How to Replace Cotterless Crank Arms
Crank removal and installation procedure on a square-spindle, sealed bottom bracket.
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.
Related Links
- Park Tool: Bicycle Torque Specifications
- Park Tool: Crank Installation and Removal
- Sheldon Brown: Cotterless Cranks
- Bicycle Torque Specifications
Recommended Tools
- Shimano TL-FC10 Crank Extractor
- Park Tool Wrench Combo Set
- Park Tool PAW-12 Adjustable Wrench
- Park Tool WTK-2 Essential Tool Kit
- Park Tool SK-3 Starter Mechanic Tool Kit
- Park Tool PK-3 Professional Tool Kit
Categories
Discuss this topic in the Bicycle Repairs and Mechanics Forum
Shimano RevoShift upgrade
Latest post 2 weeks agoHello. I bought a 2003 Raleigh SC40 recently. It is in very good shape but does show its age in areas. One is the 3x8 Shimano RevoShift twist shifters. They work just fine but are cosmetically challenged. The right rear shifter plastic cover has broken. I am inclined to replace both with new Shimano twist shifters. Hoping for suggestions, recommendations and cautions. Thanks for the help. ...
Read moreSpecialized bicycle post issue
Latest post 2 weeks agoHi folks - this is my first post! The seat post on my year old Roll 3.0 is doing something annoying. It has a bit of play around the shiny collar just above the post clamp (see photo). I was told there is a plastic sheathing inside. Can this be fixed or is the seat post all one assembly? IMG_3153.jpeg (Size: 58.61 KB / Downloads: 700) ...
Read moreSram Transmission derailleur possibly dead?
Latest post 2 weeks agoI have a bike in with an unresponsive transmission derailleur. Customer said it was hit with a stick that went into the spokes. There's no obvious damage other than wear and tear scuff marks. The battery is good and tested with the dropper. The shifter is good and working. The button on the derailleur does nothing. Single click, double clicking and holding the button. no response, no servo buzz,...
Read morePhilodo H8 5000W
Latest post 2 weeks agoHave a out 300 miles on a Philodo H8 5000W. A couple of times, after turning it on, it flashed "12" for a few seconds. Anyone have a clue?...
Read moreAxle keeps slipping on applying force/climbing hills..
Latest post 3 weeks agoMy friend is having this issue where the axle keeps slipping in the rear dropouts and hit the chain stay on the non-drive side. IMG-20260418-WA0021.jpg (Size: 82.12 KB / Downloads: 86) This usually happens when a lot of force (climbing on a high gear or standing to sprint) is applied. It’s worse when the bicycle is loaded up with camping gear on the rear rack. Things tried th...
Read moresuspicious broken part after service--is this legit?
Latest post 1 month agoHey all, I'd love some feedback on a repair issue. I just got the brakes bled and the first ride after was fine. But after one week of sitting idle, I took it out and the rear brake was suddenly making a horrible loud screeching noise when applied. Took it back to the shop and the mechanic showed how the two halves of the brake were not perfectly aligned and holding firm and there was oil leakage....
Read morePros & Cons of presta valve vs schrader valves
Latest post 2 months agoA question I've wanted to ask for a while now. From a personal point of view, what have you found to be the positives and negatives of these two valves? What would your preference be?...
Read more70's=80's Free Spirit Blaze MTN
Latest post 2 months ago70's-80's Free Spirit Blaze MTN 2.JPG (Size: 21.86 KB / Downloads: 13) 3.JPG (Size: 33.89 KB / Downloads: 14) DSCN3722.JPG (Size: 32.65 KB / Downloads: 14) 4.JPG (Size: 56.63 KB / Downloads: 14) I need a front index shift lever or the matched set. Falcon derailleur, 10 speed or whatever is compatible. 7.3mm is the closet spacing measure...
Read moreFront Disc screeching/vibration .. help please :-)
Latest post 2 months agoFront Disc brake(Shimano) makes dreadful noise/vibration just at the ‘bite’ point where it stop the wheel (final 2 or 3 cms of rotation on the rotor ! Only started a month ago No luck in sorting it ! .. have had pads, rotor and caliper all replaced and it makes very little difference (all are clean, aligned and functioning as they should) Absolutely no problem on the rear. Don’t know wh...
Read more2nd hand rad rover repair help needed
Latest post 2 months agoSo I bought this second hand rad rover five power bike it worked for the whole day and the end of the day I thought it died on me but it hasn't been able to start back up please contact me if you think you could help I've done some research and I have no idea what I'm doing I just need some help somebody knows what they're doing to guide me with this please I spent all my money on this I don't hav...
Read moreNeed help with Drivetrain Update
Latest post 4 months agoHello everyone, I'm an older lifelong cyclist that recently had my beloved old yeti mountain bike stolen, and to try and fill that void, I picked up a 2015 Specialized Crosstrail (I'm riding more paved and gravel trails these days, my full-on mountain bike days are over!). The bike was in very good physical condition, apparently very lightly used. I was unable to ride before purchase, but it looke...
Read moreVelowave Ranger break change question
Latest post 4 months agoHello! I tried to change my Velowave ranger e-bike breaks and the lever would not have traction. I researched and learned I needed to bleed the breaks, I tried the top method with the cup with a break bleeding kit. Still had the same issue, I tried to use the syringe at the caliper but the hole was too small for any of the included adapters. Is it just trapped air in the calipers/line that is ca...
Read moreEye to Eye Shock Lengths
Latest post 4 months agoWill my conversion work? I have an old 2014 Giant Trance 1. It is a small frame. It is just a backup bike. It is still fun to ride and works well when a friend is or family member is visiting and bikeless. I hate sending things to the land fill or not being able to keep them repaired and running. I already replaced the fork a couple of years ago. I already found some parts and converted to a ...
Read moreShimano law suit
Latest post 4 months agoRemember the Shimano law suit? Fortunately I had the"good model series" Thousands of riders trusted these components without a second thought. Now, the story has taken a serious turn. Shimano has agreed to pay an $11.5 million penalty after US regulators found the company failed to report a major defect in its 11 speed road cranksets on time. According to the CPSC, Shimano had received thou...
Read moreQuestion regarding rear hub replacement for possible out of production bike?
Latest post 5 months agoHi there, I have a question in regards to either finding a replacement hub for my rear Mountain Bike or just replacing the whole wheel entirely. However when I went to a local bicycle shop (in China, that is so there are language barriers to keep in mind), upon inspection they claimed that the bicycle was too old to accept the replacement of their modern parts, which I honestly find hard to believ...
Read more



