Bicycle pedals are made to be easily changed. However, this is not always the case. Bike pedals are subjected to dirt, water, grit, grime, mud or a combination of all of these. It's no wonder they occasionally get stuck. There's no magic bullet when it comes to stuck pedal removal. It's more an issue of brute strength.
Politcally Correct Pedals
It could be said that "politics" are involved with changing stuck pedals as there is a definitive right and left spin on things. Never attempt to remove a pedal before determining this fact. Due to the forward motion of the pedal, right and left threads have been established on pedals. For example, the pedal on the right turns counterclockwise for removal, just like any other ordinary thread. And just like the other side of the aisle politically, the pedal on the left is exactly opposite and turns clockwise for removal. The clockwise threads on the left side counteract the forward motion of the pedal. In other words, if the threads were not reversed on the left side, the pedaling motion would unscrew the pedal while you're riding the bike. Bikers use a simple rule to remember what direction to turn the pedals to remove them: right is right and left is wrong. If you get confused, there's typically a stamped letter on the pedal or nut to remind you whose side you're on.
Stand and Deliver
Stand the bike against the wall with the pedal you want to remove facing away from the wall and forward to the front of the bike. Determine which direction to turn the pedal to remove it and place a 15 mm wrench on the nut between the pedal and the crank arm so that the wrench is roughly horizontal, if possible. Push down on the wrench to loosen the pedal. If the pedals on both sides turn, push the bike sideways into the wall to stop the other pedal from turning or get someone to help you stop the pedals from turning by holding onto the opposite pedal. If you can't budge the pedal, don't force it too much, this could result in rounding off the nut and making it more difficult to remove.
Get a Bigger Hammer
Tap on the end of the wrench with a hammer or mallet if the pedal won't loosen. Give it a few good whacks, and it should loosen enough to remove it with the wrench. If that doesn't work, get your hands on a 15 mm spanner wrench. This wrench is longer than normal, with jaws that will grip the nut more securely than ordinary wrenches. Place the spanner wrench on the nut and use enough force to loosen the pedal. The extra length might be all you need. If it still doesn't loosen, try adding a piece of pipe to the end of the spanner for even more leverage. If that doesn't work, tap on the pipe and spanner together with a mallet to loosen the pedal.
If All Else Fails
If nothing else works, tip the bike on its side. Spray the pedal axle and nut with penetrating oil and let it soak overnight. Sometimes that's all it takes, and the pedal unscrews easily the next day. Some professionals use heat to loosen pedals, but that involves running a torch over the pedal axle and nut. This might work for professionals, but you can damage your bike using an open flame on it. It's best to leave that method to the professionals. Try running a hair dryer over the nut until it's hot, after you've let the penetrating oil soak in overnight and wiped off the excess. Use the spanner or ordinary wrench to remove the pedal. If you have tried everything, it might be beneficial to take the bike to a bike shop and have them do it for you at a minimal cost. Always add grease to the pedal axle before installing the new pedal. It will help prevent it from sticking in the future.
Specializing in hardwood furniture, trim carpentry, cabinets, home improvement and architectural millwork, Wade Shaddy has worked in homebuilding since 1972. Shaddy has also worked as a newspaper reporter and writer, and as a contributing writer for Bicycling Magazine. Shaddy began publishing in various magazines in 1992, and published a novel, “Dark Canyon,” in 2008.