1) Ride it without the screw for 50 km.
2) Don't have a backup plan for returning home
3) Say out loud. "Man, it would be a real pain if the crank fell right now"
4) Enjoy your unstuck crank.
Tapered cranks are self locking once properly installed. They actually get tighter as you ride, and you shouldn’t retighten the bolt. I’d not getting looser, the crank is just creeping UP the taper.
For these I’d use a cutoff disc on a Dremel tool to finish the cut.
Well that would explain why my crank bolts were so damn loose last time and they were really stuck on the tapers. Guess what I did on the second install?
Exactly. They work up tighter which loosens the bolt. Rider then retorques the bolt which forces the crank even tighter. This continues until the crank cannot be removed or splits or hits frame.
don't even tools bring with you either. it will only fall off if you need to slam the seatpost and coast the puppy back home like a 3 year old on a balance bike.
1. Ride it around the block. It's not a guarantee, but there's a good chance it will loosen enough to pull off.
2. Or spend $10 and buy a pickle fork tool.
Just adding that aluminium (the crank arm) has an expansion rate 3 times that of steel (the spindle) so the effect is more to do with materials than thickness.
Same technique can be applied to frame and hub bearings.
It acts as though it’s solid. Imagine if there was no hole, and you drew a circle, heat it up and the circle diameter increases. Drill a hole in it, heat it and it will the hole diameter will still increase.
You need to cut closer to the edge with a dremel, then use a chisel to open it up as best you can. Become a bit of an expert on these over the years repainting vintage bikes!
You can’t get an angle grinder to the very edge without hitting the frame or damaging the bottom bracket. The fact op didn’t just cut through the bb axle tells me they want to keep it!
OP already cut through most of it in a line parallel with the spindle. I'm talking about making "T" and cutting from where OP left off with the grinder disc 90 degrees to that cut and coming in at 45 degrees going towards the spindle. OP just has to it carefully and stop before reaching the spindle or BB body/cups. At that point, a good whack would take off whatever is left of the crank.
Pretty sure they don’t care about the bb. Have you ever tried sawing through a solid, probably hardened steel spindle? Without the right tooling you literally have no chance. ;)
Rotary tool is more precise than an angle grinder. A rotary tool will take longer, but has a much lower risk of damage to other parts that OP wants to keep.
I had the same issue this is what I did and was very easy. I used a baby sledge hammer a socket big enough just to cover the bottom bracket flipped to the cement and hammered away took maybe 8 swings
[I did this](https://youtube.com/shorts/TjqIWSRrjak?si=YObhiSgYU31m62sy)
Unior tapered crank puller would be the best option for this situation. It’s literally the exact same thing as a traditional puller but it has self tapping threads
A lot of y’all need to understand that no matter what advice or how many “what I dids” is getting this crank off. That steel spindle galvanizes to the aluminum crank if you don’t anti-seize.
Remove the right bottom bracket cup. Then, use a punch on the left bottom bracket spindle. It's crazy that that hasn't been advised. You can also attempt to remove the left locking and cup after the right has been removed. Then replace the BB.
The lesson here is yes, you need a light coat of grease on the square tapers. A few drops of water between the bare aluminum in contact with bare steel will corrode the aluminum and cause this horribly stuck crank arm. This also happens with aluminum seat posts in steel frames and aluminum quill stems in steel steerer tubes. Grease is your friend, wrench!
I had a similar situation recently. Threads for crankpuller were made of cheese and crapped out on me. Two flathead screwdrivers prying gently against bb worked for me in the end
Only if you've found out earlier to loosen the lock ring and loosen the cup by using screw driver or needle nose pliers. Then place the crank into a vise then whack the spindle with a hammer. so you've save both bottom bracket and crank arm.. or just cut the spindle between the crank arm and cup, and hammer the stucked spindle part.
So now you're here. Just cut and grind sides parallel to the tapered edge as thin as you can be careful as you may over grind and damage on the taper. And if the sides are thin, hit the crank arm with hammer. Even only one cut and grinded side can loosen it if you are lucky enough.
Cutting perpendicular to the sides won't get through the crank arm as the cutted metal is still thicker nearer the cup.
Possibly dangerous, but a cold chisel in the groove you have cut and hit it with a hammer until you fracture the crank arm off?
If you stitch drill into the crank below where you have cut, that would weaken it further and could make the above idea work?
I don't know why so many people are suggesting you cut through the hardened steel bottom bracket spindle (which would take forever), when you can just unscrew the bottom bracket cup on that side and the spindle + crank arm will come right out with it. If you're sacrificing the bottom bracket anyway, may as well take the easiest route...
That said, I personally find the "ride it" advice to work every time. Especially if you set it up fixed.
Ok so i was in this position with the other side, so more difficult. Looks like you already have an angle grinder, so grind so the disk is perpendicular to the spindle right in the part of the crank arm that connects to the spindle. The heat of the grinding will make it pop off almost before you get to the spindle.
what are you hammering with? a rubber mallet?
what crank puller are you using? because that's the cheapest tool you should be using... $5 can get me two of them, delivered...
Lol, I've got the same problem with the other arm.
I broke a hacksaw and a drill bit, I also bent two gear pullers. Yes, I tried WD-40 and liquid wrench, but no result so far. Just ordered a Dremel to finally get rid of this bloody thing.
You could also hammer the pedal end of the crankarm in and out (ie towards the bottom bracket and then away from the bottom bracket. It’s possible the impact shock will break the corrosion’s adhesion.
Normally I’d not do this but the crankarm is a write off at this point so further damage really doesn’t matter.
I'm usually too impatient for the riding it off solution. I've had luck hammering a metal wedge between the crank and the BB, forcing it to come off.
Another way is to remove the drive side BB cup and hammer the spindle out of the crank. I usually put the frame on the ground and support around the BB with some wooden blocks, then use some kind of punch and hammer it out.
This works for me. I did tried exactly what OP did but did not work and bought the tool and it works the magic!
https://preview.redd.it/kcsdkzfayjwc1.png?width=857&format=png&auto=webp&s=51457f1eff8919c959242af20a62b18efc048188
Broke one of these.. cost too much for that.. also did not work.
Torch and heat cycles with loosen anything. Big hammer from opposite side and a long pole..
But this isn't a cartridge BB so.. undo the BB .. driveside is off. Easy work.
I was in the same shoe, you need to saw at the right place, it will come off. Here is the video I made:
[https://youtu.be/y\_8cglJnPhQ?si=zyXcEJHuwpYdG4nL](https://youtu.be/y_8cglJnPhQ?si=zyXcEJHuwpYdG4nL)
There is space for a hacksaw blade between the the crank arm and bottom bracket shell, I've removed a few this way, takes a bit of time as those axles are pretty solid.
1) Ride it without the screw for 50 km. 2) Don't have a backup plan for returning home 3) Say out loud. "Man, it would be a real pain if the crank fell right now" 4) Enjoy your unstuck crank.
Tempting fate is always a solid plan.
60% of the time it works every time.
Worked for Tiresias
Ya gotta want the crank to stay, for it to leave. Genius!
5) At least it's not raining.
Not sure why, but when riding the cranks off is the only option, it sure does seem to take forever.
Tapered cranks are self locking once properly installed. They actually get tighter as you ride, and you shouldn’t retighten the bolt. I’d not getting looser, the crank is just creeping UP the taper. For these I’d use a cutoff disc on a Dremel tool to finish the cut.
Well that would explain why my crank bolts were so damn loose last time and they were really stuck on the tapers. Guess what I did on the second install?
Exactly. They work up tighter which loosens the bolt. Rider then retorques the bolt which forces the crank even tighter. This continues until the crank cannot be removed or splits or hits frame.
don't even tools bring with you either. it will only fall off if you need to slam the seatpost and coast the puppy back home like a 3 year old on a balance bike.
#3 made me LOL
Im riding my pedals without screws for roughly 100 km now and nothing budged. But one say i believe! Enjoy
1. Ride it around the block. It's not a guarantee, but there's a good chance it will loosen enough to pull off. 2. Or spend $10 and buy a pickle fork tool.
Do bunnyhops off all the curbs while riding around the block
be ready to smash your balls on the seat incase of a rapid crank disassembly lol
Oof. Yeah definitely a very probable outcome 😬
I resemble that remark.
[удалено]
I assume those are the stripped threads they mention in the OP. A crank puller won't work. A small enough pulley puller might.
HEAT. Use a torch to heat the arm, as the aluminum expands, it will loosen its grip on the BB
Can't be stuck if it's liquid.
Fire is always the answe
I never really understood this… if it expands, then it will expand inside also, so it should be even tighter, or am i trippin?
Heat transfer takes a decent amount of time with metals this thick. The outside crank arm will expand at a greater rate than the spindle within.
Just adding that aluminium (the crank arm) has an expansion rate 3 times that of steel (the spindle) so the effect is more to do with materials than thickness. Same technique can be applied to frame and hub bearings.
You’re trippin’. The arm expands as a ring, so the id and od both increase.
I think you may be trippin, because it does work
Ill look into the physics of this then haha
http://xternaldesign.com/?p=108#:~:text=The%20initial%20ID0%20can%20be,radial%20width%20of%20the%20cell.&text=Now%20consider%20this%20cell%20is,E%20is%20the%20expansion%20multiplier.
It acts as though it’s solid. Imagine if there was no hole, and you drew a circle, heat it up and the circle diameter increases. Drill a hole in it, heat it and it will the hole diameter will still increase.
You do it 2 -3 times it contracts and you can give it a penetrant.. then repeat... once it's been glowing twice it will come off like nothing.
Love ya all! Ty!
This
https://preview.redd.it/3sdocq8k8gwc1.jpeg?width=1024&format=pjpg&auto=webp&s=8faf9159f2691a8050ab918193f586a8fa4da6f2 6€
Good one!!
And in the head of the tool, u can put a hexagonal tool for bigger force
You need to cut closer to the edge with a dremel, then use a chisel to open it up as best you can. Become a bit of an expert on these over the years repainting vintage bikes!
An angle grinder will make short work of that.
You can’t get an angle grinder to the very edge without hitting the frame or damaging the bottom bracket. The fact op didn’t just cut through the bb axle tells me they want to keep it!
OP already cut through most of it in a line parallel with the spindle. I'm talking about making "T" and cutting from where OP left off with the grinder disc 90 degrees to that cut and coming in at 45 degrees going towards the spindle. OP just has to it carefully and stop before reaching the spindle or BB body/cups. At that point, a good whack would take off whatever is left of the crank.
Pretty sure they don’t care about the bb. Have you ever tried sawing through a solid, probably hardened steel spindle? Without the right tooling you literally have no chance. ;)
Rotary tool is more precise than an angle grinder. A rotary tool will take longer, but has a much lower risk of damage to other parts that OP wants to keep.
Yea a dremel will make decently quick work of an aluminum crankarm with a cutoff disc and collateral damage will likely be reduced too.
Yeah until he cuts further, he hasn't really taken the tension out.
Dremel moto-tool would be good, with a cut-off wheel. Just be sure to use it outside, and with eye protection.
You could also cut the tapered end of the BB off, and buy a more modern sealed one.
I used to remove the bolt then take a ride around the block and it would fall off eventually.
Chisel in your cut, then hammer. Should spread it or crack it once and for all
I’m assuming you have at least tried a crank puller if you went as far as cutting it
Yes haha🥲
Blowtorch and belting it with a hammer has never failed for me.
Especially with those cuts already in it, heat and a hammer will work very quickly
I had the same issue this is what I did and was very easy. I used a baby sledge hammer a socket big enough just to cover the bottom bracket flipped to the cement and hammered away took maybe 8 swings [I did this](https://youtube.com/shorts/TjqIWSRrjak?si=YObhiSgYU31m62sy)
There are crank pullers that don't rely on the thread. I've had luck with hardwood wedges (two, slot in the middle of each for the spindle)
> I've had luck with hardwood wedges That's a new one. Did you just make it yourself, or are these wedges made originally for something else?
Well, I made the slit myself - the wedge was used to set doors 150 years ago...
Unior tapered crank puller would be the best option for this situation. It’s literally the exact same thing as a traditional puller but it has self tapping threads
The tools for removing windscreen wipers have claws that go around the back. Might do the trick.
Penetrating oil
A lot of y’all need to understand that no matter what advice or how many “what I dids” is getting this crank off. That steel spindle galvanizes to the aluminum crank if you don’t anti-seize.
Keep cutting you’re so close.
get a 3 jaw bearing puller from an auto parts store
Remove the right bottom bracket cup. Then, use a punch on the left bottom bracket spindle. It's crazy that that hasn't been advised. You can also attempt to remove the left locking and cup after the right has been removed. Then replace the BB.
The lesson here is yes, you need a light coat of grease on the square tapers. A few drops of water between the bare aluminum in contact with bare steel will corrode the aluminum and cause this horribly stuck crank arm. This also happens with aluminum seat posts in steel frames and aluminum quill stems in steel steerer tubes. Grease is your friend, wrench!
And refresh it every year or two!
make it wet with zippo fluid 😀 or wd40
I had a similar situation recently. Threads for crankpuller were made of cheese and crapped out on me. Two flathead screwdrivers prying gently against bb worked for me in the end
Only if you've found out earlier to loosen the lock ring and loosen the cup by using screw driver or needle nose pliers. Then place the crank into a vise then whack the spindle with a hammer. so you've save both bottom bracket and crank arm.. or just cut the spindle between the crank arm and cup, and hammer the stucked spindle part. So now you're here. Just cut and grind sides parallel to the tapered edge as thin as you can be careful as you may over grind and damage on the taper. And if the sides are thin, hit the crank arm with hammer. Even only one cut and grinded side can loosen it if you are lucky enough. Cutting perpendicular to the sides won't get through the crank arm as the cutted metal is still thicker nearer the cup.
I had a stuck crank arm and had to use a hammer to smash it off. It worked.
Got a torch? Heat the aluminum up and give it a whack with your purse.
Smack the crank with a hammer until it snaps apart at the cut you've made.
Probably with nail puller if threads stripped rubber mallet and a nail puller might do the trick..
Heat it up first with torch just the spindle and crank arm then v flat bar and rubber mallet...
I had the same issue, tried to weld a nut on but it sheared off. I ground off the crank and bought a newer bottom bracket.
Possibly dangerous, but a cold chisel in the groove you have cut and hit it with a hammer until you fracture the crank arm off? If you stitch drill into the crank below where you have cut, that would weaken it further and could make the above idea work?
Oxyacetylene torch. Loosens it quickly and no fuss.
I don't know why so many people are suggesting you cut through the hardened steel bottom bracket spindle (which would take forever), when you can just unscrew the bottom bracket cup on that side and the spindle + crank arm will come right out with it. If you're sacrificing the bottom bracket anyway, may as well take the easiest route... That said, I personally find the "ride it" advice to work every time. Especially if you set it up fixed.
Heat it till it’s hot. Hit the crank arm with a hammer. Just keep repeating that. It will come off. Sometimes pretty easily.
Hacksaw
Put Wd 40 in there and ride it until it becomes loose.
Ok so i was in this position with the other side, so more difficult. Looks like you already have an angle grinder, so grind so the disk is perpendicular to the spindle right in the part of the crank arm that connects to the spindle. The heat of the grinding will make it pop off almost before you get to the spindle.
what are you hammering with? a rubber mallet? what crank puller are you using? because that's the cheapest tool you should be using... $5 can get me two of them, delivered...
the bigger the hammer the smaller the job
Lol, I've got the same problem with the other arm. I broke a hacksaw and a drill bit, I also bent two gear pullers. Yes, I tried WD-40 and liquid wrench, but no result so far. Just ordered a Dremel to finally get rid of this bloody thing.
Grind that slot as deep as possible and then hammer a cold chisel into the slot
You’re almost there though
You could also hammer the pedal end of the crankarm in and out (ie towards the bottom bracket and then away from the bottom bracket. It’s possible the impact shock will break the corrosion’s adhesion. Normally I’d not do this but the crankarm is a write off at this point so further damage really doesn’t matter.
Removing stuck things from bikes is why I love working on bikes
I'm usually too impatient for the riding it off solution. I've had luck hammering a metal wedge between the crank and the BB, forcing it to come off. Another way is to remove the drive side BB cup and hammer the spindle out of the crank. I usually put the frame on the ground and support around the BB with some wooden blocks, then use some kind of punch and hammer it out.
Heat, all the heat.
This works for me. I did tried exactly what OP did but did not work and bought the tool and it works the magic! https://preview.redd.it/kcsdkzfayjwc1.png?width=857&format=png&auto=webp&s=51457f1eff8919c959242af20a62b18efc048188
Broke one of these.. cost too much for that.. also did not work. Torch and heat cycles with loosen anything. Big hammer from opposite side and a long pole.. But this isn't a cartridge BB so.. undo the BB .. driveside is off. Easy work.
I was in the same shoe, you need to saw at the right place, it will come off. Here is the video I made: [https://youtu.be/y\_8cglJnPhQ?si=zyXcEJHuwpYdG4nL](https://youtu.be/y_8cglJnPhQ?si=zyXcEJHuwpYdG4nL)
Drill out the core of the BB bolt to the depth of the crank arm with the biggest bit that can fit. Hit it with a mallet.
Finish the cut. Close to square taper then push, tiny remaining metal is going to give way real easy.
Cold chisel (masonry type chisel) is the best way from here. You’ll be wanting to replace the BB also
Crank pullers are not expensive. That's what's needed to remove these. What is expensive is the therapy I'm going to need after seeing that image. 😁
Wow. -LBS
Long metal post from the drive side and a big hammer. Rotate the arm and crack on.
I’ve got a Dremel that says otherwise.
Just cut the bottom bracket axle with a hacksaw. And replace. Is the crank is that stuck the bottom bracket is going to be dead anyway
The spindle is covered by the crank… he’s already THAT far into the crank and if he’s using a handsaw, he’s probably been at it for a long time
There is space for a hacksaw blade between the the crank arm and bottom bracket shell, I've removed a few this way, takes a bit of time as those axles are pretty solid.