

1. Mechanical Rim Brakes
2. Mechanical Disc Brakes
3. Hydraulic Rim Brakes
4. Hydraulic Disc Brakes

Why Do Bike Brakes Freeze

Bike Brakes mainly freeze due to three reasons:

• Road salt and moisture inhibiting the callipers
• Low temperature effects on brake fluid (for hydraulic brakes only)
• Moisture leaking into the brake cables

Let’s look at these one by one.

1. Road Salt and Moisture. Road salt laid out on the roads during winters has a funny way of sticking to the underside of vehicles, your bike’s frame, etc and corroding them. It’s truly dangerous when road salt gets stuck on your brake cables and brake pads (if you have rim brakes).

A handy tip I found online is to keep squeezing the brake lightly during your ride so that the brake remains functional throughout, and you immediately notice if it isn’t functioning the way it should.

Another great tip is to keep a piece of cloth handy with you, and use it to wipe down the brake pads and cables after every ride. In fact, you ought to do it for the entire bike, because dirt, grime, moisture can settle anywhere.

I also read plenty of anecdotal accounts where moisture from the road or snow settled on the bike and started to freeze during the ride, causing the brake pads to fail.

Which is why, carrying a cloth to wipe down your bike is seriously recommended. Feel free to stop mid-ride and do this. Better to be safe than sorry.

Oh and also, if you have rim brakes- consider getting sintered brake pads for riding in wet or winter conditions. They perform much better than other types of brake pads.

Hydraulic Brakes Freezing- need to use correct type of brake fluid- DOT or mineral oil. DOY is very cheap, but absorbs water so needs to be replaced yearly. Mineral oil is expensive but has lower maintenance. DOT also is corrosive. Mineral oil freezes at around -30 degree C and DOT at around -75 degree C.

2. Low Temperature Effects on Hydraulic Brakes. Now this isn’t technically bike brakes freezing, but somewhat in the same category, so I thought I should mention it.

Basically, as the temperatures reduce and a liquid nears it’s freezing point, it will become a bit sluggish, which is what happens in the case of hydraulic brakes as well. The fluid inside the brakes flows less freely than it does at higher temperatures, which makes you feel as if the brakes aren’t working properly.

This isn’t that big a deal, as, from a safety standpoint, hydraulic brake fluids, regardless of which type you use (mineral oil or DOT) will function quite ok during the average winter season, let’s say around -20 degree F or -29 degrees C. This is because their freezing points are quite, quite low- around -40 degree F (or -40 degree C).

3.Moisture in Brake Cables. If your brake system is not fully housed, i.e: all cables are not covered with rubber coating completely, then the chances of moisture corroding the cables are higher, especially if you’re out riding in winters. In hydraulic brakes, this is taken care of because, in order to retain the brake fluid, the braking system is fully housed.

However, even rubber coating has pores that will allow some moisture to seep in. If you have a mechanical brake system, you simply need to apply some lube and see if it keeps away the moisture, else you might have to replace the cables altogether.

If you have a hydraulic brake system then, moisture leaking in can be even more dangerous. This is because water drastically affects the performance of the brake fluid. Here, the type of hydraulic fluid being used is a big factor.

Don’t worry if all this sounds complicated. I specifically wrote the next section to give you a detailed answer on what to do if water leaks into your hydraulic brake system.

What To Do If Moisture Leaks Into Hydraulic Brakes?

Hydraulic brake fluids, if mixed with water, start giving sub-optimal braking performance. One of the biggest issues is that water has a much higher freezing point than brake fluids, and if water leaks in, then it causes the brake fluid to congeal at higher temperatures and freeze much faster.

This is why most people with hydraulic brakes suffer during winter.

The best thing to do is to change the brake fluid once a year. In fact, this is highly recommended if you intend to cycle during the winter months.

There are two types of hydraulic brake fluids- mineral oil based and DOT. Mineral oils don’t attract moisture out of the air, whereas DOT does. If you use DOT fluid, it is MANDATORY for you to change it at least once a year- more often if you live in a humid place.

Final Tips For Bicycle Winter Riding

1. Get Mechanical Disc Brakes. If you can afford to upgrade, get a new tire with a disc brake. Disc brakes have a much more powerful braking mechanism than rim brakes, and will perform much better in winter conditions. I additionally suggested you get mechanical brakes because they are quite low maintenance in winters compared to hydraulic brakes.
2. Reduce Moisture As Much As Possible. Wipe down your bike after every ride and, if possible hang it with the rear wheel facing down in your garage or anywhere indoors where it’s warm. Place a couple of rags underneath and allow any moisture to leak out.
3. Consider Converting Your Bike Into A Stationary Bike For The Winter. I know a lot of people that do this during the winter months and it allows them the fun of cycling without all the hassle.