Brake components are crucial for ensuring our safety while riding a bicycle. Among them, the disc brake system has become the standard configuration for sports bicycles and is the most critical part of the entire braking system. Unfortunately, many cycling enthusiasts overlook the importance of the disc brake system and are uncertain about its function, maintenance, and how to differentiate between various sizes. In this article, we will delve into these topics and provide a detailed overview of the disc brake system for all cycling enthusiasts to understand and appreciate.
What is a disc brake used for?
In cycling, a disc brake is used as a braking system for bicycles. It is a type of brake that uses a rotor, typically made of metal, that is mounted on the wheel hub and a caliper that is mounted on the frame or fork. When the brake lever is pulled, the caliper squeezes the rotor, creating friction and slowing down or stopping the wheel.
Disc brakes are becoming increasingly popular in cycling because they offer several advantages over traditional rim brakes. They provide more consistent and reliable braking performance, particularly in wet or muddy conditions, and they require less maintenance over time. Additionally, they are typically more powerful than rim brakes, which can be important for riders who are cycling at high speeds or carrying heavy loads.
Disc brakes come in two types: hydraulic and mechanical. Hydraulic disc brakes use fluid to transmit the force from the brake lever to the caliper, while mechanical disc brakes use a cable. Both types can provide excellent stopping power, but hydraulic disc brakes are generally considered to be more powerful and offer better modulation.
Overall, disc brakes are an important component of modern bicycles, and they can significantly improve the safety and performance of riders on the road or trail.
What is the difference in size of disc brake rotors?
The disc brakes of bicycles are usually divided into sizes of 140mm, 160mm, 180mm, 203mm, and 220mm. For road bikes with hydraulic brakes, 140mm and 160mm disc brakes are the most common. Considering that mountain bikes require more braking power and the tires can provide more grip, disc brake sizes generally start at 160mm. The current mainstream trend is to use larger 180mm or even 203mm (200mm) disc brakes on the front wheel of XC(Cross Country) mountain bikes to further enhance braking power.
Generally speaking, the larger the disc, the longer the brake lever when braking, the greater the braking force and the more efficient it is. Based on current trends, larger brake discs can provide more braking force, which is not in dispute. Under other conditions remaining unchanged, simply increasing the size of the disc can obtain more braking force. This is because a larger disc can provide a longer lever arm for the brakes, or a larger brake radius.
What are the benefits of a thicker brake disc rotor?
- Increasing the size while maintaining braking power ensures better resistance to twisting forces.
- A thicker disc rotor has a greater oil capacity for heat dissipation.
- A thicker disc rotor is less likely to vibrate or generate noise due to resonance.
- It is more rigid and has a stronger ability to resist deformation.
- Pairing a more powerful caliper and brake pad with a stronger disc rotor results in a more linear and powerful braking force.
- Compared to a 1.8mm thick disc rotor, a 2.3mm thick disc rotor has an 8% improvement in heat resistance, a 47% increase in rigidity, and provides stronger braking power.
It's important to note that there are tradeoffs to using thicker brake discs, such as increased weight and potential compatibility issues with certain bike frames or components. It's always best to consult with a professional bike mechanic to determine if a thicker brake disc is right for your specific bike and riding style.
How to install the brake disc?
Installing the bike brake disc involves a few steps, and it is important to follow the manufacturer's instructions carefully to ensure proper installation. Here is a general guide to help you install a bike brake disc:
- Gather the necessary tools: You will need a torque wrench, hex wrenches, and a rotor truing tool.
- Remove the wheel from the bike: Use a hex wrench to loosen and remove the axle bolts, then slide the wheel out of the frame.
- Remove the old rotor (if applicable): If you are replacing an old rotor, use a hex wrench to remove the bolts that hold it in place.
- Install the new rotor: Slide the new rotor onto the hub, lining up the bolt holes with those on the hub. Tighten the bolts using a torque wrench, following the manufacturer's recommended torque specifications.
- Mount the wheel back on the bike: Slide the wheel back into the frame, ensuring that the axle is properly seated in the dropouts. Tighten the axle bolts using a torque wrench, following the manufacturer's recommended torque specifications.
- Adjust the brake caliper: Use the rotor truing tool to align the brake caliper so that it is centered over the rotor. Tighten the bolts that hold the caliper in place.
- Test the brake: Squeeze the brake lever to ensure that the brake engages properly and does not rub against the rotor. If the brake rubs, use the rotor truing tool to adjust the caliper until it is properly aligned.
Once you have installed the brake disc and tested it, you are ready to ride your bike again. If you are unsure about any of these steps, it is always best to consult with a professional bike mechanic for assistance.
How to maintain the brake disc?
Maintaining your bike brake disc is essential for ensuring your safety while riding. Here are some steps you can take to maintain your bike brake disc:
- Keep the brake disc clean: The brake disc should be kept clean to prevent any buildup of dirt, debris or oil. Use a clean, lint-free cloth or paper towel to wipe the brake disc before and after each ride.
- Check the brake pads: Regularly check the brake pads for wear and tear. The brake pads should be replaced if they are worn down or damaged. If the brake pads are dirty or glazed, remove them from the caliper and clean them with rubbing alcohol.
- Inspect the brake caliper: Check the brake caliper for any signs of damage, such as cracks or deformation. If the caliper is damaged, it should be replaced.
- Lubricate the moving parts: Lubricate the moving parts of the brake system, such as the brake lever, cable and caliper, to ensure smooth and efficient operation.
- Check the rotor for warping or damage: Check the rotor for any warping or damage. If the rotor is warped or damaged, it should be replaced.
- Adjust the brake pads: Adjust the brake pads to ensure that they are properly aligned with the rotor. The pads should be adjusted so that they make contact with the rotor evenly and do not rub against the rotor excessively.
By following these steps, you can maintain your bike brake disc and ensure that your bike is safe and ready for your next ride.
Please take note of the following safety guidelines:
- After riding, do not touch the brake disc with your hand as it may cause burns.
- Allow the brake disc and brake pads to run in for a period of time before applying heavy braking. Avoid installing new ones and immediately subjecting them to intense pressure.