Kryptonite Heavy Duty Motorcycle Alarm Disc Lock — 120dB Siren, Weather-Resistant Zinc Body, Fits Rotors up to 6.5mm

The Kryptonite Heavy Duty Motorcycle Alarm Disc Lock is a compact, weather-resistant disc brake lock with a 120dB motion-activated siren that deters theft and locks rotors up to 6.5mm thick.

Designed by Kryptonite, a brand with decades of security expertise, this alarm disc lock combines a hardened steel locking pin and zinc diecast housing with a motion-sensitive alarm module for audible theft deterrence. It automatically arms when locked, runs on replaceable batteries that can last up to a year, and is built to withstand rain and road grime so you can leave your bike, scooter, or e-bike with greater confidence.

How loud is the alarm and how does it activate?

The integrated siren reaches 120dB and triggers instantly when the motion sensor detects tampering or movement. This high-decibel output is designed to draw immediate attention and potentially scare off opportunistic thieves.

• 120dB motion-activated siren for strong audio deterrence
• Instant activation on movement or impact to the wheel
• Audible alarm continues until the lock is unlocked with its key

What materials and dimensions make this lock reliable?

Construction focuses on durability: a zinc diecast body protects the electronics and a 6mm hardened steel locking pin resists cutting or deformation. The lock fits disc brake rotors up to 6.5mm thick and is compact enough to carry on rides without bulk.

• Zinc diecast housing shields the unit from impacts and corrosion
• 6mm hardened steel pin resists sawing and bending
• Compatible with rotors up to 6.5mm thickness for most motorcycles and scooters

How easy is it to use and maintain on a daily basis?

Operation is straightforward: insert and turn the key to lock, and the alarm arms automatically—no extra steps required. Battery replacement is simple, and the electronics are designed for weather resistance so routine maintenance is minimal.

• Auto-arming when the key is turned to lock—no buttons to press
• Uses replaceable batteries with up to one year of typical service life
• Weather-proof electronics reduce corrosion and maintenance needs

Can I use this on other vehicles or gear besides motorcycles?

Yes. While optimized for motorcycles and scooters, the compact profile and hardened pin make it suitable for e-bikes, bicycles with compatible rotor thickness, or securing other personal gear where a disc lock fits. Consider rotor thickness and clearance before purchase.

• Works with motorcycles, scooters, e-bikes, and some bicycles
• Compact design for easy transport in a backpack or tailbag
• Versatile security for various on-the-go situations

Who is this for: Riders who want a straightforward, strong visual and audible theft deterrent—commuters, weekend riders, and urban motorcyclists who need a portable, weather-resistant disc lock with a loud alarm. If you value a lock that arms automatically, withstands the elements, and signals tampering with a 120dB siren, the Kryptonite Heavy Duty Motorcycle Alarm Disc Lock is built to add another layer of protection to your ride.