You need a crank puller tool and an Allen wrench or socket wrench to remove the crank from your bike
Removing a bicycle crank requires two tools: a crank puller (a threaded tool that costs $15 to $40) and either an Allen wrench or socket wrench that fits your crank bolt. The process takes 10 to 20 minutes once you have the right tools. Most cranks are held on with a single bolt on the non-drive side (the left side of the bike), though some older bikes use a cotter pin instead.
The crank puller works by screwing into the crank arm, then using a center screw to push the crank off the spindle. Trying to hammer or pry the crank off without this tool will crack the crank or damage the spindle, so the puller is not optional.
Key Takeaways
- A crank puller is the only safe way to remove a crank; hammering or prying will damage your bike.
- You must remove the crank bolt on the non-drive side (left) first, using an Allen wrench or socket wrench.
- Thread the crank puller into the crank arm hole, then turn the center screw clockwise until the crank slides off.
- If the crank bolt spins without loosening, hold the spindle steady with a second wrench on the opposite side.
Locate and remove the crank bolt
Look at the left side of your bike (the side without the chainring). You will see a bolt or nut in the center of the crank arm where it meets the frame. This is the crank bolt. Use an Allen wrench or socket wrench to turn it counterclockwise and loosen it completely — do not just loosen it partway.
If the bolt spins without coming loose, the spindle is turning with it. Hold a second wrench on the opposite side of the spindle (the right side, inside the frame) to keep it still while you turn the bolt. Once the bolt is fully removed, set it aside in a safe place.
Thread the crank puller into the crank arm
The crank puller has a threaded shaft that screws into the hole where the crank bolt was. Line up the puller with the hole and turn it clockwise by hand until it is snug — do not force it or cross-thread it. The puller should sit flush against the crank arm.
Once the puller is threaded in, you are ready to push the crank off. Do not over-tighten the puller before you start turning the center screw, or you may strip the threads inside the crank arm.
Turn the center screw to push the crank off
The crank puller has a center screw that sticks out from the middle. Use an Allen wrench or wrench that fits this screw and turn it clockwise. As you turn, the screw pushes against the spindle and forces the crank arm off. You will feel resistance — keep turning steadily until the crank slides free.
The crank will come off suddenly once the spindle releases, so be ready to catch it or let it fall safely. Do not turn the center screw so hard that you strip it; steady pressure works better than force.
Remove the crank puller and inspect the spindle
Once the crank is off, unscrew the crank puller by turning it counterclockwise and remove it from the crank arm. Look at the spindle where the crank was attached. It should be smooth and free of rust or damage. If you see corrosion, wipe it clean with a dry cloth or fine steel wool.
If you are removing both cranks (for example, to replace the bottom bracket), repeat the same steps on the right side. The right crank usually requires a different crank puller designed for that side, so check your tool before you start.
Common mistakes that damage your bike
The most common mistake is trying to remove the crank without a puller — using a hammer, mallet, or pry bar will crack the crank arm or bend the spindle beyond repair. Another mistake is loosening the crank bolt but not removing it completely before using the puller; the bolt must be fully out or the puller will not work.
A third mistake is cross-threading the puller into the crank arm. If you feel the puller binding or grinding as you screw it in, stop when ready and back it out. Forcing it will strip the threads and make the crank impossible to remove. If this happens, you may need to drill out the crank arm or take the bike to a shop.
What to do if the crank is stuck
If the crank will not come off even with the puller turning steadily, the spindle may be corroded or the crank may be very old. Stop turning and explore a penetrating oil like WD-40 or Liquid Wrench around the base of the crank where it meets the spindle. Let it soak for 30 minutes to an hour, then try again.
If the crank still will not budge, do not force the puller — you risk stripping the threads or breaking the tool. Take the bike to a shop at this point; they have heavier tools and experience with stuck cranks. Forcing it yourself will cost more to repair than a shop visit would.
Frequently Asked Questions
Do I need to remove both cranks at once?
No. You can remove one crank at a time. Most people remove the non-drive side (left) crank first because it is easier. You only need to remove both if you are replacing the bottom bracket or spindle.
What if I do not have a crank puller?
You cannot safely remove the crank without one. Borrowing or renting a puller from a bike shop costs less than replacing a cracked crank. Some shops will remove the crank for you for $10 to $20 if you do not want to buy the tool.
Can I reuse the crank bolt?
Yes, as long as it is not bent or stripped. Clean it before you put it back on. If the bolt spins inside the crank arm without tightening, the threads are stripped and you need a new bolt.
How tight should the crank bolt be when I put it back on?
Tighten it firmly with an Allen wrench, but do not over-tighten — you should feel solid resistance, not a grinding feeling. Most crank bolts are tightened to 35 to 50 Newton-meters if you have a torque wrench, but hand-tight with a wrench is usually correct for home repair.
What is the difference between a crank puller for the left and right side?
The right-side crank puller has a different thread size because the right spindle is wider. Always check which side you are removing before you buy or borrow a puller. Using the wrong puller will not work and may damage the crank arm.