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 - its still held tight to the spindle.
What's required is a crank remover.
A 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 are cracks 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 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 happened to have gone here, that's very poor mechanical advantage.
I can 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 8mm bolts - about the size of a pencil use the small driver foot of the CCP-22
or the small foot on the CWP-7 to safely push against the end of the spindle.
The larger bolts of the Octalink or ISIS Drive use the larger foot of the CCP-44
or the large foot option on the CWP-7 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 a 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 downward until we feel it contact the end of the spindle.
Here again, think about your good mechanical advantage - move the wrench as you need
and your hands until feels more comfortable and begin pressing.
Little bits at a time are fine - we are walking 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-sieze or grease should always be applied to the threads of the bolt. This helps that pull up fully tight.
Greasing the spindle service is also an option especially if you're in an area of corrosion and rust.
What keeps cranks from 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 ranch 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.