Heavy Duty U-Lock with Cable – 21mm Alloy Steel Anti-Theft Bike Lock, Portable with Mounting Bracket

Ultimate Security for Your Ride: 21mm Alloy Steel U-Lock with 4ft Cable

Protect your bicycle, scooter, or motorcycle with industrial‑grade anti‑theft protection. This heavy‑duty U‑lock combines a 21.4mm alloy steel shackle, double‑locking mechanism, and a 3.94‑ft reinforced cable to deliver 12‑ton cutting resistance — giving you peace of mind every time you park.

Product Overview – Built to Defeat Theft

We know your bike is more than just a way to get around — it’s an investment. That’s why this U‑lock is engineered from the ground up to stop even the most determined thief. Featuring a zinc‑alloy C‑grade lock cylinder that resists picking, drilling, and prying, and a hardened steel crossbeam that has undergone multiple quenching heat‑treatment processes, every component is designed for maximum durability. The included 3.94‑ft double‑looped steel cable lets you secure your wheels and frame simultaneously, while the silicone cover protects your bike’s paint from scratches. Whether you’re commuting, running errands, or storing your bike overnight, this lock gives you the confidence to leave it unattended.

Key Features – What Makes This Lock a Cut Above

• 12‑Ton Cutting Resistance: 21.4 mm alloy steel shackle with 0.36″ silicone cover – leverage‑, cutting‑, and drill‑resistant.
• High‑Security Lock Cylinder: Zinc alloy C‑grade cylinder with complex serpentine key slots – virtually pick‑proof and rust‑resistant.
• Double‑Locking Shackle: Hardened steel crossbeam, double‑locking for superior prying resistance; multiple quenching heat treatment boosts hardness.
• 4‑Ft Reinforced Cable: 3.94 ft double‑looped steel cable with PVC shell (0.39″ diameter) – secure both wheels and frame in one go.
• Portable & Easy Installation: Compact 7.87″ × 6.3″ size; includes mounting bracket for seat posts ≤1.38″ (35 mm) – no bag needed.
• Scratch‑Proof Silicone Cover: Soft silicone sleeve protects your bike’s finish and extends lock life.

Technical Specifications

Comparison – Why Our U‑Lock Beats the Alternatives

Performance & Riding Experience – Security That Moves With You

Carrying a heavy lock can ruin an otherwise perfect ride — but this U‑lock redefines convenience. Its compact dimensions (7.87″ × 6.3″) fit easily inside a backpack or pannier, and the included mounting bracket attaches to almost any round seat post (≤35 mm) in seconds. No more digging through your bag or strapping a bulky chain to your frame. The silicone cover not only prevents scratches but also dampens rattling sounds during bumpy rides. When you arrive at your destination, the double‑locking shackle and 4‑ft cable give you the flexibility to secure the frame and both wheels — or lock your bike to a fixed object while leaving the cable looped around a second wheel. The smooth‑action lock cylinder opens effortlessly with the specially designed copper keys, and the serpentine keyway makes unauthorized duplication nearly impossible. Whether you’re a daily commuter in a busy city or a weekend trail rider, this lock delivers the security you need without adding unnecessary weight or bulk.

Ideal Use Cases – Where This Lock Shines

City Commuting: Lock your bike at train stations, office bike racks, or street posts — the cable secures both wheels while the U‑lock anchors the frame. Perfect for high‑risk urban areas.

Campus / University: Students can lock their bikes for long lecture hours; the silicone cover protects paint, and the 12‑ton resistance deters thieves.

Recreational Rides: Stop at a café or park without worrying. The lightweight design (just 2.1 lbs) won’t slow you down.

Motorcycle & Scooter: Use the U‑lock on the disc brake or frame, and the cable for the helmet or rear wheel.

Why Choose This U‑Lock – Your Investment Deserves the Best

We didn’t cut corners. From the C‑grade lock cylinder to the quenching‑hardened crossbeam, every detail is engineered for maximum security. The included mounting bracket and silicone cover show we care about your convenience and your bike’s appearance. Most locks in this price range use thinner steel or simpler cylinders — our 21.4 mm alloy steel shackle and double‑locking design put you in a different tier of protection. Plus, you get three premium copper keys and a 4‑ft cable, all in one package. No hidden costs or extra accessories needed. We stand behind our product because we ride too — and we know what it takes to keep a bike safe.

Safety & Warranty – Covered So You Can Ride Worry‑Free

Your safety and satisfaction are our priorities. This lock meets or exceeds industry standards for cutting and prying resistance. The silicone cover not only prevents scratches but also provides a non‑slip grip when handling. The keys are designed to resist corrosion and breakage. We offer a limited 1‑year warranty against manufacturing defects. If you encounter any issue, our dedicated customer support team will respond within 24 hours. Remember to register your lock for extended warranty options. For maximum security, always lock your bike to a fixed, immovable object and ensure the shackle is fully engaged.

Frequently Asked Questions

Q: Will the lock fit my electric bike or fat‑tire bike?
A: The U‑lock has a 7.87″ × 6.3″ interior space, which fits most standard frames and wheels. For extra‑large frames or fat tires, you may need to use the cable as a secondary lock to secure the rear wheel.

Q: How do I use the mounting bracket?
A: The bracket attaches to any round seat post up to 1.38″ (35 mm) in diameter. Simply slide it onto the post, tighten the screw, and click the lock into place. No tools required.

Q: Can I get replacement keys?
A: Yes. Write down the key code stamped on the original keys, and you can order duplicates from our support team. We recommend keeping one spare key in a safe place.

Q: Is the lock weather‑resistant?
A: The silicone cover and zinc alloy cylinder offer good protection against rain and dust. However, for long‑term outdoor storage, we recommend occasional lubrication of the keyway to maintain smooth operation.

Secure Your Ride Today – Don’t Let Theft Ruin Your Day

Stop worrying and start riding. With 12‑ton cutting resistance, 3 keys, and a 4‑ft cable, this U‑lock is the only security solution you’ll need. Click Add to Cart now and enjoy peace of mind on every trip.