Kryptonite Keeper 712
Top PickWhat We Like
- Sold Secure Bronze rating and thick steel chain deter theft effectively.
- Nylon sleeve protects bike frame from scratches and adds weather resistance.
- Resettable 4-digit combination eliminates the need for keys.
Worth Noting
- At 4.5 lb, it adds significant weight to carry
- Combination dial may become stiff or jam after extended use in some cases.
- Length
- 4 ft
- Material
- 3T manganese steel, nylon sleeve
- Digits & Reset
- 4-digit, resettable
- Type & Thickness
- Chain, 7mm
Read the full review
The Keeper 712 earns a Sold Secure Bronze rating with its 7mm 3T manganese steel chain, a level of independent certification most budget combination locks lack. That added security comes at a cost: the chain weighs 4.5 lb, making it one of the heavier portable locks. The 4-foot length offers flexibility for securing to posts and racks, while the nylon sleeve keeps the chain from scratching your frame.
This lock is best suited for commuters with e-bikes or high-value bicycles parked in moderate-risk urban areas where theft deterrence matters more than portability. Some users have noted that the combination dial can become stiff or jam after months of use, so occasional lubrication or careful handling is worth keeping in mind. If you are willing to trade portability for independent security, the Keeper 712 fills that gap.
Secure it to a bike frame mount or carry in a bag — the weight makes pocket carry impractical.
Bottom line: For commuters locking an e-bike in moderate-risk areas, the Keeper 712 justifies its weight with real security — but it is not a lock you will enjoy carrying far.