Make sure to use a cheap pen, as opposed to a more fancy kind. You need to find a pen that has an end cap that pops off, rather than one that screws off or can’t be easily removed.
If the tube of the pen doesn’t fit inside the keyhole, it won’t work to open the lock. Find a pen that fits inside keyhole after its cap has been removed.
Use your wrist rather than your whole arm to get the energy needed to push and twist.
If you are unsure of whether the lock has opened, pull at the bar of the U-lock to check. If you are applying pressure, you should feel the lock open.
Canned air contains the compressed chemical difluoroethane, which will cool the lock to around -13 degrees F (-25 degrees C).
Position the U-lock so that the bar of the U-lock is lying flat on the ground or is against a stable surface like a door or the bar of the bike rack.
Be sure to aim the spray radius at the keyhole, where you will focusing your hammering.
Keep your fingers away from the place that you are hammering. Also try to keep the U-lock stable and in position as you hammer. Don’t be alarmed as you see the white powder on the U-lock come off in a mist as you begin to hammer.
Be patient, as it may take several minutes of hammering to break the U-lock. Dispose of the remains of the lock when you are finished.
Put on work gloves to protect your hands, as well as goggles to stop any flyaway material from getting in your eyes. Don’t wear any loose clothing or jewelry when you operate the angle grinder. Make sure that you are using the right sized disc for the grinder and that the grinder is able to go up to maximum speeds. If your U-lock is locked but not attached to anything, clamp it with a vice attached to a table. If the lock is fastened around a bicycle, adjust it so that when pressure is applied to it, it doesn’t move but stays in relatively the same place.
Be very slow and deliberate when you use the angle grinder. Don’t push or exert force with the grinder. Just hold the blade against the lock and wait as it chips away. If exert force while you cut, you will cut through the U-lock and then push angle grinder past it to cut whatever is behind the U-lock.
