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
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  • 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.


Related Links

Discuss this topic in the Crank Forums

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!



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

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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.
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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 >>

11/15 Sram Red Non-Drive Bolt Problem

So I attempted to remove this crankset, but the bolt that attaches the non-drive crank arm to the spindle did not budge. Instead, two other bolts that seem to work in conjunction with the one I wanted to loosen have come out.

Anybody have a suggestion on my next course of action?

[Image: 10730777_998114350206082_664889122962744...e=54EB66D2]


10/24 Crank arm

I recently bought a cheap fixie bike from Walmart. The crank arms seem to be too long and I'm finding it to be a problem whenever I want to turn. Although I'm not doing much turning when I do I can't without having my crank arm hit the front wheel or my feet hitting the wheel. Please help... Read more >>

10/22 1982? Peugeot (pending) Crank bearing repair

First Re-Lube since 1980's.... Square Taper Peugeot Branded 3 piece crank.
Plan is to Clean, replace bearings, and Re-Lube. Have tool for pulling arms.

My question...

If I find caged bearings, what is the conscientious.....????

Put in Loose bearings for more contact, (probably 11 because I won't find the original caged bearings....)

OR Try and find caged bearings... ?

Other than more bearings==better contact... Any suggestions?

I do have access to loose Grade 25 bearings at the local bike shop...
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10/21 Replacement Crankset

Hello all!

So like many others I have had the unfortunate experience of the thread on my right crank arm stripped after only a month of usage (gutting I know!). However, I am not silly enough to try and take the easy and definitely unsafe option of using a helicoil kit (as surely that would just make the hole larger than it already is and therefore the pedal even more so unstable?).

Therefore I am in the market for a new replacement crankset that I can take to my LBS to get replaced.

I currently have the Felt F95 bike, size = 58cm.

10/21 Slight crank/chainring wobble need some advice

I have a race face Chester crankset with a race face narrow/wide chainring
and it looks like the driveside crankarm and chainring have a slight wobble back and forth.

Its only been a month since install and I have so far only used the bike for riding back and forth to work nothing even close to extreme.

Now I'm not totally If it has actually done this since install cuz i diden't really notice it then and also I don't think i paid the much attention to it when i first installed it cuz i was kinda over excited. I got everything all tighted up and gave it a spin e... Read more >>

10/21 Cranks for Haro Backtrail X2

hi everyone...i'm giving a 2004 haro backtrail x2 nyquist to an 8-yr old kid as his first real bmx bike. He's tall enough to ride with the seat almost all the way down, but the stock one-piece cranks on the bike are way to long to ride in that seat configuration. How do I determine the proper aftermarket crank type and size for the backtrail X2 so I can order a new set? Do I need a new sprocket too, or is the old one (remember one-piece crank) reusable with new cranks? And if I need a new sprocket, must it have the same number teeth as old sprocket to work with the existing freewheel hub? ... Read more >>

10/03 How do I remove this crank?

[attachment=5378]Hi all I found this place by google, Im going to sound like an idiot but I hope someone can help me. Im not much of a bike person but I bought this trike to ride with my kids for fun, exercise & family outings. Unfortunately not long after buying (secondhand) I was riding and the right hand pedal came out of the crank, the crank thread is striped. Through googling I have become aware the reason is who ever assembled the bike put the right pedal on the left crank and vice versa.

Bike is from trike-bike.com.au .

[attachm...

09/11 Clank sound after 10 miles

[attachment=5352]I hope someone has run across this before. I have a Giant mountain bike and I have been using it on the paved trail a lot lately. Recently, I began hear a clanking sound after I ride about 10 miles. Sounds like when a pedal hits a kickstand that isn't all the way up. I can't duplicate it on a bike stand. It doesn't start until 10 miles and after 15 miles, I get an added rubber squeaking sound on top of the clank. The noise happens in the same pedal position every time and particularly when I'm pedaling hard and hardly at all if I pedal lightly. I had the derailleurs and s... Read more >>

09/06 Threaded Left Crank Arm (Pedal thread)

I shipped my Dawes Super Galaxy home and have just had an unfortunate experience of not being able to re-attach my left Shimano M324 pedal.

It looks threaded, but I still have hopes as I think it's only the top couple of rings on the inside.


From what I can tell the pedal thread is fine.

I know there are tools out there to fix a thread. I'm hoping that mine is not so bad that I need a new crank set. Can anyone offer any advice?



The Gala...

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