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
Categories
Discuss this topic in the Crank Forums
Crank Rookie
posted 1 year agoI picked up a low end Cannondale Hybrid (1999 H300) to get back into cycling and to learn a few things about bike mechanics. The bike is great for fitness, but I've started to tear it apart and refit with some inexpensive upgrades, as that is the stuff I love to do. My latest project has been to replace the BB (110-68 square taper-JIS) and upgrade he crank. The original spec listed the crankset...
Read morePedal Washers ?
posted 2 years agoHey Guys, Was just wandering... Some of my bikes came with pedal washers and some do not have pedal washers. What I'm talking about is the washer that fits between the crank and where the pedal threads on. Are they needed? or not? Thanks...
Read moreCrankset repair.
posted 2 years agoHi guys! My bike has been damaged. The crankset is curved now. From the information I have found it is Suntour XCC 48/38/28 (http://www.gtbicycles.com/usa_en/2013/bikes/urban/sport/transeo-4-0). The problem is that I don't know the bottom bracket size and anything else. So do you have any ideas what crankset can replace my old one and please tell me what instruments do I need to replace it (r...
Read moreReplacing crankset - chainline and bottom bracket question
posted 2 years agoHi all, I have a bike that I'm doing up as a project and I need to replace the bottom bracket (square taper). Since the front chainring (single, 46 teeth) is pretty badly worn I was going to take the opportunity and replace that as well. But what to get as replacement? At the back I've got a 6-speed freewheel with a chain line of 38 mm. The bike is nothing special, it's more for fun and the lear...
Read moreNew crankset, screw unscrews
posted 3 years agoI have bought a new (shimano) crankset (I believe it is called a diamond crank) for my MTB. I've installed it myself (which is probably the problem :-p), rode with it a couple hundred KMs and all of a sudden the non drive side crank becomes wobbly and after a couple of meters the screw that holds it unscrews and falls off. I tried to tighten it really hard, I applied loctite at the end of the scre...
Read moreStiff Crank, no sound as if the bearings are gone
posted 3 years agoIronhorse Maverick 3.0, what could be wrong. It was just fine yesterday went out for a ride today not even out of the parking lot crank became stiff still rotates both ways no sound like it's the bearings gone. Is it just dry and needs to be greased or something...
Read moreThis has broken loose. What is missing?
posted 3 years agoThis 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 moreStripped Crankarm
posted 4 years agoA 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 moreCrank bearings
posted 4 years agoI 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 moreTrying to remove pedals....wtf
posted 4 years agoOk 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? ...
Read moreiClic 2 Clicking In Trouble
posted 4 years agoMy 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 moreClicking noise coming from crankset
posted 4 years agoIve 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 moreCrank removal tool
posted 4 years agoHello, 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 moreCrank arms
posted 4 years agoHello 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 th...
Read moreCrank set replacement
posted 4 years agoI 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 ...
Read more