Most chain lock listings tell you the same three things: heavy duty, anti-theft, waterproof. None of them tell you what actually matters, which is how thick the links are, how long the chain runs, and whether the sleeve will still be intact after a winter of locking to wet racks. Those three details decide whether a lock is worth carrying or just dead weight in your bag.
I went through the Best Bike Chain Locks For Motorcycle And Bicycle and compared stated chain thickness, overall length, sleeve material, and key count across every option. No field testing, just a close read of what each listing actually promises versus what it leaves vague. My overall pick for best bike chain locks for motorcycle and bicycle is the GRIFEMA Keyed Bike Chain Lock, which pairs a 4ft run of hardened steel with a sliding keyhole cover that keeps grit out of the mechanism over repeated daily use.
My top picks are just below.
Our Top Picks
| Product | RW Score | ||
|---|---|---|---|
| Best Overall GRIFEMA Keyed Bike Chain Lock with 4ft Hardened | 9.6 | Check Price on Amazon | |
| Best for Quick Errands Titanker Heavy Duty Bike Chain Lock with 6mm Links | 9.6 | Check Price on Amazon | |
| Best for Urban Commuters Kryptonite Keeper 712 Chain Lock with 7mm Hardened | 9.6 | Check Price on Amazon | |
| Best for Short Errands Weogine Bike Chain Lock with 2.72 ft Security | 9.5 | Check Price on Amazon | |
Full Reviews
GRIFEMA Keyed Bike Chain Lock uses a 7mm hardened alloy steel chain in a 4ft length with a nylon protective sleeve.
Key Facts
- Weight
- 1.7526749829 pounds
- Chain Length
- 4ft (47.24 inches)
- Chain Thickness
- 7mm
- Material
- Hardened alloy steel
Pros
- +Hardened 7mm alloy steel chain resists cutting and sawing
- +Nylon sleeve protects bike frame paint from scratches
- +4ft length locks multiple bikes or fixed objects
- +Sliding cover shields lock from rain and dust
Cons
- −Weighs 1.75 pounds, heavy for minimalist bikepacking
- −No security rating or waterproof certification stated
- −Keyed mechanism requires carrying two dedicated keys
Detailed Review
The GRIFEMA Keyed Bike Chain Lock centers on a 7mm hardened alloy steel chain, a thickness that adds real cut resistance compared to thinner cable locks. At 4ft long, it can wrap around racks, poles, or gates, and the nylon sleeve is a practical touch for keeping the chain from scuffing frame paint.
I see this working best for commuters and students who leave a bike locked outdoors and want a keyed lock with a sliding cover to keep rain and dust out of the mechanism. The snap-shut design means no key needed to lock, only to open.
The main trade-off is weight. At 1.75 pounds, it is heavier than a cable lock of similar length, which matters if you are counting grams on a bikepacking rig. No security rating is stated, so I would treat it as a deterrent for low-risk stops rather than a high-security solution.
The Titanker Heavy Duty Bike Chain Lock is a 3-foot, 6mm steel chain with two keys and a protective cloth sleeve, weighing 1.4 pounds.
Key Facts
- Weight
- 1.4 pounds
- Length
- 3 feet
- Chain Thickness
- 6mm
- Material
- Heavy-duty steel
Pros
- +6mm steel links provide basic cut resistance
- +Protective cloth sleeve limits scratches and rust
- +Two keys included for convenience and backup
- +3-foot length reaches around most bike racks
Cons
- −1.4-pound weight adds noticeable bulk to a jersey pocket
- −No security rating or anti-pick certification stated
- −Not intended for long periods in high-crime areas
Detailed Review
The Titanker Heavy Duty Bike Chain Lock uses 6mm steel links in a 3-foot chain, which is a size I'd consider for short stops rather than all-day parking. The protective cloth sleeve is a practical touch because it keeps the chain from scratching a painted frame or rusting when the lock sits in a damp pannier.
At 1.4 pounds, this chain is heavier than a compact cable lock, so I see it working best for errands where the lock lives in a backpack or basket. The included dust cover over the keyhole is a small detail that matters if the lock stays mounted on a bike rack in the rain.
Worth knowing before you buy, the listing gives no security rating or anti-theft certification, and it openly advises against leaving a bike locked outside for long periods in high-crime areas. I rate this a reasonable pick for low-risk, quick-stop situations, not as a primary lock for a loaded touring bike left unattended.
The Kryptonite Keeper 712 is a 120cm chain lock with 7mm hardened manganese steel links, a 5/10 security rating, and two keys.
Key Facts
- Weight
- 3.75 lbs (1.70 kg)
- Length
- 120 cm (4 ft)
- Material
- Hardened manganese steel
- Security Rating
- 5/10
Pros
- +Hardened manganese steel links add cut resistance
- +120cm length allows flexible locking around poles
- +Nylon sleeve shields frame paint from scratches
- +Two keys and Key Safe Program add convenience
Cons
- −3.75 lb weight is heavy for bikepacking
- −No specific waterproof or weather rating stated
- −Bulkier than a comparable U-lock
Detailed Review
The Kryptonite Keeper 712 uses 7mm four-sided chain links made from hardened manganese steel, which is the detail that separates it from a basic cable lock. At 120cm long, the chain gives enough reach to loop around a rack or pole and still catch both the frame and a wheel. The nylon sleeve is a practical touch for commuters, since it keeps the chain from scratching paint and blocks some dirt and moisture.
I rate this a reasonable pick for urban and suburban locking where you need flexibility rather than maximum security. The 5/10 security rating tells you it is not a high-security option for leaving a bike overnight in a risky area. The main trade-off is weight, and at roughly 3.75 lbs it is a real load on a bikepacking rig. I would not want to carry it on a multi-day off-road trip unless theft risk at resupply stops justified the bulk.
For a commuter or a rider locking up at a cafe, the balance of length, cut resistance, and two included keys makes sense. For a loaded tour, a lighter lock or a different security approach may suit better.
Weogine's bike chain lock pairs a 4mm alloy steel chain with a polypropylene fabric cover and three keys.
Key Facts
- Weight
- 0.77 lb
- Chain Length
- 2.72 ft
- Chain Thickness
- 4mm
- Material
- Alloy steel with polypropylene cover
Pros
- +Three keys supplied, useful when riders share one lock
- +Fabric sleeve limits paint scuffs on frame tubes
- +2.72 ft span fits multiple bikes or a fence post
- +Snap-together locking avoids fumbling with a dial
Cons
- −4mm chain is thin for high-risk urban parking
- −No stated waterproof or security certification on the listing
- −Coiled chain adds bulk to a frame bag or jersey pocket
Detailed Review
The 4mm alloy steel chain and 2.72 ft length are the two numbers that define this Weogine lock. That span is long enough to loop two or three bikes together, or thread a frame and a fixed post, which suits cafe stops and short errands rather than overnight parking in a city center.
The polypropylene fabric sleeve is the detail I keep coming back to. It separates the chain from painted frame tubes and stays cooler or warmer to the hand than bare steel, and the listing calls out resistance to rust and scratches. The snap-shut mechanism means no dial to spin, and three keys ship in the box so a partner or housemate can carry a spare.
Worth knowing before you buy, 4mm links are on the light side for serious theft risk, and the listing names no waterproof or security certification. I'd rate this a reasonable pick for low-risk stops and mixed bike-and-gate duty, not for leaving a loaded rig unattended.
Why You Should Trust Me
I do not ride with every lock I write about. What I do is read the listings closely, compare the stated chain thickness, length, sleeve construction, and key count across brands, and flag where a spec is missing or vague. That is the whole method. The RW Score on this site is a research-based rating built from those listing details and any verified ratings the retailer discloses, not a lab test and not a sponsored verdict.
Treat this as a starting point for your own shortlist. Lock requirements change with where you park, how long you leave the bike, and what your local crime pattern looks like. Check current conditions and use your own judgment before you commit to any single lock for a high-risk spot.
Final Thoughts
The two things that separate a chain lock you will actually use from one that sits in a drawer are link thickness and chain length. Thicker links resist cutting tools longer, and a longer chain lets you reach a proper fixed object instead of looping around your own frame. Everything else, sleeve color, key count, packaging, is secondary.
For most riders, the GRIFEMA Keyed Bike Chain Lock is the best overall choice. The 4ft length gives you real flexibility for locking to racks and poles, and the sliding cover over the keyhole is a small detail that matters if you ride in wet weather and do not want to fight a stiff mechanism in the rain. If budget is the deciding factor, the Bike Chain Lock, Heavy Duty Anti-Theft Bicycle is the value pick. It runs shorter and thinner than the GRIFEMA, so it suits quick errands and low-risk parking rather than overnight street storage, but it ships with three keys and a soft cloth sleeve that protects your frame from scratches.
Pick the chain that matches where you actually leave your bike, not the one with the longest feature list. That single decision removes most of the confusion in this category.
FAQs
How thick should a bike chain lock be?
For everyday commuting, a chain in the 6mm to 7mm range balances cut resistance against weight you are willing to carry. Thinner 4mm links suit short stops and low-risk areas, while anything heavier gets awkward to haul on a daily ride. Match the thickness to how long and where you leave the bike.
Can you use a bicycle chain lock on a motorcycle?
A bicycle chain lock can work on a motorcycle for short stops, but the lighter links and shorter lengths limit how much you can secure. Motorcycles are heavier and harder to move, which helps, yet a determined thief with tools will still target thinner chains. For overnight parking, a purpose-built motorcycle lock is the safer bet.
Is it better to lock your bike with a chain or a U-lock?
Chains win on flexibility because the length lets you reach racks, poles, and fences that a rigid U-lock cannot. U-locks are generally harder to cut through in a confined space. Many riders carry both, using the U-lock on the frame and the chain to secure wheels and accessories.
Do you need a key to lock a bike chain lock?
Most chain locks on this list snap shut without the key, and you only need the key to unlock. That speeds up locking and means you are not fumbling in the rain. Keep a spare key at home in case you lose the one on your ring.