GRIFEMA GAK1203-12
GRIFEMA GAK1203-12 Anti-Theft Bicycle Lock User Manual
Model: GAK1203-12 | Brand: GRIFEMA
Introduction
This manual provides comprehensive instructions for the safe and effective use of your GRIFEMA GAK1203-12 Anti-Theft Bicycle Lock. Please read this manual thoroughly before initial use and retain it for future reference. This 5-digit combination cable lock is designed to provide security for bicycles, motorcycles, scooters, and other personal belongings.
The GRIFEMA GAK1203-12 features a 12mm high-quality steel wire core with a PVC coated outer material for durability and corrosion resistance. Its 5-digit combination offers 100,000 permutations for enhanced security.
Safety Information
Always ensure the lock is properly engaged and secured before leaving your property unattended. While this lock provides significant security, no lock is entirely impervious to determined theft. For maximum security, consider using multiple locking mechanisms and securing your item to an immovable object.
- Do not attempt to force the lock open if the combination is incorrect.
- Keep the combination private and do not share it with unauthorized individuals.
- Regularly check the lock for any signs of damage or wear.
- Keep out of reach of small children.
Product Overview
The GRIFEMA GAK1203-12 lock consists of a durable steel cable, a robust combination locking mechanism, and a mounting bracket for convenient transport.

Figure 1: GRIFEMA GAK1203-12 Anti-Theft Bicycle Lock, showing the coiled cable and the 5-digit combination mechanism.

Figure 2: Detailed view of the lock's components, including the ABS lock shell, zinc alloy lock cylinder, strong steel cable, and zinc alloy lock head, highlighting their robust construction.
Key Features:
- High Quality Construction: 12mm high-quality steel wire with PVC coating for corrosion resistance.
- Enhanced Security: 5-digit combination with 100,000 possible permutations.
- Portable Design: Includes a mounting bracket for easy attachment to bicycles.
- Versatile Application: Suitable for bicycles, motorcycles, scooters, strollers, gates, toolboxes, and grills.
Specifications
| Feature | Detail |
|---|---|
| Brand | GRIFEMA |
| Model Name | GAK1203-12 |
| Lock Type | Combination Lock |
| Material | Alloy Steel (inner), PVC (outer coating) |
| Cable Diameter | 12mm |
| Total Length | 120 cm (47.24 inches) |
| Item Weight | 1.01 pounds (approx. 458g) |
| Combination Digits | 5 Digits |
| Color | Black/White |
| Special Feature | Portable, with mounting bracket |

Figure 3: Visual representation of the lock's total length (120cm / 47 inches) and weight (388g, which is approximately 0.85 pounds, slightly different from 1.01 pounds in specs, but the image is illustrative).
Setup
Setting Your Personal Combination:
The factory default combination for your GRIFEMA GAK1203-12 lock is 00000. Follow these steps to set your own unique 5-digit combination:
- Open the Lock: Align the default combination (00000) with the indicator marks and pull the cable head out to open the lock.
- Rotate the Knob: Locate the reset knob on the side of the lock mechanism. Rotate this knob 90 degrees clockwise (as indicated by the arrow or diagram) to the reset position. Ensure it clicks into place.
- Set New Combination: With the knob in the reset position, rotate the number dials to your desired 5-digit combination. Make sure each number is precisely aligned with the indicator marks.
- Return the Knob: Rotate the reset knob 90 degrees counter-clockwise back to its original position. This will lock in your new combination.
- Test the Combination: Scramble the numbers and then re-enter your new combination to ensure it opens correctly. This confirms your new combination is set.

Figure 4: Step-by-step visual guide on how to set your personal 5-digit combination for the lock, including rotating the reset knob and aligning the numbers.
Attaching the Mounting Bracket:
The included mounting bracket allows for convenient transport of your lock on your bicycle.
- Select Location: Choose a suitable location on your bicycle frame, such as the seat post, that has a diameter between 1 inch and 1.3 inches.
- Secure Bracket: Use the provided screws or mechanism to securely attach the bracket to the frame. Ensure it is tight and does not wobble.
- Insert Lock: Slide the lock into the bracket until it clicks into place. The lock can be easily removed by pressing the release button on the bracket.

Figure 5: Illustration of the convenient carry hook (mounting bracket) and how the lock attaches to a bicycle seat post, suitable for diameters from 1" to 1.3".
Operating Instructions
Locking Your Item:
- Align Combination: Rotate the number dials to your personal 5-digit combination.
- Open Lock: Pull the cable head out from the lock body.
- Wrap Cable: Pass the cable through the wheels and frame of your bicycle (or handles of your scooter/motorcycle) and around a secure, immovable object (e.g., a bike rack, lamppost, fence).
- Insert Cable Head: Insert the cable head back into the lock body until it clicks securely into place.
- Scramble Numbers: Scramble the numbers on the dials to secure the lock. This prevents unauthorized access.
Unlocking Your Item:
- Enter Combination: Rotate the number dials to your personal 5-digit combination, ensuring each number aligns precisely with the indicator marks.
- Open Lock: Pull the cable head out from the lock body. The lock is now open.
- Remove Cable: Detach the cable from your item and the secured object.

Figure 6: Examples of wide application for the GRIFEMA GAK1203-12 lock, including securing bicycles, motorbikes, BBQ grills, and gates.
Maintenance
Proper maintenance will extend the life and functionality of your GRIFEMA GAK1203-12 lock.
- Cleaning: Wipe the lock body and cable with a damp cloth to remove dirt and grime. Avoid harsh chemicals or abrasive cleaners.
- Lubrication: Periodically apply a small amount of silicone-based lubricant to the combination dials and the locking mechanism to ensure smooth operation. Do not use oil-based lubricants as they can attract dirt.
- Storage: When not in use, store the lock in a clean, dry place away from extreme temperatures and direct sunlight.
- Inspection: Regularly inspect the cable for fraying or cuts, and the lock body for cracks or damage. If significant damage is observed, replace the lock.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Lock will not open with correct combination. | Numbers not perfectly aligned; internal mechanism stuck; combination changed accidentally. | Ensure numbers are precisely aligned with the indicator marks. Try wiggling the dials slightly. If you recently changed the combination, try the old one or re-attempt the setting procedure carefully. |
| Dials are stiff or hard to turn. | Dirt or grime accumulation; lack of lubrication. | Clean the dials with a damp cloth. Apply a small amount of silicone-based lubricant to the dials and rotate them to distribute it. |
| Cable head does not insert or remove smoothly. | Debris in the locking mechanism; misalignment. | Check for any obstructions in the opening. Ensure the combination is correctly set before attempting to insert/remove. Apply lubricant if necessary. |
| Mounting bracket does not hold lock securely. | Bracket not tightened sufficiently; incorrect frame diameter. | Ensure the bracket is tightly secured to the frame. Verify your frame's diameter is within the supported range (1" to 1.3"). |
Warranty and Support
GRIFEMA products are manufactured to high-quality standards. For information regarding warranty coverage, please refer to the warranty card included with your purchase or visit the official GRIFEMA website. Please retain your proof of purchase for any warranty claims.
For technical support, troubleshooting assistance beyond this manual, or spare parts inquiries, please contact GRIFEMA customer service through their official website or the contact information provided with your product packaging.
Note: Product specifications and features are subject to change without prior notice.
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