Extended crank set keeps slowly unscrewing no matter what I do, causing wobble and looseness in the pedals.

Deliveryfoot

New Member
Joined
Sep 3, 2020
Messages
24
New update:



It's hard to see, but it seems the bearings are digging into the shaft itself. Creating a pit and valley. I use the lowest gear possible, but i do a lot of hard and heavy pedaling from a dead stop, especially uphill. I bought a spare crank set expecting the worst and luckily it paid off. So i replaced nearly everything. The cups inside seemed perfectly fine.

I took the advice of park tools here and pulled the bearings from the cage and shoved them in with grease like in the video

And as i began testing new parts, put it through a bit of a torture test, though no different from if i had to pedal on an incline at a dead stop and it immediately began "loosening". And my understanding is such, the shaft is cheap chinesium and is pitting under the pressure of the bearings from the strenuous pedaling.

Please, if anyone can recommend a good website where i can buy a new high quality extended crank set in canada, please let me know!
 
Last edited:

Chainlube

Well-Known Member
Joined
Jan 5, 2020
Messages
4,849
New update:



It's hard to see, but it seems the bearings are digging into the shaft itself. Creating a pit and valley. I use the lowest gear possible, but i do a lot of hard and heavy pedaling from a dead stop, especially uphill. I bought a spare crank set expecting the worst and luckily it paid off. So i replaced nearly everything. The cups inside seemed perfectly fine.

I took the advice of park tools here and pulled the bearings from the cage and shoved them in with grease like in the video

And as i began testing new parts, put it through a bit of a torture test, though no different from if i had to pedal on an incline at a dead stop and it immediately began "loosening". And my understanding is such, the shaft is cheap chinesium and is pitting under the pressure of the bearings from the strenuous pedaling.

Please, if anyone can recommend a good website where i can buy a new high quality extended crank set in canada, please let me know!
Caged bearings are a different size than loose bearings, loose balls need to be bigger.
 

Karl Snarl

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Joined
Sep 20, 2019
Messages
3,397


Jul 21 2012 UPDATE!:

Took apart the cup. Turns out the issue was crushed bearings cartridge on the drive side. I dont know the name, but its a light piece of metal that holds the bearings in a circle.

I'm only here to point this out before i forget to entirely. I'll try and let others know if its because i put the bearings in backwards or not. Or if its just because i tightened too much.



2nd update:



It's hard to see, but it seems the bearings are digging into the shaft itself. Creating a pit and valley. I use the lowest gear possible, but i do a lot of hard and heavy pedaling from a dead stop, especially uphill. I bought a spare crank set expecting the worst and luckily it paid off. So i replaced nearly everything. The cups inside seemed perfectly fine.

I took the advice of park tools here and pulled the bearings from the cage and shoved them in with grease like in the video

And as i began testing new parts, put it through a bit of a torture test, though no different from if i had to pedal on an inclide at a dead stop and it immediately began "loosening". And my understanding is such, the shaft is cheap chinesium and is pitting under the pressure of the bearings from the strenuous pedaling.

Please, if anyone can recommend a good website where i can buy a new high quality extended crank set in canada, please let me know!





This is my latest attempt to get it to stop. I put small metal rod between the 3rd screw inlet and even used marine JB weld to possibly seize it all up. Cleared the threads of grease and soaked in blue lock tite and cured for 24 hours.

After 5 minutes of pedaling, the crank went from firm to ever so slightly wobbly. I am certain it will continuously unwind like it did before. If not, the wire will jam it up and leave me with some annoying amount of wobble.

The threads here are both "right-tight". Even the smaller "lock nut" i am sure that's not right, but it was the only way it would thread on.
Idk if you solved the prob, but if you haven't, or for the future, here's my dolla fifty. I take out the caged bearings, and use crowded ball. It take a few more, and some slickness sometimes finding the right ball size. Usually its just a size up though if it needs a bigger ball. Then I pack them with a tacky high temp grease. It holds all the balls in when putting it back together too. I am however going to be slowly converting to sealed bearings per advice of another here on the forum. They are far superior to the caged and crowded ball design and a lot cleaner to replace.
 
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