How do I stop my bike being stolen, and what do I do if it is?

One page in this library answers this. If you ride to work, a stolen bike takes your way of getting there with it. Many people say the quick way to protect a parked bike is to leave it in its hardest gear, so a thief cannot pedal away; some people who ride say it does not work, and the police pages the library read are about locks, parking and written details, and none of them suggests a gear setting.

Lock the frame, and the wheels if you can, to something fixed every time you leave your bike, even for a minute, and do not rely on a gear setting to stop a thief. Lock your bike to something fixed, even for a minute puts one safety line first. If you find your stolen bike for sale, Police Scotland says do not try to buy it back, because you could put yourself in danger, and to call 101, the police non-emergency number in the UK, and the police will tell you what to do next. In the US, ask your local police what to do before you contact the seller; the page has no US police page to quote on it. Some people warn that setting a trap for a thief, or planting evidence on a suspect, is illegal and dangerous. If a theft is happening and someone could be hurt, or anyone is in danger, call 911 in the US or 999 in the UK.

Seattle Police put it this way: “Never leave your bicycle unlocked, even for a minute!” Police Scotland says to lock your bike up every time you leave it. A hard gear is not a lock: some people who ride say a thief can lift or carry the bike, or run it along and jump on, or shift to an easier gear as soon as it is rolling, and one person says an owner on foot cannot outrun a thief who is pedalling, whichever gear the bike is in. The page cannot say whether the trick slows a thief by a second or two. Seattle Police say: “Remember that locks are only a deterrent,” and that “The majority of the bicycles stolen are unlocked or locked with poor quality cable locks!”

Police Scotland, Northern Ireland’s police service, Avon and Somerset Police and Seattle Police all say to lock the frame, and a wheel or both wheels, to a stand or a solid fixed object. What counts as fixed matters. Northern Ireland’s police service says: “Do not lock your bike to an open-ended structure such as a signpost – thieves just lift the bike over the top of it,” and “Avoid locking your bike against a gate or wall, thieves will often use leverage against the wall or gate to break the bike lock.” It says some cycle racks are security tested and others are not, so be wary, and that you should lock the bike as close to the stand as possible, so a thief has little or no room to work, and keep the lock off the ground; Police Scotland and Avon and Somerset Police say the same about the ground. Police Scotland says to use two locks of different types if you can, and Northern Ireland’s police service says double locking is the best protection, though it is not always possible, and that one approved high-security lock protects better than two untested ones. Take or fix the parts that can be taken: Seattle Police say to remove quick-release parts altogether and bolt them on, Northern Ireland’s police service and Avon and Somerset Police say locking skewers or nuts make it harder to take seats and wheels, and Police Scotland says to remove things that cannot be locked, such as lights, pumps, water bottles, bags and saddles.

Seattle Police say: “We recommend that you use a solid steel U-Lock, as these locks are very difficult to cut if secured properly.” A U-lock is called a D-lock in the UK. They say a flexible lock should be at least 3/8 inch in diameter, and: “Never secure your bicycle with a cheap lock.” Avon and Somerset Police advise against cable-style locks and combination locks, because thieves can defeat them quickly, while Police Scotland says to choose a Sold Secure bike lock, one tested to a security standard, and to make sure it is a D-lock or a thick cable lock; the police pages differ on cable locks. If money is tight, Police Scotland’s guide is to buy the best lock you can afford and spend about a tenth of the bike’s cost on it, and Northern Ireland’s police service says it can take thieves as little as a few seconds to cut through some locks that have not met the Police Preferred Specification, and tells you to look for the Secured by Design logo. The page cannot say which lock at which price is strong enough for your bike.

Park where people can see it. Seattle Police say to park in well-lit and highly traveled areas and, when possible, not to leave a bike locked outside overnight; Police Scotland says to lock in a busy, well-lit place, in view of people or cameras, and to change your routine. Lock it at home too: Police Scotland says more than half of all stolen bikes are taken from the owner’s property, and Avon and Somerset Police say to lock your bike at home, even in a garage, a flat or halls of residence, and to consider a ground anchor fixed to a wall or concrete floor.

Write it down before it is stolen. Northern Ireland’s police service says to write down the make, model, size, colour, frame number and any distinguishing features, and to take a photo. The frame number is on the underside of the bike, in the part of the frame that the pedal arms turn in, called the bottom bracket: Police Scotland says to record the serial number there, Avon and Somerset Police say it is usually stamped into the metal on the underside of the bottom bracket shell, and the Police Service of Northern Ireland says it is normally found underneath the bike between the pedals or where the back wheel slots in. Photograph it, and write it somewhere you will find it. One person says a picture of you with the bike, and a mark that only your bike has, help prove the bike is yours when you claim on insurance or report the theft. On registering, Northern Ireland’s police service says to register your bike on a secure national database that Secured by Design recognises, and that the police will check these databases if they find bikes in the possession of a criminal or left in the street; Seattle Police say to consider registering your bicycle, taking photos and knowing the serial number, because this can make it easier to return your bike if it is stolen. One person, writing about the US, says police there rarely check these private databases and rely on national crime systems, and the page cannot say what your local police do, so ask them.

If it is stolen, Police Scotland says to report it to the police and ask for a crime reference number, to tell your insurer ideally within 24 hours, to check websites where bikes are sold in case yours is listed, and to tell local bike shops about your bike; it says you will need your insurance policy number, the crime reference number, and proof of ownership or purchase, and that if you do not have bike insurance you should check whether your home contents insurance covers it. In the US, Seattle Police say that after an online report is approved, the official police report number it emails you is the number to file with your insurance company, and that its online reporting is not monitored live, so dial 9-1-1 if you need an immediate response; other police departments have their own way to report. Some people warn that getting the bike back yourself carries legal and safety risks, and one person says the police are slow or will not act on a single bike while another says the police help when you give a specific location. On a tracker, the page cannot say whether one is worth it: some people say a tracker hidden inside a metal or carbon frame may not get a signal, and one person says that knowing where the bike is does not mean you get it back.

Who this is not for. If you have an e-bike, Northern Ireland’s police service says that if you leave it in public parking for any length of time you should take the battery with you, because a thief can easily overcome battery locks, and Avon and Somerset Police say theft of e-bike batteries is on the increase; for a high-value bike, both forces point to higher-rated locks. If you are buying a second-hand bike, Avon and Somerset Police say to make sure the seller owns it, to ask for a receipt, and to check the frame number online to see if it has been reported stolen. If you have nowhere safe to lock a bike overnight, the page cannot fix that. Nothing here promises that a lock, a registry or a photo will stop a theft or get a bike back, and the page cannot tell you what your insurance policy covers: ask your insurer. The page is built on police advice as read in October 2026, and other police forces may say different things. If a theft is happening and someone could be hurt, call 911 in the US or 999 in the UK.