How to remove stuck cotter pins ?

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pete75
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Re: How to remove stuck cotter pins ?

Postby pete75 » 11 May 2015, 4:53pm

Brucey wrote:a length of thick-walled tube under the crank braced against a concrete floor gives (light) hammer blows somewhere to react to. I have found that many small taps with a hammer often count for more than one big blow, but also a straight blow counts for more than anything else; thus it is best if you use a drift of some kind.

cheers


I don't know why anyone bothers to suggest alternatives to this method. It works and uses tools most people already have.

Brucey
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Re: How to remove stuck cotter pins ?

Postby Brucey » 11 May 2015, 5:22pm

pete75 wrote:
Brucey wrote:a length of thick-walled tube under the crank braced against a concrete floor gives (light) hammer blows somewhere to react to. I have found that many small taps with a hammer often count for more than one big blow, but also a straight blow counts for more than anything else; thus it is best if you use a drift of some kind.

cheers


I don't know why anyone bothers to suggest alternatives to this method. It works and uses tools most people already have.


-exactly... and it doesn't trash the BB bearings, either.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

drossall
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Re: How to remove stuck cotter pins ?

Postby drossall » 11 May 2015, 6:26pm

pete75 wrote:I don't know why anyone bothers to suggest alternatives to this method. It works and uses tools most people already have.


Because they don't have a suitable length of tube? The sledgehammer-under-the-crank method normally works very well too, contrary to any impression that I may have given. I've got a sledgehammer, so I tended to use it :D

Brucey
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Re: How to remove stuck cotter pins ?

Postby Brucey » 11 May 2015, 6:33pm

if you have something to act as a spacer (a large nut, or a short length of tube) to go between the sledgehammer head and the crank, you can get a properly straight hit onto the cotter pin, instead of one that is against an offset bolster....

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

drossall
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Re: How to remove stuck cotter pins ?

Postby drossall » 11 May 2015, 6:55pm

Good thought, though somewhat academic, as I no longer have any cottered cranks :D

JohnW
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Re: How to remove stuck cotter pins ?

Postby JohnW » 11 May 2015, 7:30pm

Brucey wrote:I know someone who has that tool. It is quite good but you still need to use the hammer on ones that are well stuck. The tool is also rather pricey. So overall, probably not worth the money I'm afraid.

cheers


Oh yes Brucey - all tools have their limits - often because the parts that they are designed to separate are 'stuck' really fast, whatever 'stuck' means in any situation - remember the freewheel removers with the two lugs that engaged with the freewheel? - before the advent of splined removers? - and how many of us have smoothed off an allen key? - nothing is perfect.

I subsequently encountered your "thick-walled tube" method, but it was too late for me because I'd started using cotterless cranks by the time I was shown it. To be honest, if I'd had a better brain than I have, I'd have thought it out for myself. I never damaged any BB bearings as far as I know, whilst not using what I now know as proper support.
Last edited by JohnW on 11 May 2015, 7:40pm, edited 1 time in total.

Brucey
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Re: How to remove stuck cotter pins ?

Postby Brucey » 11 May 2015, 7:36pm

sure.... but at best that particular tool is a convenience rather than -as some others are- a necessity.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

JohnW
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Re: How to remove stuck cotter pins ?

Postby JohnW » 11 May 2015, 7:42pm

Brucey wrote:sure.... but at best that particular tool is a convenience rather than -as some others are- a necessity.

cheers


That's also true.

greyingbeard
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Re: How to remove stuck cotter pins ?

Postby greyingbeard » 11 May 2015, 10:01pm

pete75 wrote:
Brucey wrote:a length of thick-walled tube under the crank braced against a concrete floor gives (light) hammer blows somewhere to react to. I have found that many small taps with a hammer often count for more than one big blow, but also a straight blow counts for more than anything else; thus it is best if you use a drift of some kind.

cheers


I don't know why anyone bothers to suggest alternatives to this method. It works and uses tools most people already have.


It worked for me. I got one of them free, the other still stuck. Mr W.D. Forty helped a bit too.
My supporting tube was an axle stand.
Seems a bit awkward to use a socket and a big vice, theres a lot of bike getting in the way.

Next task stuck seatpost. This may need machining out. Very very accurately, the steel frame tubes are so thin. Hopefully my hero WD will come to the rescue once again

pete75
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Re: How to remove stuck cotter pins ?

Postby pete75 » 11 May 2015, 10:50pm

greyingbeard wrote:
pete75 wrote:
Brucey wrote:a length of thick-walled tube under the crank braced against a concrete floor gives (light) hammer blows somewhere to react to. I have found that many small taps with a hammer often count for more than one big blow, but also a straight blow counts for more than anything else; thus it is best if you use a drift of some kind.

cheers


I don't know why anyone bothers to suggest alternatives to this method. It works and uses tools most people already have.


It worked for me. I got one of them free, the other still stuck. Mr W.D. Forty helped a bit too.
My supporting tube was an axle stand.
Seems a bit awkward to use a socket and a big vice, theres a lot of bike getting in the way.

Next task stuck seatpost. This may need machining out. Very very accurately, the steel frame tubes are so thin. Hopefully my hero WD will come to the rescue once again


If it's an aluminium seat pin the caustic soda method works well. I know this from experience. It doesn't damage paint or the steel frame. Use some blue tack to seal the seat tube at the bottom bracket and fill the tube with a strong solution of caustic. You may need to change it once or twice.

steve browne
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Re: How to remove stuck cotter pins ?

Postby steve browne » 12 May 2015, 8:15am

I have had one of the BikeSmith cotter pin presses for a few years now. I help as a volunteer cycle mechanic at our local bike recycling charity and all the bikes with cotter pins come my way. It has failed on one occasion to extract a cotter pin and that is because the pin had already been bent by previous attempts at extraction with a hammer. This one required drilling out in order to save the chainset.
Their bottom bracket cup tool is brilliant and a pleasure to use.

greyingbeard
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Re: How to remove stuck cotter pins ?

Postby greyingbeard » 12 May 2015, 11:16am

Is a fillet brazed frame - closed BB shell (a threaded pipe). Could be tricky to achieve this.
Will caustic soda damage the brass/bronze ?

pete75
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Re: How to remove stuck cotter pins ?

Postby pete75 » 12 May 2015, 11:35am

It may react with brass but not in the dramatic way it does with aluminium.

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531colin
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Re: How to remove stuck cotter pins ?

Postby 531colin » 12 May 2015, 6:34pm

greyingbeard wrote:Is a fillet brazed frame - closed BB shell (a threaded pipe). Could be tricky to achieve this.
Will caustic soda damage the brass/bronze ?


You can drill a hole in the seatpost somewhere and inject the caustic that way....the seatpost is scrap anyway, and Blue tac will plug the hole?

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531colin
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Re: How to remove stuck cotter pins ?

Postby 531colin » 12 May 2015, 6:36pm

Back on topic, I always used a length of scaffold tube to support the crank when removing cotter pins. Not exactly hard to come by, or cut to length.