Kryptonite Keeper 712 Combo Chain Lock — 4 ft Resettable 4‑Digit, 7mm Manganese Steel

The Kryptonite Keeper 712 Combo is a 4‑ft resettable chain lock with 7mm four‑sided manganese steel links and a 4‑digit combination, built for everyday urban security and quick stops.

This chain lock balances portability and protection for riders who need reliable theft resistance without the weight and bulk of heavier security systems. Constructed from 3T manganese steel, the Keeper 712 integrates a patent‑style end link for secure locking and a drilled‑resistant disc cylinder. A weather‑resistant nylon sleeve helps prevent frame damage and reduces corrosion, while the resettable 4‑digit combination removes the need to carry keys.

How much security does this lock provide for daily rides?

The Keeper 712 scores 5 out of 10 on Kryptonite’s internal scale and holds a Sold Secure Bronze rating, which means it deters opportunistic thieves and resists common attack methods for short to moderate stops. It’s designed for city quick stops, commuter use, and lower‑risk overnight parking in rural settings.

• 7mm four‑sided 3T manganese steel chain links resist bolt cutters and leverage tools.
• Hardened deadbolt mechanism increases holding power against forced entry.
• Disc‑style cylinder offers pick and drill resistance for extra lock integrity.

Is the combination easy to set and use during a busy commute?

Yes — the Keeper 712 features a smooth, positive‑indexing 4‑digit dial that you can reset to a personal code. The mechanism is straightforward for daily use, and Kryptonite’s Combo Safe Program stores your code online for recovery if you forget it.

• Over 10,000 possible combinations for secure personalization.
• Positive‑indexing dial prevents accidental re‑sets while on the go.
• Online code storage option reduces the worry of forgotten combinations.

Will this chain damage my bike’s paint or stand up to weather?

The chain ships with a durable, weather‑resistant nylon sleeve that helps protect your frame from scratches and minimizes exposure of the metal to rain and road salt. The sleeve also reduces noise from chain movement and extends the chain’s usable life when used with routine care.

• Full‑length nylon sleeve cushions contact with the frame and components.
• Weather resistance reduces surface corrosion and maintenance needs.
• Removable sleeve design lets you clean or replace it if necessary.

How portable is the Keeper 712 and what are the practical dimensions?

This lock is 120 cm (approximately 4 feet) long, offering enough reach to secure both frame and wheel to thicker posts while remaining compact enough to carry. It weighs about 3.75 pounds, a manageable tradeoff for the added security compared with lighter cable locks.

• 120 cm length fits most urban fixtures and common bike racks.
• Approximately 3.75 lb weight balances protection with carry comfort.
• Ergonomic keys come standard if you prefer using the included key backup.

Who this is for: The Kryptonite Keeper 712 Combo is aimed at city commuters, students, and recreational riders who want reliable protection for short to moderate stops without investing in heavier, more expensive high‑security chains. Choose this model if you need a portable, user‑friendly lock with resettable combination convenience and frame protection for everyday urban use.