Match the lock to the risk, not to the bike. What the security ratings actually mean, where each lock type belongs, and how to lock up so the lock matters.
Buy the Kryptonite Parkview U-lock if the bike is parked in suburbs, at a workplace, or for short stops in daylight. If it lives in a city or is left outside for hours, buy the Evolution Mini-7 instead and accept the weight.
The rule that governs this whole category: match the lock to the risk, not to the bike. Kryptonite’s own guidance is to choose by where you lock and how long the bike is unattended — a rural ten-minute café stop and an overnight city street are not the same problem, and there is no single correct lock for both.
The uncomfortable truth underneath all of it: no lock is unbreakable. Every one is a time cost imposed on someone with tools. The goal is to be a worse target than the bike next to yours.
How this is funded: we earn a commission if you buy through our links, at no extra cost to you. It never changes which bike we recommend, and we will tell you plainly when we would skip one. Full disclosure.
Quick picks
Ranked on published specs, what the listing does and does not tell you, and who each one actually suits. Select a row to jump to the full write-up. We have not ridden these — here is exactly what we do instead.
#
Bike or gear
Best for
Price
1
Kryptonite Parkview U-Lock
The cheapest lock here from a manufacturer that publishes an honest security rating rather than the word 'heavy duty'. A 12mm hardened shackle and a cable for the front wheel covers the ordinary case.
The lock to buy if the bike is genuinely at risk. A 13mm shackle in a deliberately small U, because the less air inside the lock, the less room a thief has to get a tool in — that is the whole design argument for a mini.
Folding locks solve the U-lock's real-world problem, which is that a rigid U often does not reach around the thing you want to lock to. Nearly three feet of reach that folds down to something pocketable.
Four feet of 7mm hardened chain in a sleeve. Chains are the answer when you need to secure the frame and both wheels to something fixed, and no U-lock is long enough to do that.
A 12mm hardened shackle plus a 4-foot cable, which lets you lock the frame and both wheels to something solid. Kryptonite is the name thieves recognize, and that matters more than the specification.
A five-digit combination lock with no key to lose, at a price that makes it a reasonable second lock. Understand what you are buying: this is a deterrent against opportunism, not resistance against tools.
The cheapest lock here from a manufacturer that publishes an honest security rating rather than the word 'heavy duty'. A 12mm hardened shackle and a cable for the front wheel covers the ordinary case.
Who it is for: Low-risk parking: suburbs, workplaces, short stops in daylight.
What is good
+12mm hardened steel shackle — a real U-lock, not a cable pretending to be one
+Includes a 4ft cable for the front wheel, which is the usual thing that gets taken
+Kryptonite publishes a security rating for every lock, so you can compare honestly
+Cheapest genuine U-lock on this page
What you give up
−Low on Kryptonite's own security scale — this is not a big-city overnight lock
−The cable is a deterrent only; bolt cutters go through it in seconds
−No published weight on the listing
Skip this if. Skip this if you lock up in a dense city or leave the bike out overnight. Kryptonite's own guidance is to match the rating to the risk, and this rating is the wrong end of the scale for that.
Published specifications for the Kryptonite Parkview U-Lock
Type
U-lock with cable
Shackle
12mm hardened steel
Cable
4 ft
Locking
Key
Weight
Not published
Specifications read from the retailer listing on August 11, 2026. “Not published” means the listing does not state that figure — we do not estimate it.
#2Best security
Kryptonite Evolution Mini-7
The lock to buy if the bike is genuinely at risk. A 13mm shackle in a deliberately small U, because the less air inside the lock, the less room a thief has to get a tool in — that is the whole design argument for a mini.
Who it is for: City parking, or anywhere the bike is left for hours.
What is good
+13mm hardened shackle, near the top of Kryptonite's consumer range
+Small shackle opening leaves no leverage space for a jack or bar
+Includes a 4ft cable so the front wheel is covered too
+High on Kryptonite's published security scale, which is a comparable number
What you give up
−The small U is genuinely hard to get around some racks and posts
−Heavy — you feel this in a jersey pocket or a small bag
−Roughly four times the price of the Parkview
Skip this if. Skip this if you mostly stop for ten minutes at a time in quiet places. The weight and the awkward small shackle are a daily cost you pay for a risk you are not carrying.
Published specifications for the Kryptonite Evolution Mini-7
Type
Mini U-lock with cable
Shackle
13mm hardened steel
Cable
4 ft
Locking
Key
Weight
Not published
Specifications read from the retailer listing on August 11, 2026. “Not published” means the listing does not state that figure — we do not estimate it.
#3Best for awkward racks
Kryptonite Parkview Folding Lock
Folding locks solve the U-lock's real-world problem, which is that a rigid U often does not reach around the thing you want to lock to. Nearly three feet of reach that folds down to something pocketable.
Who it is for: Locking to awkward objects — thick posts, railings, wide racks.
What is good
+2.9 ft of reach, which goes around things a U-lock simply will not
+Folds flat into a frame-mounted case rather than hanging off the bars
+Riveted steel links are far more resistant than a cable of the same size
+Kryptonite rating published, so it is comparable against the U-locks
What you give up
−Folding locks have more joints, and every joint is a potential attack point
−Mid security rating — better than a cable, below a 13mm U-lock
−The mount rattles on rough surfaces unless you shim it
Skip this if. Skip this if you always lock to a standard bike rack. A U-lock is more secure for the same money when the geometry works, and on a proper rack it always does.
Published specifications for the Kryptonite Parkview Folding Lock
Type
Folding link lock
Length
2.9 ft
Locking
Key
Mount
Frame bracket included
Weight
Not published
Specifications read from the retailer listing on August 11, 2026. “Not published” means the listing does not state that figure — we do not estimate it.
#4Best for locking everything
Kryptonite Keeper 712 Chain Lock
Four feet of 7mm hardened chain in a sleeve. Chains are the answer when you need to secure the frame and both wheels to something fixed, and no U-lock is long enough to do that.
Who it is for: Locking a whole bike, wheels included, to a fixed object.
What is good
+4ft of chain reaches around frame, wheel and rack in one loop
+7mm hardened manganese steel links
+Fabric sleeve stops the chain marking the frame
+Kryptonite security rating published for honest comparison
What you give up
−Heavy — a chain this length is the heaviest option on this page
−7mm is at the lower end for a chain; bolt cutters are the known threat
−Awkward to carry on the bike without a bag or a rack
Skip this if. Skip this if you carry the lock in a jersey pocket. A 4ft chain is a bag or a rack purchase, and if neither exists, you will stop bringing it — which is worse than a lighter, weaker lock you actually use.
Published specifications for the Kryptonite Keeper 712 Chain Lock
Type
Chain lock
Length
4 ft
Link thickness
7mm hardened steel
Locking
Key
Weight
Not published
Specifications read from the retailer listing on August 11, 2026. “Not published” means the listing does not state that figure — we do not estimate it.
#5Best mid-range U-lock
Kryptonite Keeper U-Lock with Cable
A 12mm hardened shackle plus a 4-foot cable, which lets you lock the frame and both wheels to something solid. Kryptonite is the name thieves recognize, and that matters more than the specification.
Who it is for: Leaving the bike outside anywhere, ever.
What is good
+12mm hardened steel shackle — the published figure, which most locks hide
+Included 10mm x 4ft cable secures both wheels, not just the frame
+Mounting bracket so the lock rides on the bike, not in a bag
+Kryptonite's reputation is a deterrent in itself
What you give up
−Heavy — noticeably so on a bike you were choosing by weight
−The Keeper is Kryptonite's entry lock, not their highest security rating
−The cable is a deterrent against opportunists, not a serious barrier
Skip this if. Skip this if the bike lives indoors and never gets left in public. It is a lot of weight to carry for a risk you are not taking, and the money is better spent on a floor pump and lights.
Published specifications for the Kryptonite Keeper U-Lock with Cable
Shackle
12mm hardened steel
Cable
10mm x 4ft braided steel
Mounting bracket
Included
Security rating
Not published
Weight
Not published
Specifications read from the retailer listing on July 23, 2026. “Not published” means the listing does not state that figure — we do not estimate it.
#6Best keyless second lock
Sportneer Combination Chain Lock
A five-digit combination lock with no key to lose, at a price that makes it a reasonable second lock. Understand what you are buying: this is a deterrent against opportunism, not resistance against tools.
Who it is for: Café stops within sight, and securing a second bike at home.
What is good
+No key, which removes the most common way people get locked out of their own bike
+Five-digit combination is a real search space, not the four-digit minimum
+Available in several lengths up to 4ft
+Cheap enough to own a second one for the wheel
What you give up
−A chain of this gauge is cuttable with hand tools in well under a minute
−The listing does not publish link thickness or hardening
−Combination dials seize with grit and winter salt
Skip this if. Skip this if this will be your only lock and the bike is worth more than a few hundred dollars. Match the lock to what is being protected — this one is protecting against someone walking past, not someone arriving with a plan.
Published specifications for the Sportneer Combination Chain Lock
Type
Combination chain lock
Length options
3.2, 3.6 or 4 ft
Locking
5-digit combination
Link thickness
Not published
Weight
Not published
Specifications read from the retailer listing on August 11, 2026. “Not published” means the listing does not state that figure — we do not estimate it.
What the security ratings mean
Kryptonite publishes a rating for every lock they make, from 1 (deterrent, for low-risk situations such as trail stops) to 10 (ultimate security, for dense urban areas). That is genuinely useful, because it lets you compare two locks from the same maker honestly rather than by reading the words “heavy duty” on both.
The independent version is Sold Secure, a British testing house that attacks locks with real tools for a fixed time and awards Bronze, Silver, Gold or Diamond. Its ratings appear on some locks sold in the US and are the closest thing to a neutral standard. Where you can find a Sold Secure rating, trust it over a manufacturer’s number.
What to do with this: pick a rating band by your situation, then choose within it on weight and shape. Do not buy the highest rating available — you will stop carrying it, and the lock you left at home has a security rating of zero.
The four lock types
U-locks (D-locks)
A hardened steel shackle in a rigid U. The best security per dollar and per gram, because there is very little to attack and almost no room to insert a tool. A smaller U is more secure, not less: less air inside means less leverage space. The trade is that a small U often will not reach around a thick post.
Folding locks
Riveted steel plates that fold flat into a frame-mounted case. They solve the U-lock’s real-world problem — reach — at the cost of having many joints, and every joint is somewhere to attack. Mid security, excellent practicality.
Chains
The only type long enough to secure the frame and both wheels to a fixed object in one loop. Heavy: a 4ft chain is the heaviest thing on this page and needs a bag or a rack. Link thickness is the spec that matters, and the honest threat is bolt cutters.
Cables
Not on this page as a primary lock, deliberately. A cable is cut in seconds with hand tools. It is fine as a secondary loop through a front wheel — which is exactly why several U-locks here include one — and it is not a lock.
How to lock up, which matters as much as what you buy
A good lock used badly is a bad lock. Four rules:
Lock the frame to something fixed. Not the wheel alone — quick-release wheels come off in seconds and you will come back to a wheel locked to a rack.
Fill the U. Empty space inside the shackle is where a jack or a bar goes. Get frame, rack and wheel inside it so there is no room left.
Keyhole facing down, lock off the ground. A lock resting on pavement can be smashed against it; a keyhole facing up collects rain and freezes.
Check what you locked to. Scaffolding poles lift out. Signposts unbolt. Wooden fences saw. The rack is only as good as its anchor.
Two locks, and why
The standard advice for genuinely high-risk parking is two locks of different types — typically a U-lock and a chain or folding lock. This is not about doubling the strength. It is that different locks need different tools, and a thief carrying an angle grinder for the U-lock may not also be carrying bolt cutters for the chain.
For most readers of this site, that is overkill. It becomes reasonable when the bike is worth more than about $1,000 and lives on a city street.
Register the bike, and photograph it
Free, takes ten minutes, and it is the only thing on this page that helps after a theft. Record the serial number — stamped underneath the bottom bracket shell, where the cranks pass through the frame — and keep a photograph of the whole bike. Recovered bikes are routinely unreturnable because nobody can prove ownership. Our storage and security guide walks through the whole ten minutes, and covers the more important point that most bikes are stolen at home rather than out in the world.
What we would spend
About $23 on the Parkview U-lock for ordinary suburban parking, or about $92 on the Evolution Mini-7 if the bike is genuinely at risk. Both include a cable for the front wheel, which closes the most common gap.
If your bike will be carrying the lock, look at bags at the same time — a 4ft chain in a jersey pocket is not a plan.
We have not ridden these bikes. Every site in this category says it tested twenty of them. We have not tested any, and we say so. What we did instead: read the manufacturer listings and manuals, compiled the published specs, worked out the real out-the-door cost, and checked live availability and price. Here is exactly how that works.
Questions people actually ask
What kind of bike lock should a beginner buy?+
A U-lock with a cable for the front wheel, from a brand that publishes a security rating. It gives the best security per dollar and per gram, and the included cable closes the most common gap — a quick-release front wheel left unsecured. Choose the rating band by where you park, not by what the bike cost.
Are expensive bike locks worth it?+
Only in proportion to the risk. A high-rated lock is heavier and more expensive, and a lock heavy enough that you stop carrying it has a security rating of zero. Match the lock to where the bike is left and for how long — that is the manufacturers' own advice, and it is right.
What does a bike lock security rating mean?+
Manufacturers like Kryptonite publish their own 1-to-10 scale, where 1 is a deterrent for low-risk stops and 10 is for dense urban parking. It is comparable within a brand. The independent version is Sold Secure, which attacks locks with real tools for a fixed time and awards Bronze, Silver, Gold or Diamond — trust that over a maker's own number where you can find it.
Should I use a cable lock?+
Not as your only lock. A cable is cut in seconds with ordinary hand tools. It is genuinely useful as a secondary loop through a front wheel or a saddle, which is why several U-locks ship with one, but treat it as an accessory rather than as security.
How do you lock a bike properly?+
Lock the frame — not just a wheel — to something genuinely fixed, and fill the U so there is no empty space for a tool to lever against. Keep the lock off the ground and the keyhole facing down. Then check the anchor: scaffolding lifts out, signposts unbolt, and wooden fences saw.
Do I need two bike locks?+
For most people, no. Two locks of different types is the standard advice for high-risk city parking, and the logic is that different locks need different tools — someone carrying an angle grinder for a U-lock may not also be carrying bolt cutters for a chain. It becomes reasonable when the bike is worth over about $1,000 and lives outdoors.
Sources
Specifications come from the manufacturer or the retailer listing, dated. Where a figure is not published, we say so rather than estimating it.
