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Cotter pin removal... Too easy!

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Cotter pin removal... Too easy!

Old 05-05-21, 11:53 AM
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Cotter pin removal... Too easy!


Well that was easy. Removed cotter pins, serviced bottom bracket, and reassembled in 1/2 hour!

A couple years ago I bought a 70's Super Course, and the seller included a copy of "Anybodys Bike Book". I leafed thru it. Fun illustrations but nothing stuck out to me but this little device for cotter pin removal. A 9 1/2" inch piece of 1/2" pipe and a floor flange. Brilliant! Today I visited my local hardware store and purchased the two pieces and 1/2 an hour later my Gitane has a freshly serviced BB. Love it.

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Old 05-05-21, 12:07 PM
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Originally Posted by big chainring View Post

Well that was easy. Removed cotter pins, serviced bottom bracket, and reassembled in 1/2 hour!

A couple years ago I bought a 70's Super Course, and the seller included a copy of "Anybodys Bike Book". I leafed thru it. Fun illustrations but nothing stuck out to me but this little device for cotter pin removal. A 9 1/2" inch piece of 1/2" pipe and a floor flange. Brilliant! Today I visited my local hardware store and purchased the two pieces and 1/2 an hour later my Gitane has a freshly serviced BB. Love it.

​​​​
That is SIMPLY brilliant.
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Old 05-05-21, 12:35 PM
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How do you grease the bearings without the time tested secret additives of chain lube contaminated knuckle blood and sweat profusely dripping from one's forehead?
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Old 05-05-21, 12:46 PM
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That's awesome....I bought the press and now feel like i wasted money.
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Old 05-05-21, 02:36 PM
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Originally Posted by big chainring View Post

Well that was easy. Removed cotter pins, serviced bottom bracket, and reassembled in 1/2 hour!

A couple years ago I bought a 70's Super Course, and the seller included a copy of "Anybodys Bike Book". I leafed thru it. Fun illustrations but nothing stuck out to me but this little device for cotter pin removal. A 9 1/2" inch piece of 1/2" pipe and a floor flange. Brilliant! Today I visited my local hardware store and purchased the two pieces and 1/2 an hour later my Gitane has a freshly serviced BB. Love it.

​​​​
I’ve not removed any but expect to in the future. Can you explain what you did to remove the pin?
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Old 05-05-21, 02:37 PM
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Originally Posted by jamesdak View Post
That's awesome....I bought the press and now feel like i wasted money.
The press is a far better system for both installing and extracting cotter pins.
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Old 05-05-21, 03:20 PM
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Originally Posted by Big Block View Post
The press is a far better system for both installing and extracting cotter pins.
I agree.

No drama, pin comes out, most times if nobody beat it with a hammer before you you can use it again.

And you can't blame the marks in the cups on the difficulty of removing the pin.
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Old 05-05-21, 03:39 PM
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Originally Posted by Big Block View Post
The press is a far better system for both installing and extracting cotter pins.
Amen. I really need to take a video the next time I swap cotters on something with my VAR press, since there appear to be no vides on the internet. Once you understand how to adjust it correctly you can pop in our out a cotter in under 10 seconds, including a 5 second break to sip your beer.

I know, it's hard to get one for under $100. I know, there are other tools out there, including a variety of C-clamp presses, custom tools, BFH and pipe or wood, but none are as fast and effective.
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Old 05-05-21, 03:47 PM
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PS - I don't want to come off like I'm downplaying OP's tool. It's super clever. I wish I'd thought of it, and it goes to show the wealth of knowledge in old magazines and catalogs. Some of the old cycling catalogs have killer info on how to, for example, break down and reassemble a Campy NR rear mech, I think I posted that one here a few years ago when I found it.

The only thing that bothers me about using the back pipe method or a socket, or any other method using a hollow steel receiver to hammer in/out is after enough whacks with a BFH, you'll leave a ring print on both sides of your crank arm. It's definitely not something I'd do with some of the higher-end alloy cottered crank arms.

For replacing cotters on pre-80s cottered steel cranks, it's cheaply effective though. Make sure you swing straight and true!!
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Old 05-05-21, 04:10 PM
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So the pipe stanchion approach is to support your BB, right? You still need to whack the cotter with a hammer. That's where all kinds of bad things could happen (I say from experience).
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Old 05-05-21, 04:22 PM
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Originally Posted by nlerner View Post
So the pipe stanchion approach is to support your BB, right? You still need to whack the cotter with a hammer. That's where all kinds of bad things could happen (I say from experience).
Agreed. All it allows is for someone to beat a cotter to a mushroom. while putting less stress on the BB bearings. That's it.

Otherwise, the results here aren't likely to be any better than beating it in a work stand if the cotter is well and truly tight.

-Kurt
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Old 05-05-21, 04:29 PM
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Originally Posted by cudak888 View Post
Agreed. All it allows is for someone to beat a cotter to a mushroom. while putting less stress on the BB bearings. That's it.

Otherwise, the results here aren't likely to be any better than beating it in a work stand if the cotter is well and truly tight.

-Kurt
That's what I thought. But i should also say that I've destroyed plenty of cotters using the BIkeSmith tool. It provides plenty of force, so much so that the threaded part of a reluctant cotter will mushroom before any movement happens.
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Old 05-05-21, 04:51 PM
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Originally Posted by BikingViking793 View Post
I’ve not removed any but expect to in the future. Can you explain what you did to remove the pin?
I removed nut and washer from cotter pins. Sprayed WD-40 into and around crank hole/cotter. Threaded nut back on so nut is level with top of threads. Put support under crank arm as in picture. Drive side took one hit with hammer and it came loose. Other side took three hits to break it free. I noted direction of cotters and kept them oriented same way for each crank arm. The cotters were pretty much in perfect condition, and the tapers fit tightly against BB spindle. I am guessing its the first time they were removed since installed at factory some 50 years ago.
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Old 05-05-21, 05:11 PM
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Originally Posted by big chainring View Post
I am guessing its the first time they were removed since installed at factory some 50 years ago.
That might have a lot to do with why they came out easily; they went in clean, to a clean axle, with the correct tool.
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Old 05-05-21, 05:59 PM
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Originally Posted by oneclick View Post
That might have a lot to do with why they came out easily; they went in clean, to a clean axle, with the correct tool.
On the other hand this bike has seen a lot of weather and use. Wheels were heavily rusted and numerous flat spots. Frame has quite a bit of rust under the top tube, probably from sitting outside in the rain. The front derailleur cage was so bent I replaced it. And the brake pads were extremely worn. This bike was well used and abused. But yes it was assembled well at the factory...50 years ago.
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Old 05-05-21, 06:15 PM
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It's all those bloody 'one size fits all' soft steel cotters causing most removal issues. Harder steel, a good vice and file if needed and cotters last decades.
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Old 05-05-21, 06:24 PM
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I've been using this pipe stanchion method for ages. I remember buying the pipe at Home Depot. I chose a pipe that was damaged on one end, figuring I'd save the store the cost of one pipe since no one else could make use of it. The cashier asked me what size it was so she could ring it up properly, and I said I didn't know. She asked how I know it's going to work if it's not the right size. I told her I wouldn't be using it as a pipe, but then I immediately regretted saying that. I should have said I was planning to use it as a weapon. Well, maybe it's better I didn't.
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Old 05-05-21, 06:25 PM
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Originally Posted by big chainring View Post
On the other hand this bike has seen a lot of weather and use. Wheels were heavily rusted and numerous flat spots. Frame has quite a bit of rust under the top tube, probably from sitting outside in the rain. The front derailleur cage was so bent I replaced it. And the brake pads were extremely worn. This bike was well used and abused. But yes it was assembled well at the factory...50 years ago.
The exterior doesn't matter - for the pins.

Were they clean when they came out - a single witness line from the axle flat, no galling or corrosion?
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Old 05-05-21, 06:34 PM
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Originally Posted by oneclick View Post
The exterior doesn't matter - for the pins.

Were they clean when they came out - a single witness line from the axle flat, no galling or corrosion?
Very clean.
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Old 05-05-21, 07:05 PM
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There's good cotter pin removal info and 2 good YouTube videos on this thread:

Restoration of a Raleigh Stowaway 1983 - (Advice will be needed!)

I'm finally getting the '73 Raleigh I posted about back on the stand to finish the job I started 2 years ago. The cotter pins look good enough to reuse


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Old 05-05-21, 09:26 PM
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I have used three methods to remove cotter pins:

(1) Banging on the pin with a hammer while it is on a bike stand. This works sometimes, but often not, and you end up doing something drastic like drilling out the pin. As far as I know I didn't destroy any bottom brackets, but I only did it on heavy old steel bikes.

(2) Banging on the pin with a hammer while the pedal is resting on a steel pipe. I think I got this from Sheldon Brown, and I do believe it works much better than banging without a steel pipe. I think the shock must be sharper or something, but the likelihood you will get the pin out without mushrooming seems significantly better.

(3) Bikesmith press/clamp. This works better than banging, but you still destroy a pin sometimes. Cotter pins just aren't very predictable.
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Old 05-06-21, 12:39 AM
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Originally Posted by cudak888 View Post
Agreed. All it allows is for someone to beat a cotter to a mushroom. while putting less stress on the BB bearings. That's it.

Otherwise, the results here aren't likely to be any better than beating it in a work stand if the cotter is well and truly tight.

-Kurt
I disagree. The pipe to the floor is not to protect the bearings, which cannot be harmed by hammering (I've done that experiment!). The pipe is to give you the sharpest or shortest-duration impulse (in the physics sense of the word). Without the pipe, your impulse gets spread out in time, with the peak force attenuated, by passing through the frame, bike stand etc. (or the tires if the bike is sitting on the ground.

I have a Var cotter press, and while it is a prized possession, I generally just reach for my hammer, punch and pipe for the occasional cotter I need to knock in or out. I agree the press is better for most people, who haven't spent as much time swinging a hammer as I have, but for me there's little downside to the hammer, and it's quicker.

I'm pretty sure I've never been defeated by a cotter, and very seldom had any problem at all, like mushrooming the thread. The bike shop I worked at in the early '70s had a half-price overhaul deal in the winter to keep from having to lay off mechanics. And so many bikes were cottered back then, easily the majority, maybe fair to say the vast majority. So we were hammering cotters out and back in multiple times per day on average during overhaul season. If I remember right, we each had our own pipe-with-floor-flange, because sharing one would have slowed us down, it'd be in use all the time.

If I suspect the cotter is in tight and/or corroded in place, I'll apply heat before I even try it. Just a heat gun, no need for the blow torch, though I did use a propane torch before I had a heat gun. Heat works like magic. Not sure why, since all the parts (usually) are steel, all with the same thermal expansion coefficient, but the effect is real. Actually for last few I've done, I went straight to the heat gun without even trying a whack first. Since I'm not trying to make a living at it, I can afford the heat-up time, a couple minutes — pays off in reduced stomach acid.

The other trick is to use a stout punch with a concave end that holds it centered on the cotter. My punch is actually a cottered BB spindle that has dimples on the ends, that just happen to match the curved ends on cotters (most cotters anyway; maybe not all have curved ends). Whatever metal that spindle is made of, it's about perfect, hard but not brittle. Been using that same one since about '72. If I didn't have that, I'd make one, from a 3/8" or larger punch (example), grinding the concave shape into the end with a spherical stone or maybe a carbide burr in the Dremel. Chuck the handle end of the punch in a drill chuck and hold the drill motor in the vise; set it spinning and use the trigger lock to hold it "on" (poor man's lathe). Then you have both hands free to hold the Dremel tool precisely against the business end of the punch. Use a stone or burr with about the same radius as the ends of the cotters, but it doesn't need to be an exact match. There are "cup tip" punches that come with the concave end, but I haven't seen them in a large enough size for bike cotters. Mostly a gunsmith thing, with 1/8" or 3 mm being about the biggest I saw when I looked.

For knocking the pin out (or in), hold the punch with some pliers or vise-grips, because otherwise fear of hitting your hand will cause you to "pull your punches" (pun not intended, I swear!). I like a framing hammer. Not a ball-peen, which doesn't have a flat striking face, so it's more likely to kick your punch out sideways. And a decently large hammer too; mine is 22 ounces. Hold the hammer handle out at the end like a Real Man (I see people choking up sometimes, holding the handle near the head). Experience will teach you how hard to swing the hammer. Sneaking up on it by hitting it more softly at first is acceptable, but I pride myself in whacking the pin out with one swing. Show it who's boss!

Ooh I just remembered when my dad taught me how to knock cotter pins out. Probably about 1969, when I was twelve. He was an engineer at Rocketdyne in the '60s, making moon rockets. We had a stout bench vise at home, and that was his preferred method: open the jaws of the vise just enough to let the cotter slip between them (not clamped), with the crank sitting on top of the vise. It takes a second person to hold the bike in position while you swing the hammer, but it's pretty effective, about as good as the pipe method for increasing the sharpness of the impulse to the pin. Keep that method in your back pocket as it were, in case you ever need to git 'er done and you don't have a pipe, but you do have a vise and a helper/holder.

Mark B
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Old 05-06-21, 02:56 AM
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Originally Posted by bulgie View Post
Heat works like magic. Not sure why, since all the parts (usually) are steel, all with the same thermal expansion coefficient, but the effect is real.
Even though they are (usually) the same material, the temperature is not, and the difference is (again, usually) enough to get them separated. It's not hard to get a delta-T of several hundred degrees over an inch or so of steel.

Of course it helps to keep the flame away from the ends of the pin, but for pins that are corroded at the interface that actually helps. Rust is more of an insulator than steel, by about two orders of magnitude, so with heat the worse it looks the better it works - as long as you heat the hole, not the pin.
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Old 05-06-21, 04:18 AM
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Heat works because the gunge/rust binding the two steels together doesn't expand at the same rate so the bond is broken.
With a vice you can crack the nut a thread, lay the bike up sideways on the vice, place a socket over the other end of the cotter pin that gives clearance and use the jaws of the vice to press the pin out.
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Whacking with a hammer usually wrecks the thread but an M6 metric die straight over the damaged imperial thread renders a result that will give you back a good thread for reusing the same pin albeit with a M6 nut.
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Old 05-06-21, 06:21 AM
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Originally Posted by Johno59 View Post
Heat works because the gunge/rust binding the two steels together doesn't expand at the same rate so the bond is broken.
I thought this might be the case so I did a little net-searching; there are lots of values for thermal expansion rates for various steels, but the only one I found for rust specifically was in a walled-garden publication and all I got to see was a tale with the actual values not the units.

For what it's worth the numeric values for rust were about half of the numbers elsewhere for steel, but without units what can you tell. If so that's even better for the use of heat, the hole gets MORE bigger than the rust.
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