The Best Locks for E-Bikes

How much to spend

The old rule of thumb is 10 percent of the vehicle's value, and it survives because it roughly tracks reality. On a $2,000 e-bike that is a $200 lock, which sounds absurd until you price the replacement.

A cheap cable lock is not a lock. A pair of hand cutters goes through one in a couple of seconds, silently, and any thief working bikes carries them. A cable is for stopping an opportunist walking off with an unattended bike in front of a shop, and it should never be the thing standing between you and a $2,000 loss.

What to look for

Sold Secure is the rating that means something, and Diamond is two different ratings. It is an independent UK programme that pays testers to attack locks with real tools for a fixed time, grading Bronze, Silver, Gold and Diamond. The part almost nobody explains is that Sold Secure runs separate ladders, and the two that matter here are Pedal Cycle and Powered Cycle. Both have a Diamond tier and they are not equivalent: Powered Cycle Diamond is the harder one, reserved for locks with real angle-grinder resistance. So a plain "Diamond" sticker can mean the bicycle ladder, which a grinder-vulnerable lock still passes. For an e-bike parked outside, the words to look for are Sold Secure Powered Cycle Diamond. The important part is that the maker does not award it to themselves. A lock with no third-party rating is asking you to take its word, and marketing words like "maximum security" or "hardened" carry no defined meaning at all. Buy a rating, not an adjective.

Angle-grinder resistance is the newest and most important distinction. For years the security conversation was about bolt cutters and leverage. Then battery angle grinders got cheap, small and quiet enough to carry, and they cut through almost any conventional hardened steel in under a minute. A handful of locks now use abrasive-resistant composite layers that destroy cutting discs rather than resisting them, which turns a one-disc job into a several-disc job in public. Two of the picks here do this. If you park on a street overnight in a city, this is the feature that has actually changed since your last lock.

Shape decides what you can lock to, and that decides everything else. A small U-lock is the most secure shape because it leaves almost no room to insert a jack or a pry bar, but it only reaches a slim post or a proper bike stand. A chain reaches around fat street furniture and awkward racks, at the cost of weight and some leverage exposure. Folding locks split the difference and are the easiest to carry. Before you buy, look at where you actually park, because the most secure lock in the world is useless if it will not close around the only thing there.

Two different locks beat one expensive lock. Thieves carry the tool for the lock they expect. A U-lock through the frame and rear wheel plus a chain or cable through the front wheel means one tool no longer finishes the job, and switching tools in public is exactly the exposure they are trying to avoid. If your budget is $250, two locks at $125 usually buys more real delay than one at $250.

Lock the frame to the immovable object, and get a wheel in there too. The most common expensive mistake is locking only a wheel. Quick-release wheels come off in seconds and the rest of the bike leaves without them. Put the shackle through the rear triangle and rear wheel where possible, fill as much of the U as you can with bike and rack so there is no room for tools, and keep the keyhole facing down and away from the ground.

Take the battery with you when it comes off. A removable battery is a large fraction of the vehicle's value, it is trivially resold, and it is usually held by a lock that is a convenience feature rather than a security one. Carrying it also makes the bike much less attractive to ride away, and it is the single easiest theft deterrent available on most e-bikes.

Register the bike and photograph the serial number now. Recovery rates are poor mostly because owners cannot prove which bike is theirs. The serial is normally stamped under the bottom bracket. Photograph it, note it somewhere you will still have after the bike is gone, and register it with a national database. This costs you five minutes and is the difference between a recovered bike and a bike the police cannot return. Pair it with a tracker if the bike lives outside.

The anti-theft guarantee on the box is not insurance

Several lock makers advertise an anti-theft guarantee, and it causes real confusion. The common assumption in rider forums is that the guarantee just replaces the lock, which would be worthless: if the lock failed, the bike is gone, and a free replacement lock protects a bike you no longer own.

That assumption is wrong, but the instinct behind it is right. These programmes do pay toward the bike. They are just so tightly conditioned that most real thefts fall outside them.

Kryptonite's Anti-Theft Protection Offer is the oldest and most documented example, so it is worth reading closely as the model for the category. Its own terms state plainly that it is not bicycle insurance and has no affiliation with an insurance company. Here is what it actually does.

What it pays. If the lock itself is forced open or broken, it pays the lesser of your bike's base cost, excluding tax and accessories, or your insurance deductible. That is capped at a maximum set by which lock you bought, so the cheap lock carries a small cap and the expensive one a larger cap. Note the second half of that: if you have insurance, the programme pays your deductible rather than your bike.

What you have to do first. Register within a short window of buying the lock, pay a registration fee, and supply an itemised lock receipt from a real retailer, the key number stamped on your key, and your bike's make, model, base cost, serial number and bill of sale. Miss the window or the paperwork and there is nothing to claim against.

What you have to do after a theft. Report to police within 72 hours. Notify the company within 7 days. Then, within 90 days, mail them the broken lock. That last requirement is the one worth pausing on, and it is where the forum instinct is closest to correct: if the thief carried the lock away with them, or you cannot produce the broken pieces, the claim has no evidence behind it.

When it does not pay at all. The terms are explicit on several points that describe extremely common thefts:

• If the rack, post or object you locked to was cut instead of the lock, it does not pay. The lock has to be the thing that failed.
• If the bike frame was cut, it does not pay.
• Cables are never covered, including the cable bundled with a covered U-lock.
• The e-bike battery is excluded, which on many e-bikes is a large share of the value and a target on its own.
• Attempted thefts and recovered bikes are excluded, as is vandalism that does not result in a theft.
• Coverage runs one year from registration unless you pay to extend it.
• There are geographic carve-outs. In New York City, only the maker's New York series locks are covered in Manhattan.

None of this makes the guarantee worthless. It is a genuine, if narrow, refund, and it costs little. But it is a refund tied to one specific failure mode, not cover for losing your bike, and it should not change which lock you buy or how carefully you lock up. Buy the lock on its security rating. Treat the guarantee as a small bonus you register for on the day you buy, because the registration window is short and there is no way to add it later.

One thing to check before you register: because the payout can be limited to your deductible, the guarantee and an actual insurance policy interact. Work out which one is really carrying your risk before you assume either of them is.