Removing stuck crank arm

[Ludo]

Well, I wanted to take the crankset out to give everything a good clean after the morning ride and and the drive crank arm that is supposed to be removable is stuck on solid.
I backed the bolt head some and give him a few wack with rubber mallet, it’s no budging one bit, any less destructive method I can use?
The cariste was removed 2-3 weeks ago, with no issue, not sure what created that situation

[Wet Noodle]

Depends on the type of crank. Let me consult my crystal ball ...
(Don't whack it, if you have no idea what you're doing.)

Do you really remove your cranks every few weeks just to clean your bike?

[Ludo]

Not usually but I wanted to remove it because last time I greased the preload screw and that was a big mistake as it catching a lot of dirt  so I wanted to take it of to clean it.
Last time I took it off to change chainring

All that being said, the 2-3 previous removal went without any issues, but not this time

[jonathanf2]

Well, I wanted to take the crankset out to give everything a good clean after the morning ride and and the drive crank arm that is supposed to be removable is stuck on solid.
I backed the bolt head some and give him a few wack with rubber mallet, it’s no budging one bit, any less destructive method I can use?
The cariste was removed 2-3 weeks ago, with no issue, not sure what created that situation

Is it a newer crankset for a PF or threaded bottom bracket? I would presume it'd easily come off. Did you lightly grease the axle before installation? Is it totally stuck or were you able to wedge it through the BB, but it own't move from the inside?

[Ludo]

The arm on drive side is supposed to slide if of spindle easy, it did so on previous removal. This time I had torqued the set screw at the max recommended to try and fight a creaking sound, seems that it locked the arm on the spindle

Thinking of using a pulley puller but I need to find a bold to put in spindle to push against or maybe the bolt with the 8mm bit on it and push against that

[jonathanf2]

The arm on drive side is supposed to slide if of spindle easy, it did so on previous removal. This time I had torqued the set screw at the max recommended to try and fight a creaking sound, seems that it locked the arm on the spindle

Thinking of using a pulley puller but I need to find a bold to put in spindle to push against or maybe the bolt with the 8mm bit on it and push against that

Is it the dub-style crankset that screws in from the drive side or the Shimano style crankset that uses 2 pinch bolts on the non-drive side? Pictures would help.

FYI - if it's the 2 pinch bolt style crankset, I toss the cheap stock screws and go immediately with titanium screws and grease the f**k out of them so I can remove them easily down the road. I only use Shimano premium grease nowadays, though there's a good AliEx equivalent now available.

[Ludo]

It’s on the drive side, below link to the crankset for reference:
https://a.aliexpress.com/_msMDT64

I don’t understand how it got stuck so bad.

[jonathanf2]

It’s on the drive side, below link to the crankset for reference:
https://a.aliexpress.com/_msMDT64

I don’t understand how it got stuck so bad.

So the screw doesn't even turn? You might need to use some penetrating oil, let it sit for 24 hours and use a wrench with a longer handle to give you a bit more leverage. The only thing I could think of is that you didn't screw it in properly the last time and the threads are messed up.

[Ludo]

Screw in middle of spindle is remove but crank arm is not budging one bit
At this point nothing is holding the crank arm on spindle but the friction between the two

[Wet Noodle]

Judging from the picture, this is a self-extracting design. In this case, if the crank doesn't come loose, you should not be able to spin the crank bolt freely (counter clockwise) - unless

• the crank bolt or spindle thread is (partially) stripped,
• the crank bolt is broken or
• the extractor cap is not fully seated.

And then, it could also be faulty design (e.g. not enough thread engagement for proper (repeated) extraction or something).

[Ludo]

You are exactly right on the design.
The stem is so stuck on spindle that when I backed out the bolt, it pushed the extractor cap out of the threads. Then I was able to back the bolt out, the true and in spindle are intact, boot threads in and out with no issue whatsoever.
It’s really just the crank arm is stuck solid on the spindle…

[Wet Noodle]

Ah, so the extractor thread is toast, now I get it. Couldn't you just pull the spindle out of the bb anyway (with the ds arm stuck, that is, like a 2-piece crankset)?

As for loosening the stuck arm, if you really have to, use penetrating oil, as was already mentioned, and then give it some time, maybe warm it up with a heat gun and/or give it a cautious(!) spin around the block (or on a trainer ... or just rock lightly on the pedals in 3/9 o'clock position alternatingly).

[Ludo]

On the non drive side there is a big “do not unscrew” on the spindle/crank arm side so I didn’t try.
For the penetrating oil I haven’t done that, I could give it a go but there was plenty of grease in there to start with.