Crank Removal and Installation - Three Piece Crankset (Square Spindle, ISIS, Octalink)

Park Tool
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2 Video Views·Nov 14, 2022
Hello, Calvin Jones here with Park Tool Company.
In this video, we're going to walk through the process of crank removal and installation
for three-piece cranks.
If you're not sure what type of crank system you have, watch this other video and you'll
be guided to the proper removal and installation process.
Otherwise, thanks for joining us and let's begin.
First, before we get into the process, let's give you an overview and a look at what goes
on inside.
We've cut away part of the arm so you can see inside, so we can follow the action.
We take the bolt and remove it counterclockwise.
It's going to come fully out.
What we can see here is that the arm is fitted over the spindle.
Now even though the bolt is out completely, if we grab the arm, it's still not coming
off.
It's still held tight to the spindle.
What's required is a crank remover.
The crank remover has a threaded coupler that goes into the threads of the arm.
It's fully engaged and then the spindle driver is going to come in, contact this outer edge
of the spindle.
We can see what's going to happen if we continue to turn the spindle driver.
It's going to take the arm and pull it away from the spindle.
Pushing against the spindle end, pulling with the arm, continuing until it comes fully off.
The tool is going to be removed from this arm and the process is reversed on the other
side.
Arms going back on are fairly simple.
The crank bolt is going to go in place and it's going to act as the press to push that
arm back onto the spindle.
Here we are engaging and shoving the arm over the spindle.
That is what holds our cranks to the bike.
Now we've seen that, we're going to need a wrench that's going to remove the crank bolt
or nut, a crank remover to extract the arm from the spindle.
We're going to want lubrication and a rag for cleanup and a torque wrench is highly
recommended for the high torques that we see in the three-piece cranks.
Crank arms are removed in order to replace them.
They're either worn out, damaged, or maybe you're upgrading.
You may want to service or replace the bottom bracket and bearings between the arms.
It's also easier to do a thorough cleaning when the crank arms are off the bike.
Step one is always to remove the crank bolt, but sometimes there's a dust cap that's in
the way.
This one has a simple pressed in dust cap, a straight bladed screwdriver pops out the
dust cap and there is the crank bolt under it.
Sometimes it will be a threaded dust cap.
In this case we take a pin spanner, loosen the dust cap, turn it, and underneath the
dust cap is the bolt.
However, there are also self-extracting crank systems.
Here, do not remove this ring, it is not a dust cap.
The self-extracting systems are explained in more detail in another video.
Now let's walk through the full process.
Let's begin with this crank arm by removing the crank arm bolt.
As always, when we work we should consider our body position and our hand and wrench
position.
This is good mechanical advantage.
If I happen to have gone here, that's very poor mechanical advantage.
I could always spin things around and find different ways to hold.
Now I'm ready to loosen counterclockwise.
The bolt comes out and we should always look inside in case a washer was left behind.
Pull this washer out, it must come out before any crank extractor goes in.
The bolt that we've removed is going to let you determine the style of tool that's going
to remove the crank.
The smaller eight millimeter bolts, about the size of a pencil, use the small driver
foot of the CCP-22 or the small foot on the CW-P7 to safely push against the end of the
spindle.
The larger bolts of the Octolinker Isis drive use the larger foot of the CCP-44 or the
large foot option on the CW-P7 to safely push against the spindle of their system.
This was the bolt that we removed from the bike.
Let's get the tool and get to work.
In our case, we want to back up the driver fairly even with the threaded coupler.
Now we are going to install and screw in the threaded coupler, making sure it's not cross-threaded
in the crank arm as we do so.
Screw it down by hand all the way.
It's also good to get a little extra pressure there to make sure we have full thread engagement
of the threaded coupler.
For the nut style spindles, the crank is held on with the nut.
Notice the spindle protrudes past the flat in the crank.
Make sure the spindle driver is well backed up into the threaded coupler so that you get
full thread engagement of the coupler into the crank.
We're now ready to turn the spindle driver down, downward until we feel it contact the
end of the spindle.
Here again, think about your good mechanical advantage, move the wrenches you need and
your hands until it feels more comfortable and begin pressing.
Little bits at a time are fine.
We are locking the crank off the spindle.
Keep going, it's eventually going to get easier and easier.
And now, almost ready, it is coming off by hand and we will repeat the process on the other side.
Installation should begin with surface preparation.
Anti-seize or grease should always be applied to the threads of the bolt.
This helps it pull up fully tight.
Greasing the spindle surface is also an option, especially if you're in an area of corrosion and rust.
What keeps cranks from not creaking, however, is tension from the bolt.
When installing the arm, check the fitting on the spindle that it is correctly clocked
to the fitting on the arm.
Slide the arm in place and now thread in the bolt.
Correct tension is very important for the three-piece crank.
Manufacturers' recommendations go from 30 Newton meters to 45 Newton meters, a very wide range.
This is why a torque wrench is always appropriate.
Consider your mechanical advantage and begin working the bolt all the way in.
The wrench has clicked, we're now at full torque for this brand.
This crank is fully installed.
If you're using a hand wrench, you're going to have to use what's called perceived torque,
or the amount of effort you're putting on that wrench.
Here I am holding the wrench about 10 inches from the bolt.
This is a 350 inch pound recommended torque.
That is about 35 pounds of effort on this wrench, so I am giving it a good healthy push to be fully tight.
Thread preparation is repeated on the opposite side.
The arm is placed 180 degrees from the first arm installed.
The crank arm bolt is installed.
This side will be pulled.
Equal torque to the first side.
And those are the basic procedures for removing and installing the three-piece crank.
For more information, visit the repair help section of ParkTool.com.
Thank you for joining us.
