The braking system is one of the most vital parts of a motorcycle, and keeping it in top condition is a duty that all riders have to follow religiously. Beginner riders would also do well to familiarize themselves with the various components that make up the brakes.
When studying the braking system, some may wonder why the front brake fluid reservoir varies in design depending on the motorcycle. Some bikes may have smaller, partially hidden containers, while others prominently show off the setup. Does it have something to do with safety, convenience, or something else altogether?
Why front brake fluid reservoirs vary in design
Like most other parts of a bike, the brake fluid reservoir is a component specifically designed for each model. Designers and engineers put careful thought into how it's configured for a particular motorcycle.
Some models have front brake fluid reservoirs that are cylindrical and sometimes translucent in design. The reason for this is convenience. Common on larger naked bikes and sportbikes, this prominent reservoir setup makes it easier for owners to determine exact brake fluid levels without missing a beat. This setup is also better for knowing when it's time to replace the brake fluid. Access is simple as well, so the brake fluid can be drained and filled quite easily.
Other motorcycles have understated, boxy front reservoir designs that are compact and blend in better with the handlebar. These designs may have smaller openings for checking fluid levels. They are also more common on scooters and other small-displacement motorcycles.
There's no telling which configuration is better, as it's mostly a matter of personal preference. If you don't like the look of your stock reservoir, there are countless aftermarket options to choose from. Depending on the product you select, replacement reservoirs can hold more brake fluid and be more durable or visually appealing.
How motorcycle brakes work
Now that we've learned why brake fluid reservoirs differ in design, it's a good practice to look at how the braking system functions. Most bikes today are equipped with disc brakes, much like what you'll find in cars. Models with drum brakes still do exist, but they're getting harder and harder to find each year.
On motorcycles, front and rear disc brakes are the most common. These two brakes trigger separately, with the front activated by the right side lever on the handlebar and the rear through a dedicated foot pedal. There's also a second, less common configuration that triggers both brakes with a single lever.
The master cylinder assembly, which is attached to the reservoir, converts kinetic force into hydraulic pressure. When you engage the front or rear brake, the lever or cable triggers the master cylinder, which in turn tells the piston to create pressure on the brake fluid. Because fluids cannot be compressed, the resulting pressure is transferred to the brake lines and into another piston. This pressure goes to the brake caliper, and eventually, to the brake pads.
When to replace motorcycle brake fluid
Regular brake maintenance is a must for any rider. Not only does it keep you safe, but it also ensures that your bike is in the best condition it can be. The rule of thumb for when to replace your brake fluid is every two years. Ideally, it's best not to let your fluid levels get anywhere close to empty. Otherwise, you'll be replacing more than brake fluid, as low levels can indicate that your brake pads are worn and used up.
You should also check regularly for any leaks in the reservoir. Never ride with leaking brake fluid, as the results can be disastrous. Brake fluid leaks are typically due to a malfunctioning hose, a corroded master cylinder, or loose front caliper bleed caps.