Best Motorcycle Disc Lock Alarm: 10 Options Compared

#1 · Best Overall

1. RADIKAL RK15

• dimensions: 4.37 x 2.64 x 1.61 in
• Dimensions: 4.37 x 2.64 x 1.61 in

Best for: SRA-approved heavy-duty security.

Why it ranks #1: Its 120 dB alarm, warning pre-alarm, SRA approval, and 14 mm double-locking pin combine audible alerting with substantial listed physical security.

A 14 mm double-locking pin and SRA approval define the RADIKAL RK15 as a heavy-duty choice for riders prioritizing physical resistance. Its hardened carbon-molybdenum steel construction is paired with an optional 120 dB alarm, so owners can choose whether to arm audible deterrence.

The 14 mm double-locking pin is intended to resist force attacks, while the hardened steel body provides the physical barrier. The SRA approval reflects successful tests against saws, shears, hammers and levers. For audible security, the 120 dB alarm includes a warning pre-alarm and LED alert, with optional activation for quieter situations. Three keys are included for regular use and keeping a spare available.

Skip it if you need a smaller pin for narrow disc openings; the Kryptonite Keeper Alarm Disc Lock uses a 5.5 mm pin.

Best for riders seeking SRA-approved, attack-tested physical security with optional alarm use. Its 14 mm double-locking pin is substantial, so disc-hole compatibility is the key fit boundary.

Listed on Amazon as: RADIKAL RK15 Premium Motorcycle Disc Lock with Alarm | Optional Activation, 120 dB, LED Alert, Warning Pre-Alarm | SRA Approved Anti-Theft Brake Disc Lock, Double Locking 14 mm Hardened Steel

#2 · Best Approved Security

2. URBAN UR10

• dimensions: 3.54 x 2.56 x 1.61 in
• Material: Special hardened.steel
• Dimensions: 3.54 x 2.56 x 1.61 in

Best for: Approved high-security riders.

Why it ranks #2: This alarm lock pairs a 120 dB alarm with SRA approval, Sold Secure Gold testing, a 10 mm double-locking shaft, and a carrying pouch.

A 10 mm double-locking shaft is the URBAN UR10’s defining feature, giving riders a substantial physical barrier alongside its 120 dB alarm. SRA approval and Sold Secure Gold testing make it a security-focused choice for motorcycles where certified protection matters.

Forged, hardened steel and the 10 mm double-locking mechanism connect physical strength to resistance against force attacks; the listing says it has been tested against saws, drills, crowbars and picklocks. Its SEK PLUS DISCTECH cylinder is described as anti-drill and anti-picking. The 120 dB alarm, warning alert and LED add electronic deterrence, while the supplied carrying pouch, keys and Allen wrench make transport and setup more convenient.

Skip it if you prioritize a lighter lock for everyday pocket or bag carry; the Kryptonite Keeper Alarm Disc Lock weighs 415 g.

Best suited to riders prioritizing tested, high-security physical protection with an alarm for motorcycle parking. Account for its 920 g weight when carrying it, and ensure the 10 mm shaft suits your disc.

Listed on Amazon as: URBAN UR10 Approved Motorcycle Disc Lock with Smart Alarm | 120dB, LED, Warning, A+ Sensitivity, X2 ON | SRA & Sold Secure Gold Tested Anti-Theft for Motorbike | 10mm Double Locking, Hardened Steel

#3 · Best Warning Alert

3. URBAN UR6B

• dimensions: 3.31 x 2.36 x 1.57 in
• Dimensions: 3.31 x 2.36 x 1.57 in

Best for: Flexible alarm-mode commuters.

Why it ranks #3: Its 120 dB alarm is backed by a warning pre-alert, A+ sensitivity, LED signal, waterproof construction, and a 6 mm pin.

A pre-alert warns before the 120 dB alarm sounds, giving the URBAN UR6B a staged response to tampering rather than relying only on a loud siren. Its alarm can also be used or left off, while the 6 mm pin fits most motorcycle and bicycle brake discs.

The WARNING pre-alert and A+ sensitivity are intended to detect theft attempts before the full alarm, while the LED light signal adds a visible alert. Choose alarm or non-alarm use to suit where the bike is parked. Its 6 mm locking pin fits most motorcycle and bicycle brake discs, and the waterproof construction plus long-life CR2 battery support outdoor use without frequent battery attention. Three keys are included.

Skip it if you need a 10 mm pin for larger disc holes; the URBAN UR10 has a 10 mm double-locking shaft.

A practical pick for riders wanting a waterproof, flexible alarm lock for most motorcycle or bicycle discs. Choose another pin size if your brake disc has larger holes; the UR6B uses a 6 mm pin.

Listed on Amazon as: URBAN UR6B Hi-Tech Motorcycle Disc Lock with Smart Alarm | Best Value | 120dB, LED, Warning, A+ Sensitivity, Truly Waterproof, Long-Life CR2 Battery, Carried Locked, Bike Anti Theft Wheel Brake Locks

#4 · Best Pre-Alarm

4. RADIKAL RK9

• dimensions: 2.76 x 2.36 x 1.18 in
• Material: Metal Hardened steel
• Dimensions: 2.76 x 2.36 x 1.18 in

Best for: Waterproof warning-alarm riders.

Why it ranks #4: The hardened-steel lock offers a 120 dB alarm, warning pre-alarm, LED alert, and 100% waterproof claim in a compact format.

A warning pre-alarm precedes the RADIKAL RK9’s 120 dB siren, giving riders an early alert before a full alarm response. Its full-metal hardened-steel construction and 100% waterproof description pair physical disc locking with electronic deterrence for everyday motorcycle, e-bike or bicycle use.

The warning stage can alert nearby people to initial manipulation, while the 120 dB alarm supplies the louder follow-up response. Hardened steel forms the physical lock, and the full-metal construction supports the disc-lock role. Its compact 2.76 by 2.36 by 1.18 inch dimensions make it easier to store than a larger security device. The listing also identifies it for motorcycle, e-bike and bicycle security and describes it as fully waterproof.

Skip it if you need a stated pin diameter or a tested security approval; the URBAN UR10 lists a 10 mm shaft and SRA approval.

A match for riders who want a compact, waterproof lock with a staged 120 dB alarm across motorcycle, e-bike or bicycle use. Verify disc compatibility where a specified pin size is essential.

Listed on Amazon as: RADIKAL RK9 Disc Lock with Premum Alarm 120db ON/Off, LED Night Alert, Warning Pre-Alarm, 100% Waterproof, Full Metal Heavy Duty Brake Lock Universal Anti Theft Device for Motorcycle, E-Bike, Bicycle

#5 · Best Reminder Cable

5. KRASER WA6Y

• dimensions: 3.54 x 2.36 x 1.57 in
• Material: Metall
• Dimensions: 3.54 x 2.36 x 1.57 in

Best for: High-visibility parking deterrent.

Why it ranks #5: Its 110 dB alarm gives three warning beeps before a longer alarm, and the package includes a reminder cable, pouch, and three keys.

Bright yellow coloring makes the KRASER WA6Y easy to spot on a brake disc, providing a visible deterrent as well as an alarm. When tampering is detected, it first gives three warning beeps; continued manipulation triggers a longer, louder alarm.

The staged warning gives a nearby person an initial alert before the longer alarm sounds if manipulation continues. Reinforced construction provides the physical disc-lock barrier, while the weather-resistant description supports use in exposed parking conditions. The package lists three keys, two batteries, an Allen key and a pouch, giving riders spares and a way to keep the lock and small accessories together.

Skip it if you require a stated locking-pin diameter before buying; the Kryptonite Keeper Alarm Disc Lock specifies a 5.5 mm pin.

Suitable for riders who value a visible lock and staged audible warning for motorcycle, moped or e-bike parking. Check the disc-lock fit details carefully, since a pin diameter is not provided in the listing.

Listed on Amazon as: KRASER WA6Y Alarm Disc Lock, Reinforced Disc Brake Lock with 3 keys (others 2), Heavy Duty Anti-Theft Motorcycle Lock with Alarm,110dB, Weather-Resistant, Reminder Cable, Pouch, Motorbike Moped E-Bike

#6

6. Kryptonite Keeper

• dimensions: 1.5 x 0.79 x 1.5 in
• Material: Multi
• Dimensions: 1.5 x 0.79 x 1.5 in

Best for: Compact smaller-vent rotors.

Why it ranks #6: The compact 415 g lock has a 100 dB alarm, IPX7 waterproof electronics, and a 5.5 mm pin for rotor holes up to 7 mm thick.

A 5.5 mm locking pin fits smaller rotor vent holes, giving the Kryptonite Keeper Alarm Disc Lock a practical fit advantage for compatible motorcycle and scooter discs. Its compact, 415 g body combines that physical lock with a 100 dB tamper-triggered alarm.

The stapler-style form is described as compact and lightweight, making it easier to carry than a bulky security device. A dual-reinforced disc-style cylinder provides the physical locking point, while the 100 dB alarm activates when tampering is detected. IPX7 waterproof electronics protect the alarm module in wet conditions. The pin fits rotors up to 7 mm thick, but the hole size also needs to accommodate its 5.5 mm pin.

Skip it if you want a louder listed alarm; the RADIKAL RK9 offers a 120 dB alarm with a warning pre-alarm.

Well suited to riders seeking a compact, waterproof alarm lock for discs with smaller vent holes. Check both the 5.5 mm pin opening and the rotor thickness limit of 7 mm before choosing it.

Listed on Amazon as: Kryptonite Keeper Alarm Disc Lock, Heavy Duty Anti-Theft Motorcycle Disc Break Lock Waterproof 100db Alarm, 5.5mm Pin Powersport Disc Break Lock for Motorbikes Scooters

#7

7. YOHOOLYO LK603

Best for: Waterproof one-press alarm users.

Why it ranks #7: This 110 dB alarm lock has a 7 mm pin, waterproof construction, one-press operation, and a 5 ft reminder cable with carrying pouch.

One-press arming activates the YOHOOLYO LK603’s alarm, making its basic locking workflow straightforward when parking. The 110 dB siren and waterproof construction suit riders who want audible deterrence outdoors, and the included 5-foot reminder cable helps flag the lock before departure.

The 7 mm pin secures the brake disc, while forged stainless steel provides the listed crash-resistant construction. Pressing the button arms the alarm, and the 110 dB sound activates when movement is detected. Waterproofing supports outdoor parking, and the 5-foot reminder cable links the lock visually to the bike’s controls. A carry pouch is also included for storing the lock between rides.

Skip it if you need a 10 mm double-locking shaft and security approvals; the URBAN UR10 provides a 10 mm pin with SRA approval.

A sensible option for riders wanting a simple, waterproof alarm lock with a reminder cable for outdoor stops. Its 7 mm pin remains the key fit consideration for the motorcycle or bicycle disc.

Listed on Amazon as: YOHOOLYO Alarm Disc Lock Motorcycle Disc Brake Lock Anti-Theft Waterproof 110 dB 7mm Pin 5ft Reminder Cable for Motorcycles Bike Scooter Carry Pouch (Red)

#8

8. RUBY.Q LK-603

• Material: Alloy Steel

Best for: Cable-and-pouch alarm kit.

Why it ranks #8: The 110 dB alarm set includes a 7 mm pin lock, reminder cable, storage bag, two keys, and spare button batteries.

A 5-foot reminder cable comes in the RUBY.Q kit, helping make the disc lock more visible as a reminder before riding away. The 110 dB alarm responds to vibration or shock, while the included pouch keeps the lock and accessories together between stops.

The 7 mm pin provides the disc-lock connection, and the alarm activates when it senses vibration or shock, adding a loud warning while the bike is parked. The 5-foot reminder cable is useful for making the lock’s presence apparent at a glance. Two security keys, an Allen wrench and a storage bag round out the kit; six internal batteries and six backups are listed for continued battery supply.

Skip it if you want a waterproof specification or one-press arming; the YOHOOLYO LK603 listing explicitly describes both.

A good match for riders who want an alarm lock bundled with a long reminder cable and storage pouch. Its 7 mm pin and button-cell battery setup are important considerations for disc fit and upkeep.

Listed on Amazon as: Alarm Disc Lock, 110 dB 7mm Pin 5ft Reminder Cable with Carry Pouch

#9

9. NEIKO 52908A

Best for: Five-second motion-sensor arming.

Why it ranks #9: Its 110 dB alarm uses a five-second delayed motion sensor, and the listing describes a weather-resistant, waterproof all-metal construction.

A five-second delayed motion sensor gives the NEIKO 52908A a clear arming interval before its alarm responds to shock or movement. The 110 dB sound and all-metal construction make it a multi-vehicle disc-lock option for motorcycles, bicycles, scooters and mopeds.

Press-button operation sets the lock, while the five-second delay gives the motion sensor time to move into its armed state. Once active, shock or movement can trigger the 110 dB alarm. The listing describes the all-metal lock as rust-resistant, weather-resistant and waterproof, supporting outdoor use. Its stated compatibility covers motorcycles, bicycles, scooters and mopeds, so it serves riders with more than one vehicle type.

Skip it if you want a warning pre-alarm before a louder siren; the RADIKAL RK9 lists a warning pre-alarm and 120 dB alarm.

A practical choice for owners seeking a waterproof alarm lock across several listed vehicle types. Its button operation and five-second delay suit a routine arming step, but the alarm is not immediate.

Listed on Amazon as: NEIKO 52908A Motorcycle Locks Anti Theft with Alarm, Motorcycle Disc Lock with Alarm, Disk Lock Anti-Theft Motion Sensor, Security Lock Brake, Universal Alarm Lock for Motorcycles, Bicycles & More

#10

10. Mathtoxyz MA-CS-B

Best for: Apartment and outdoor parkers.

Why it ranks #10: This motorcycle-focused option has a 110 dB alarm and movement sensors, but the supplied details give less specific lock and fit information.

A five-second arming delay gives the Mathtoxyz lock a short pause after setup before its 110 dB alarm is activated. Shock and movement sensors then provide an audible response, making it a straightforward added deterrent for bikes parked outside or around apartment buildings.

To operate it, press the lock button and wait for the beep after five seconds, which indicates the alarm is activated. Built-in sensors detect shocks and movement, triggering the 110 dB alarm. The included 5-foot reminder cable can help flag the lock before riding away, while the supplied keys and carry pouch support routine use and storage. Its listed compatible-device category is motorcycles.

Skip it if you need a specified waterproof rating or a named compatible-device range beyond motorcycles; check those details before choosing this model.

A fit for motorcycle owners seeking a simple alarm lock for outdoor or apartment parking, with a reminder cable for departure checks. Allow for the five-second activation sequence each time you arm it.

Listed on Amazon as: Motorcycle Alarm Disc Brake Lock, Motorcycle Locks Anti-Theft Security Wheel Disc Lock Waterproof 110dB Alarm Sound with 5ft Reminder Cable Keys and Carry Pouch for Motorbike Bike Scooter