NG 9621239 Brake Disc User Manual

1. Product Overview

This manual provides essential information for the installation, maintenance, and safe operation of the NG 9621239 Brake Disc. This high-quality brake disc is designed for specific motorcycle models to ensure optimal braking performance and safety.

Compatibility: This brake disc is compatible with the following models:

• QUANTYA [DEL] electric VRONE (11)
• QUANTYA [TRA] electric VRONE (11)
• Riju [TRA] RS3 NKD 125 (14)

Figure 1: NG 9621239 Brake Disc. This image displays the brake disc with its distinctive design and the NG Brake Disc logo. Key dimensions (Ø218xØ62x3,5) are visible on the green header.

2. Safety Information

Brake system components are critical for vehicle safety. Improper installation or maintenance can lead to serious injury or death. Always adhere to the following safety guidelines:

• Professional Installation Recommended: It is highly recommended that brake disc installation and any related brake system work be performed by a qualified and certified motorcycle mechanic.
• Use Correct Tools: Always use the appropriate tools and follow manufacturer-specified torque settings for all fasteners.
• Cleanliness is Key: Ensure all components, especially the hub and caliper, are thoroughly clean and free of grease, oil, or debris before installation.
• New Brake Pads: Always install new brake pads when replacing brake discs. Never reuse old, worn, or contaminated brake pads with a new disc.
• Brake Fluid: If the brake system is opened, ensure proper brake fluid is used and the system is bled correctly to remove all air.
• Post-Installation Check: After installation, perform a thorough inspection of the entire brake system to ensure proper function before riding.

3. Installation Guide

This section provides a general overview of the brake disc installation process. For detailed, model-specific instructions, always refer to your motorcycle's service manual and consult a professional mechanic.

3.1. Pre-Installation Checks

• Verify that the new brake disc matches the specifications and type required for your motorcycle model.
• Ensure you have new brake pads compatible with your caliper and the new disc.
• Gather all necessary tools, including torque wrenches, sockets, and brake cleaner.

3.2. General Installation Steps

1. Secure the motorcycle on a stable stand.
2. Remove the wheel from the motorcycle.
3. Carefully remove the brake caliper from its mounting bracket. Do not let it hang by the brake hose.
4. Remove the old brake disc by unbolting its mounting fasteners from the wheel hub.
5. Thoroughly clean the wheel hub's mounting surface to remove any rust, dirt, or old threadlocker residue.
6. Install the new NG 9621239 Brake Disc onto the wheel hub, ensuring it is correctly aligned. Apply threadlocker to the disc mounting bolts as specified by your motorcycle's service manual.
7. Tighten the disc mounting bolts to the manufacturer's specified torque using a torque wrench, following a cross-pattern sequence.
8. Install the new brake pads into the caliper.
9. Reinstall the brake caliper onto its mounting bracket and tighten its bolts to the specified torque.
10. Reinstall the wheel onto the motorcycle, ensuring axle nuts are torqued correctly.
11. Pump the brake lever/pedal several times until firm pressure is felt. Check for any fluid leaks.
12. Perform a final visual inspection of all components.

Figure 2: Brake Disc Types Diagram. This diagram illustrates various brake disc designs, including standard and floating types, with and without ventilation, and wavy designs. While the NG 9621239 is a specific type, this image helps understand the diversity in brake disc construction.

4. Operation and Break-in

After installing new brake discs and pads, a proper break-in (bedding-in) procedure is crucial for optimal performance and longevity. This process allows the brake pads to conform to the disc surface.

• Initial Rides: For the first 100-200 kilometers (60-120 miles), avoid hard braking or prolonged, continuous braking.
• Gradual Stops: Perform a series of moderate stops from varying speeds (e.g., 50 km/h to 10 km/h) without coming to a complete stop. Allow the brakes to cool between stops.
• Avoid Overheating: Do not overheat the brakes during the break-in period, as this can glaze the pads and disc, reducing performance.
• Increased Performance: Braking performance will gradually improve as the pads and disc bed-in.

5. Maintenance

Regular inspection and maintenance of your brake disc are essential for safety and performance.

• Visual Inspection: Periodically inspect the brake disc for signs of wear, cracks, grooves, discoloration (indicating overheating), or damage.
• Thickness Check: Measure the disc thickness with a micrometer. Replace the disc if it falls below the manufacturer's specified minimum thickness (wear limit).
• Cleaning: Clean the brake disc surface with a dedicated brake cleaner to remove brake dust, dirt, and contaminants. Avoid using oil-based cleaners or lubricants.
• Pad Wear: Always check the brake pad wear simultaneously with disc inspection. Replace pads before they reach their wear limit.
• Fastener Torque: Periodically check the torque of the disc mounting bolts and caliper mounting bolts.

6. Troubleshooting

If you experience issues with your brake system, consider the following common problems and potential causes. Always consult a qualified mechanic for diagnosis and repair.

• Brake Noise (Squealing/Grinding):
  • Possible Causes: New pads/disc not bedded-in, contaminated pads/disc, worn pads, improper installation, loose caliper.
• Brake Vibration/Pulsation:
  • Possible Causes: Warped brake disc (due to overheating or improper torque), uneven pad wear, loose wheel bearings, suspension issues.
• Reduced Braking Performance:
  • Possible Causes: Worn pads/disc, contaminated braking surfaces, air in brake lines, low brake fluid, faulty caliper.
• Excessive Brake Dust:
  • Possible Causes: Normal wear of brake pads, especially during break-in or with certain pad compounds.

7. Specifications

Technical specifications for the NG 9621239 Brake Disc:

8. Warranty and Support

For information regarding warranty coverage, claims, or technical support for your NG 9621239 Brake Disc, please refer to the original purchase documentation or contact the retailer or manufacturer directly. Keep your proof of purchase for any warranty-related inquiries.

• Manufacturer: NG
• Contact: Refer to NG's official website or your product packaging for the most current contact information.