Stops the wheel turning, and nothing else
A disc lock passes a pin through a brake disc so the wheel cannot turn. It is the lightest security that does anything at all, and what it does is precise and limited: it prevents the machine being ridden away, and it does nothing whatever to prevent it being lifted into a van. Saying that plainly is more useful than any figure, because a disc lock is often bought as though it were a chain. Within that limit, the things that separate one from another are readable. Certification first: insurers’ organisations publish ratings, and a lock carrying one has been attacked with named tools for a named duration. A lock with no published rating has been tested by nobody, whatever its shackle looks like. Then pin diameter, published in millimetres, and the matching question of whether the pin fits the holes in your disc — disc hole diameters vary and a 10 mm pin does not go through an 8 mm hole. Alarm versions add a movement sensor and a siren, which is the feature that turns a disc lock from a deterrent into something that attracts attention; they need a battery and they false-trigger in wind. A reminder cable from the lock to the handlebar costs almost nothing and prevents the single most common expensive mistake in motorcycling. And size, because a lock that does not fit under the seat is a lock left at home — though the figure that would settle it, what the thing weighs, is one no maker on this page publishes. We compare published certification, pin diameter, disc clearance, alarm provision, reminder cable and carrying provision.
5 mm pin · hardened steel · ABUS security level 4 · the maker states it is for low theft risk
A compact disc lock with a 5 mm hardened steel pin at ABUS security level 4, which the maker states is intended for scooters at low theft risk.
Best for: A scooter parked where the maker says this lock belongs: somewhere theft risk is low.
≈ £12 / €13
110 dB vibration alarm · aluminium alloy body · under 7 mm discs · 1.2 m reminder cable
A disc lock with a vibration-triggered 110 dB alarm in a high-strength aluminium alloy body, for discs with holes under 7 mm, supplied with a 1.2 m reminder cord.
Best for: A second lock, or a light one carried on a commute where the alarm does most of the work.
≈ €20
110 dB alarm · 7 mm hardened steel bolt · 1.5 m reminder cable · motion sensor
A disc lock with a 110 dB alarm on a motion sensor, a solid 7 mm hardened steel bolt stated resistant to cutting, drilling and rust, and a 1.5 m reminder cable.
Best for: Daily parking where the alarm and the visible lock together are the deterrent.
≈ €17
110 dB alarm · rechargeable by USB-C · ø7 mm pin · reminder cable · 3-second arming
A disc lock with a 110 dB alarm on a rechargeable battery charged by USB-C, a ø7 mm pin, keyless push-cylinder locking and a three-second arming delay.
Best for: A rider who wants an alarm and does not want to hunt for a coin cell twice a year.
≈ €30
Sold Secure Diamond · 16 mm manganese steel shackle · multi-disc cylinder · 180 cm cable
A disc lock certified Sold Secure Diamond with a 16 mm manganese special steel shackle and a multi-disc cylinder, supplied with a 180 cm loop cable.
Best for: A machine worth more than the lock, parked where it is left unattended and insured.
≈ £49 / €48
Only the specifications at least four models out of five state. A column that is more empty than full compares nothing.
| Model | Price | Amazon reference | Alarm |
|---|---|---|---|
| ABUS Element 303 | 12 £ | B08RK5JDBF (one reference across 6 Amazon marketplaces) | — |
| Anykuu 3650 | 17 £ | B093P3F8PS (one reference across 5 Amazon marketplaces) | 110 dB on a sensitive motion sensor, reacting to slight vibration (maker’s bullet) |
| Vemfay Alarm disc lock | 20 £ | B0GZVGFF7M (one reference across 5 Amazon marketplaces) | 110 dB, triggered by a high-sensitivity vibration sensor on abnormal movement or touch (maker’s bullet) |
| KRASER KR7Y | 30 £ | B0BWF2YWZN (one reference across 6 Amazon marketplaces) | 110 dB (from the title) |
| KOHLBURG KB-BS-006 | 49 £ | B08NTTC29G (one reference across 5 Amazon marketplaces) | Not published — this lock has no alarm. |
Specifications: manufacturer sheets and Amazon product pages. Prices and availability: Keepa. No product on this site has been physically tested.
Most recent revision in this category: September 18, 2026.
Nothing written into the text below is a current price. Where an amount appears in a sentence, it is the reading taken on the day that sentence was written; what a shop is asking at this moment loads beside the product itself, and that is the figure to go by.
