9. How to Replace Cotterless Crank Arms

Crank removal and installation procedure on a square-spindle, sealed bottom bracket.

IMPORTANT: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.
How to Replace Cotterless Crank Arms
DVD Vol. 1 DVD Volume 1
This video is available on DVD

VIDEO UPDATES

  • 02:08 - The crank bolts should be torqued to about 35 foot-pounds, or 420 inch-pounds.

This tutorial will demonstrate how to remove and install square-spindled crank arms. I've based this tutorial on cranks attached to a sealed cartridge bottom bracket. I’ll cover the loose-bearing style in a future tutorial.

Tools Required

To remove the bolt, you'll need either an 8mm allen key or 14mm socket wrench. To remove the crank arms, you’ll need a crank puller, a 16mm open-end wrench, and an adjustable wrench. If possible, a torque wrench should also be used for tightening.

Crank Arm Removal

In order to safely remove the right side, you'll have to shift the front derailleur onto the smallest chainring, and then carefully remove the chain and rest it on the bottom bracket, so that it doesn't interfere with the crank arm removal.

Using the crank arm for leverage, loosen and remove the tightening bolt with your allen key or 14mm socket wrench. Be careful not to skin your knuckles on the chainring teeth.

Before using the crank puller, make sure it is fully extended so that the internal driver does not extend past the external threads.

Note: If crank threads are damaged, there are a few solutions at Park Tools.

Carefully thread the external threads of the crank puller clockwise into the crank arm. Avoid cross-threading, which will damage the crank and prevent future removal.

Once the crank puller is fully threaded, place the adjustable wrench on the external flats and turn the internal driver clockwise until it stops. Turn the driver clockwise using a 16mm wrench, until the crank arm pulls free of the spindle. Repeat the same process to remove the left crank arm.

Crank Arm Installation

Before re-installing the cranks wipe both the square spindle and the crank's spindle fitting to make sure there is no dirt or grease on either surface.

Now slide the right crank's spindle fitting onto the spindle. Before installing the bolts, grease under the head and along the threads of both bolts. Thread the bolt all the way into the spindle threads and torque the bolt to about 35 foot-pounds, or 420 inch-pounds.

Set the chain back on the chainring and repeat the same installation procedure on the left side, making sure the crank arm is pointing opposite the right side.

Tags

Related Links

Discuss this topic in the Crank Forums

06/27 This has broken loose. What is missing?

This is a cheap and rusty old bike, but it's one my son has really enjoyed.  I can't figure out what broke off that would make the crank area loose.  If anyone could identify what broke or what part fell off or what the issue could be, I'd be most appreciative.  Thanks!

http://imageshack.com/a/img537/4911/PGpvNj.jpg
http://imageshack.com/a/img537/7691/g7GRKo.jpg... Read more >>

06/06 Stripped Crankarm

A few weeks ago I replaced the broken pedals on my mountain bike with cheap $8 plastic pedals from Wal-Mart. Yesterday I was riding the bike and all of a sudden my pedal fell off. Upon closer inspection, I found the pedal AND the hole where the pedal screws into the crank arm is both stripped. What can I do?... Read more >>

05/17 Crank bearings

I bought a next px6.0 26in mens mountain bike from walmart. The bearings need to be replace and i don't have the crank puller and don't know what the size is for the bearings can any one help me.... Read more >>

05/07 Trying to remove pedals....wtf

Ok so long story short ive been trying to remove a pedal for a while now. Never have been able to. Today i decided to try an idea from a family member....heat the metal, then try to loosen it. And when i did, THIS happened. And I STILL can't get the mofo unscrewed. Any ideas?


[Image: 73i3bm.jpg]

[Image: 11bu25z.jpg]

[Image: 2rcr020.jpg]... Read more >>

04/06 iClic 2 Clicking In Trouble

My iClic 2 pedals don't hold my cleats solidly. Are there any adjustments that can be made to this pedal? I just replaced my cleats and it made no difference. Any suggestions would be appreciated.... Read more >>

02/22 Clicking noise coming from crankset

Ive been getting a clicking noise coming from the crankset on each revolution (doesnt seem to be the pedals).... Should I start by regreasing the chainring bolts? (bike's only 2 summers old).... or should I be going as far as taking apart the crankset and take out the bottom bracket?... Read more >>

02/13 Crank removal tool

Hello,
I have a circa 1988 crankset - Shimano FC-M730.
I cannot find a puller/remover for it (have spent $70 so far).
Can anyone help me out finding the correct remover?
Thanks.... Read more >>

02/12 Crank arms

Hello I've just registered and would like some help.
I have had a knee replacement and now only have 90 degrees of bend
I have a shorter crank and have raised the seat as high as I can but still
find that I need to pedal with my heel to be able to achieve full rotation.
Now I have heard of something like an articulated crank which hinges in the middle
and when in use full power is obtained when the pedal is between 2 o'clock and 5
if that makes sense. I wonder if anyone else has any ideas about this problem

IAN... Read more >>

02/10 Crank set replacement

I bought a mountain bike with a seized suntour free wheel which I changed our for a 7 cluster Shimano. When I went to set up the front deraileur I notice the teeth were badly worn. So I pulled the 3 sprocket crank set off. it is a shimano crank set but has no stamp on it other then a sticker biopace SG for narrow chains only. It is a regular  mens mountain bike. The only markings are shimano and Selkirk on the bike. the big sprocket has 48 teeth. Does anyone know what a common, good inexpensive crankset I could buy on line  to replace this?... Read more >>

01/23 Will this crankset work with this freewheel?

Hello everyone. I'm new to here so what I'm going to ask might be stupid. I'm trying to fix a bike I inherited but I'll need to change wheels and probably crankset as well. If somebody could have a look and let me know if be really grateful. Also the front wheel's hub is 100mm but my fork's 90mm. I read on other forum it should be ok to stretch the fork to fit the hub in. Is that true? Thanks a lot and have a nice day!

Wheels:

26 x 1 3/8 (590 RIM) SINGLE SPEED WHEEL SET COMPLETE FOR TRADITIONAL TOWN BIKE

26 x 1 3/8 (590 x 19) ALLOY RIMS

AL... Read more >>

01/08 Crank removal

A friend wrote me and wants to know what spindle he might have on his Schwinn Recumbent Bike model 223. He wants to replace the crank arm but is not sure whether it is square, isis or? He needs to know which removal tool to buy. Anybody know this or can he visually just look and see? Thanks.
Bud... Read more >>

12/03 Gt pedal size issue. Need help

Get guys, forum and bike repair noob here. I picked up a 1994 gt performer (always wanted one when I was a kid). The pedals are in bad shape and need to be replaced. I've done some research and 1/2 and 9/16 are the common size of pedals based on 1 or 3 piece cranks. I've measured the diamater of the threaded end and it's neither size. Anyone know off the bat whit size runs on my gt? It's bone stock btw.... Read more >>

12/03 Pedal sizing

Get guys, forum and bike repair noob here. I picked up a 1994 gt performer (always wanted one when I was a kid). The pedals are in bad shape and need to be replaced. I've done some research and 1/2 and 9/16 are the common size of pedals based on 1 or 3 piece cranks. I've measured the diamater of the threaded end and it's neither size. Anyone know off the bat whit size runs on my gt? It's bone stock btw.... Read more >>

12/03 Im new. Need help.

I have an entry level MB Diamondback Sorrento from 2011 and I need a new crank set and FD. Currently, my bike has a MTB 24/32/42t and my BB width is not specified. I'm looking for a replacement crank set without breaking the bank. If I have to get a new chain or BB then so be it. But I'm trying to avoid a front end rebuild.

For reference, my back cassette is a 7-speed 14-28.

Can I change chainring sizes without getting a new BB? And how do I know it will be compatible with my frame and rear cassette? Insight would be much appreciated.... Read more >>

11/16 Gitane Mixte Crank bearing repair

Starting in on Wife's 1970-ish bike...
Removed cotter-ed crank after oiling pins for a few days.
Brief look at insides.. RUST! 7 Bearing 'assembly' coated with rust... closed that area for now.

At present, soaking crank and gear parts in solvent to remove light rust from chrome... Will examine bottom end cups and cones later today...

This bike will remain steel BB.

Saving grace for both bikes is they were in a garage for entire life....... Read more >>

New Thread
How to Replace Cotterless Crank Arms
Repair Guide / Help Forums

Free Email Updates: