Product Overview
The Kryptonite Kryptolok Series 2 LS Bicycle U-Lock is engineered to provide moderate security for bicycles. It is suitable for use in suburban areas and for quick stops in urban environments. This U-lock features a 13mm hardened performance steel shackle and a patented deadbolt locking mechanism for enhanced security. This manual provides essential instructions for the proper setup, operation, maintenance, and troubleshooting of your lock to ensure optimal performance and longevity.

Image: The Kryptonite Kryptolok Series 2 LS U-Lock, displayed with its retail packaging, illustrating its robust design and key features.
Package Contents
- Kryptonite Kryptolok Series 2 LS U-Lock
- Two standard keys
- One "I" key (for key registration)
- EZ Mount Transportation mount
Setup and Installation
Attaching the EZ Mount Transportation Bracket
The EZ Mount Transportation mount provides a convenient method for carrying your U-lock on your bicycle frame when not in use.

Image: A diagram illustrating the FlexFrame-U Bracket, which is part of the EZ Mount Transportation system, demonstrating how it attaches to a bicycle frame for carrying the U-lock.
- Select Location: Choose a suitable location on your bicycle frame. Ensure the mount does not interfere with pedaling, steering, or other bike components.
- Secure Bracket: Secure the bracket to the frame using the provided straps or hardware. Tighten firmly to prevent movement during riding.
- Attach Lock: To attach the U-lock to the mount, align the shackle with the bracket's retention mechanism and push firmly until it clicks into place.
- Remove Lock: To remove the U-lock from the mount, press the release tab (if present) and pull the lock away from the bracket.
Note: The mount may feel stiff or difficult to operate initially. Ensure proper alignment and apply firm pressure when attaching or detaching the lock. If the mount feels excessively tight, check for obstructions or misalignments.
Operating the U-Lock
Locking Your Bicycle

Image: The Kryptonite Kryptolok Series 2 LS U-Lock in its locked configuration, demonstrating the shackle secured to the crossbar.
- Position Bicycle: Place your bicycle next to a secure, immovable object (e.g., a bike rack, sturdy pole).
- Remove Shackle: Detach the shackle from the crossbar.
- Secure Bicycle: Pass the shackle through the bicycle frame and at least one wheel, then around the immovable object.
- Engage Lock: Reinsert the shackle ends firmly into the crossbar until the patented deadbolt locking mechanism engages. You should hear a distinct click.
- Verify Security: Gently pull on the shackle to ensure the lock is fully engaged and secure.
Unlocking Your Bicycle

Image: A close-up view of the Kryptonite U-Lock's keyhole, showcasing the disc-style cylinder designed for pick and drill resistance.
- Insert Key: Insert the key fully into the disc-style cylinder.
- Turn Key: Turn the key to disengage the deadbolt mechanism.
- Remove Shackle: Pull the shackle away from the crossbar.
- Remove Lock: Detach the lock from your bicycle and the immovable object.
- Store Key: Remove the key and store it in a safe place.
Tip: Always insert the key completely before turning. If the key feels sticky or difficult to turn, refer to the Maintenance section for guidance.
Maintenance
Regular maintenance is crucial for ensuring the smooth operation and extending the lifespan of your Kryptonite U-lock.
- Lubrication: Periodically apply a small amount of lubricant (e.g., graphite-based or silicone spray) into the keyway and the locking mechanism. This practice is particularly important in dusty, wet, or cold environments to prevent seizing and ensure smooth key operation.
- Cleaning: Keep the lock clean from accumulated dirt and debris. Wipe down the shackle and crossbar with a damp cloth. Avoid using harsh chemicals, which could potentially damage the protective vinyl coating.
- Key Care: Do not force the key if it feels stuck. Ensure it is fully inserted and try wiggling it gently. If issues persist, lubricate the mechanism as described above.
Troubleshooting
Key is difficult to insert or turn
- Ensure the key is fully inserted into the keyway.
- Apply lubricant to the keyway and turn the key gently.
- Check for any debris obstructing the keyway and carefully remove it if present.
Shackle is stuck or difficult to remove/insert
- Verify that the key is fully turned to the unlock position.
- Wiggle the shackle gently while pulling or pushing. Sometimes tension on the lock can make it difficult to open.
- Lubricate the shackle ends and the internal locking mechanism within the crossbar.
EZ Mount bracket is difficult to use
- Verify that the lock is correctly aligned with the bracket's retention points.
- Apply firm, even pressure when attaching or detaching the lock.
- Inspect the bracket and lock for any signs of damage or wear that might impede smooth operation.
Specifications
- Model: LK4103
- Shackle Material: 13mm Hardened Performance Steel
- Lock Type: Patented Deadbolt locking mechanism
- Cylinder Type: Pick and drill resistant disc-style cylinder
- Internal Dimensions: 4 inches (10.2 cm) wide x 11.5 inches (29.2 cm) long
- Weight: Approximately 3.1 pounds (1.4 kg)
- Included Components: 2 standard keys, 1 "I" key, EZ Mount Transportation mount
- Security Rating: Moderate security, ideal for suburban areas and quick stops in urban areas
Warranty and Support
The Kryptonite Kryptolok Series 2 LS Bicycle U-Lock is backed by a lifetime warranty against defects in materials and workmanship.
Kryptonite also offers an Anti-Theft Protection program for registered locks. This program provides up to $1,500 in reimbursement if your bicycle is stolen due to the lock being defeated. Registration is required to participate in this program. Please refer to the official Kryptonite website for complete terms, conditions, and registration details.
For further assistance, technical support, or warranty claims, please visit the official Kryptonite website or contact their customer service department directly.
Important Safety Information
- Always secure your bicycle to an immovable object.
- For maximum security, ensure the lock passes through the bicycle frame and at least one wheel.
- Avoid leaving your bicycle unattended for extended periods, especially in high-risk areas, even when secured with a lock.
- Regularly inspect your lock for any signs of wear, damage, or malfunction. Do not use a damaged lock.





