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How to Unlock a Bike Lock Without Keys? – 3 Easy Ways

Fact checked by Teddy B.Miller

how to unlock a bike lock without keys

If you own a bike, chances are you also own a bike lock so you can leave your bicycle unattended when running other errands. Whatever kind of bike lock you invested in, have you ever thought about what to do if suddenly you have a problem with a lost key for bike U lock?

Don’t call a locksmith yet; you have the power to resolve the issue on your own if you just keep in mind the techniques that will be discussed in this article.

Read on to learn how to unlock a bike lock without keys!

Use the Decoding Method

The decoding method is used for bike locks that require a combination of numbers or letters or sometimes both to unlock.

These bike locks are considered less secure because the code can be known to other people, and there is no need for a key to make this work.

This is usually used on cable locks and U-lock or D-locks. Additionally, some may forget the combination they are using, resulting in a dilemma of how to unlock it. Here are the steps on how to remove a bike lock without a key:

Steps to follow:

  • Step 1: First, pull the bike lock apart with enough pressure.
  • Step 2: Second, rotate each wheel carefully for each number, then feel the numbers that have more pressure when being turned.
  • Step 3: Third, write down the numbers which stick or which you can feel has resistance when being turned.
  • Step 4: Fourth, do the same steps for the succeeding dials until you finish them all.
  • Step 5: Fifth, be patient in mixing and matching the combination you have written down until you find the correct code. By this time, the cable will pull free.

Use the Bypass Method


Bypass method is using a simple tool to compromise the lock’s bolt for it to open. This is a good solution in resolving a lost bike lock key because it will not damage the lock.

1. With a ball-point pen

  • Step 1: First, remove the tip of a plastic pen, preferably a Bic pen or something with the same diameter.
  • Step 2: Second, insert the pen into the keyway and then twist.

2. With a Hammer and air spray

This looks like an odd combination but this is one effective trick to break bike lock. Air sprays have compressed air in it that will make the lock freeze and become weak. Wear hand gloves to protect your hands in extreme cold while performing this method.

  • Step 1: First, lay down the bike so you can position the bike lock against the ground.
  • Step 2: Second, spray directly the air spray on one side of the bike u-lock or through the keyhole of the lock for at least 30 seconds.
  • Step 3: Begin hammering the lock once you see the surface of the lock turned white due to chemical reaction. By this time, the lock is now brittle enough to be destroyed.

3. With a Padlock Shim

A padlock shim is a tiny piece of material usually made from metal, stone, or wood. It is available in hardware, costs an average of $20, and is available in different sizes to cater to the varying sizes of locks.

  • Step 1: First, find a padlock shim that fits most closely to the lock you will open.
  • Step 2: Second, insert the padlock shim between the shackle and the lock body by gently rocking sideways for it to be pushed down into position.
  • Step 3: Third, if your lock is double-bolted, do the same thing to the other side. Once the padlock shim slides the bolt out of the shackle, the lock will unlatch.

If you do not have a commercial padlock shim, you can make your own by using a tin can.

  • Step 1: First, cut a strip of a tin can about one inch by two.
  • Step 2: Second, make a little mark forming the shape of the shim blade.
  • Step 3: Third, fold it up and form a curve in it to make insertion easier.
  • Step 4: There you have it; this DIY lock shim is cheaper but works just the same as the commercial ones.

3. With a lock pick

This is probably the oldest method to unlock a U lock without a key. You’ll just need a lock pick and tension wrench. These materials usually cost an average of $50 each.

Steps to follow:

  • Step 1: First, insert one tension tool at the bottom of the lock (keyhole) and apply a small force to the cylinder.
  • Step 2: Second, insert a lock pick at the keyhole and feel the key pins.
  • Step 3: Third, lift each pin while maintaining the tension on the wrench so the pin will not fall back down.
  • Step 4: Fourth, insert the tension wrench and nudge it up every time you are able to push past a pin and make it click.
  • Step 5: Fifth, repeat all the previous steps until all of the pins are settled.
  • Step 6: Lastly, turn the tension wrench slowly to unlock the key open.

Use the Cutting Method


This method should be your last resort on how to open a bicycle lock without a key as this will permanently damage your bike lock.

Here are some materials you may use to break a bike lock cable. Be careful in doing these steps as some bike lock cables are sturdy and you may have difficulty breaking them.

1. With a hacksaw

  • Step 1: First, hold the cable firmly with your non-dominant hand.
  • Step 2: Second, use your dominant hand in cutting back and forth the material on the weakest part of the lock.
  • Step 3: Third, use hard consistent pressure in order to break the lock completely.
  • Step 4: With a cable cutter

Another way to break a bike lock is using a cable cutter. This is specifically made for cutting properly specific metals such as aluminum and copper.

  • Step 1: First, find the plastic coating of the cable, then make a small trim around it.
  • Step 2: Second, remove the portion of the plastic coating by squeezing and holding it down so that you can focus mainly on breaking the cable.
  • Step 3: Third, apply firm pressure to the cable as you cut it through.
  • Step 4: Fourth, wobble back and forth the cable cutter until the cable breaks.

2. With an angle grinder

An angle grinder, a portable power tool used for heavy cutting, polishing, and grinding purposes can be electrically powered or battery operated to function. This tool can break almost all material in no time so be very careful. Use goggles to protect your eyes from the flyaway materials that will be scraped off from the lock.

  • Step 1: First, use the right-sized disc for the grinder.
  • Step 2: Second, turn on and position the grinder at an angle of 30 degrees and a few inches away from the lock.
  • Step 3: Hold the blade against the lock using both hands. Let the blade cut through the lock without using much effort or pushing it.
  • Step 4: Turn off immediately the angle grinder once you’re done unlocking your bike lock.

You also can use a bolt cutter to cut your lock, here’s how!


There are several methods on how to unlock a bike lock without keys. These are the decoding method, the bypass method, and the cutting method.

These techniques differ from every type of bike lock you’re using. So instead of going through the hassle of unlatching the lock of your bike without keys, why not pick a bicycle lock thoroughly first?

After all, picking a bike lock is one good way of securing your two-wheeled companion.

If you find this article informative, please take the time to relay it to your friends. Thank you for reading!

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