Bike Locks for Chicago: What to Buy and How to Lock

The lock is the cheapest part of a bike and the most important. In Chicago a single weak lock is an invitation. What follows is how to choose one, how to use it, and where it will hold.

Start with the lock type

U-lock. This is the primary lock. CDOT says U-locks are strong, and better ones come with theft warranties.¹ Bike Index adds a floor on price: use a U-lock that costs at least $40, because cheaper and older U-locks can often be broken without any tools.²

Cable lock. Do not rely on one. Bike Index says cable locks should never be the primary means of locking a bike in a city.² They are especially vulnerable to being cut quickly.³

Two locks. Bike Index considers two U-locks, or a U-lock and one heavy-duty cable, the minimum required in large cities to keep a bike secure.² It also advises aiming for the hardest bike to steal on the rack.²

Buy the highest-quality lock you can afford.¹ Then read the maker’s warranty and replacement policy before you need it.¹

Locks fail, so layer them

Locking is not a guarantee. In Bike Index’s 2023 survey, 59% of stolen bikes were locked at the time of theft.³ Of those, 35% used cable locks, the easiest to cut, and 26% used U-locks, which are more secure but still vulnerable to certain attacks.³

At outdoor racks the numbers are starker. In the same survey, 95% of bikes stolen from outdoor racks were locked, and even U-locks can be cut with the right tools.³

The remedy is layers: double the locks and lock to something solid. Bike Index also suggests motion alarms.³

How to apply the lock

The frame and both wheels must be secured.² The method that gets there:

1. Loop the U-lock through the rear triangle so it captures the rear wheel, the frame and the rack in one pass.⁴
2. Deal with the front wheel by one of three methods: remove it with the quick release and set it next to the rear wheel, use locking skewers, or use an accessory cable.⁴
3. Lock the seat to the frame with a locking bolt or small chain.⁴

Locking skewers replace the quick-release axle that holds a wheel to the frame.⁴

CDOT gives the same instruction for quick-release wheels: lock through the frame and a wheel, and add a cable or a second U-lock for the other wheel.¹ Bike Index recommends a combination of locks that secures both wheels to the frame and to the object, with a U-lock through the rear wheel and triangle.³

Remove lights, bags and quick-release parts before you walk away.¹

What to lock to

Lock to a bike rack, or to a parking meter or sign pole that is firmly affixed, with bolts covered in concrete. These are the most secure places.¹

Be wary of the “sucker pole,” a sign post loosely bolted down that can easily be removed.¹ Bike Index says to tug on whatever you are about to lock to, since signposts can be unbolted and some are already unattached.²

Avoid private property.¹

Do not trust the crowd or the camera. Bike Index says not to rely on foot traffic, because many thefts occur under the cover of crowd activity. It also says security footage is rarely of much use once a bike is gone.²

Where the racks are

Chicago has installed over 15,000 public bike racks and over 80 on-street bike corrals.⁵ The standard CDOT rack is a galvanized steel inverted U, suitable for nearly all bike parking.⁵ A corral holds 10 or more bikes in the space of one car.⁵

CTA stations are a second source. The CTA installs bike racks outside most L stations, and many stations also offer sheltered or indoor parking for added security and weather protection.⁶ On a CTA bus, you may lock the front wheel to the frame, but not to the bus rack.⁶

For a map of where to park downtown, see bike parking downtown.

Garages, porches, hallways

A locked room is not a locked bike. Lock a bike kept in a garage or on a porch.¹ CDOT says Chicago garages are less secure than basements or living spaces.¹ Bike Index says to lock to an immovable object even in a “secure” place, since many bikes are taken from garages and store rooms.²

Then register it

A lock slows a thief. A serial number brings a bike home. Record the serial number, keep a photo of you with the bike, and register it with the Chicago Police Department.¹ The next steps, if it is taken, are in stolen bike in Chicago, and the national and local numbers are in bike theft in Chicago. Start at the commuting hub for the rest.