Mickey2

The crank is loose on my old Raleigh 3 speed, and the bike has separate crank arms fitted with cotters. I don't know if bikes come with this setup anymore, but it seems to work well. I have searched the web, watched youtube tutorials and tried the suggestions I've found. I've found two ways about it; one is hitting the cotter pin with a mallet or hammer suporting the crank harm with a piece of wood. The other is using a silid vise with a nut on one side of the cotter to make room for it too loosen when presser is applied to the side where the nut was. I just bought a heavy vise, and using a hard metal bit from a wrench set I know the pressure on the pin has to be considerable, yet is it stuck not sign of movement. Any clever tricks that can be used in combination with the vice? Any ideas how to go about it? This turned out much more difficult than I thought.

arex

Try soaking it overnight with your favorite penetrating oil. Be sure that the fat end of the pin has room to go somewhere when you're pressing it out; that is, make sure you're not inadvertently holding it in place with something. Don't stand down-range of the pin..sometimes they go dangerously ballistic when they come loose. I almost shot my dog with one a few nights ago.

Velocivixen

Yes for penetrating oil overnight.

Mickey2

Thanks, that was quick. I will go for the penetrating oil right away and let it work over night. I'll let you know how it turns out ;- )

3speedslow

Sometimes when the pin wobbles it means the pin has got a relief worn into it. When that happens it is very important to line the crank hole with the flat side of the crank spindle. You want a clear path for the pin to be driven out and not be caught on the side of the spindle.

might not have explained it too well.

noglider 

Occasionally, cotters give a huge amount of trouble. Once, I used a drill and went as straight through the middle as I was able. Then I went back to pounding, and it still wasn't easy.

Chances are, you'll be luckier than that.

Mickey2

Thanks for further tips both of you. I don't need to be the winner in a contest of the most difficult cotter pin, I don't have that many tools to sort things out lol. I hope the oil works, or I may have to seek out a stronger guy than me to turn the vise.

oddjob2

PB Blaster or WD40 Rust Formula (yellow and black can) work best of the widely available stuff.

dddd

I've had well-stuck, original cotters that started to bend when I applied my home-made cotter press (hammering would be even much more likely to bend the threaded stud of the cotter!). At that point I left the vice clamped on and applied a heating/cooling cycle to the bigend of the crank, then tightened the press very slightly tighter. Another heating cycle and another application of torque to the press and the cotter finally yielded, in still-usable condition.
Heating to the point where oil residues begin smoking is nowhere near harmful to steel or to chrome plating, but avoid torching any thin-profiled push-pin of the cotter press, which might get near red-hot very quickly and thus softened/damaged.

It's important to keep the original cotters in usable condition, since replacements tend to be of sub-standard quality, very soft, and with undersized threaded stud as compared to the originals.

After re-installing the cotter, I alternate hammer blows with nut tightening. When the nut finally won't tighten any further, the cotter is fully home, and less able to notch the cotter from the spindle rotating within the crankarm under hard pedaling.
Use a sturdy punch of some sort to avoid having the head of the hammer ding your crankset. A long, heavy bolt as used in roadway/guardrail construction makes a good punch to hit with the hammer, but any thick steel rod should work.

Prowler 

I'm now a believer in the advice to leave the nut in place when removing cotters. I only back the nut off 1/2 turn then apply the cotter press. The nut protects the threads and reduces the chance of seriously bending the pin. I quit hammering the pins out - one win and lots of losses. A hot air gun does help too. Push the pin/nut until it moves a whisker. Loosen the nut another 1/2 turn and push again. Repeat as needed

I've saved the spindle from a skanky old mtn bike pedal and use that for a punch. Very hard steel that has a nice fat striking end and a small 'business end'. And when it's too worn I'll recycle that and get another.

John E

Great thread. I really like the advice about leaving the nut on the threaded stud, a practice I have applied in numerous applications in addition to cotter-pushing. I used to replace cottered cranks with aluminum as a matter of course, but I need to keep the highly collectible Capo Sieger as original as possible, cotters and all.

dailycommute

This is one job I have found the park press at the LBS to be the best tool and well worth finding shop with one. I have hammered, viced, and homemade press attempted and without doubt the park cotter press tool is the best bet. Out in a minute or so and the pin is not damaged at all.

Homebrew01

Bigger hammer.
I leave the nut on, unscrew just a bit and whack. The nut spreads the load over the threads.

AlexCyclistRoch

My bike co-op has an old-school cotter puller. If you are lucky, some shop near you still has one, but the reality is that cottered BB bikes haven't been sold in 40 years! I still own 1, BTW.

rsterman

I PB blasted it for two consecutive days......let it sit for one more day just for good measure.......then set the bike up so the bb was not stressed when I started blasting. I used a punch with a concave end. Three good cracks with a hammer on the punch and the cotter came shooting out like a bullet. Check the utube video from RJ-the bike guy who has a good video on how to make a cotter press. It will save you $60, and it works well......good luck..... Cotter are big PIA!

Prowler 

I agree - a press is the way to go. I've been very impressed with the BikeSmith cotter press. Very solid design that can get close to the chain ring on the DS. I've heard that some tool designs have trouble with some of the DS cranks. I also like that you can hold the tool body securely with one BFWrench while you torque the press screw with the other wrench. Confidence inspiring.

noglider 

Good video, ugly hands.

Mickey2

Great video. So far I'm having no luck. I have it in vice with a bit from a wrench set on the side the pin comes out. I am using all my force to turn the vice tighter. It's a large vice, and cumbersome to use, but I though it would give the same punch on the pin. The clever little tools seem like they have more force directly on the pin though, since they get the threaded part pushed down before the pin loosens. For the moment I'm letting the pin stand in the vice, giving it a go no and then.

bmthom.gis

I just overhauled a cottered bike...and had very little trouble myself. I used a small block of wood on the initial hammer blows to distribute the load, then used a nail punch. Had to use some Kroil on one of them, but after a few minutes of sitting, the next good hammer blow knocked out. I didn't even bother trying to reuse the pins. Seems like an almost futile effort, to me. I also didn't need to file the new ones. They slipped in quite easy. After 11 miles this morning, they are still nice and tight.

francophile 

Nothing beats having the proper tool, and nothing good ever came out of hammering a cotter IMHO. Proper tool is # 07 at the top of this sheet and it'll pop a cotter out in less than 2 seconds with minimal effort. Historic VAR Bicycle Tools Catalogue 7 Cotter Pin Press, 371 Vise, 63 Hammer, 354 TA Pin Driver

Best tool purchase I've ever made, sniped it off eBay, didn't pay the 3-digit sum they normally command. Suddenly I love working on cottered bikes.

But, what I will say is this: Even using a VAR 07, if it's not quite adjusted right or someone took to the cotter already, you're bound to bend the damn thing. There are some creative ways around that. Prior to getting the VAR tool, I had a good amount of luck using the "Bench vise" method: https://www.youtube.com/watch?v=OQg89p6gcjk

dddd

The punch/hammer I referred to, that prompted your reply, was only for getting the cotter back in, alternating hammer blows with nut tightening until the cotter is heavily seated. I always use my press for removal, since so often cotters will not respond to hammering out without bending unless serious heat is also applied.

If leaving the nut on and hammering the cotter out, you'll need back off the nut enough to allow for some length compression (both elastic and yielding) along the cotter's length, or may actually shear the threads.

There is a lot of variability in terms of how stuck that a cotter will be, so you never know to what level of removal sophistication and effort will be required. I always expect the worst, and always try mightily to save the original cotters.

Bikerider007

I agree with others. If you haven't already destroyed the thread, screw the nut down until it's flush, put a rag or something behind so it does not beat crank up once it lets loose. Then give it a good whack, or two or three.

Anytime I add penetrating oil I use a rubber mallet and tap the crank, tube or whatever to try and get oil to vibrate down into.


Use a flat nut, not the rounded head type. It leaves room behind it.

Salubrious

Its always a matter of the right tool for the right job.

In the case of cotter pins, that's a cotter pin press. It used for both removal and installation. Even really stubborn pins can be removed- heat and penetrating oil might have to be used if corrosion is present. Leave the nut on the part and just budge the pin slightly. The nut is used to prevent deformation of the threads. Then the nut is removed so the press can be used to push the pin the rest of the way.

The press must be used for installation! The nut is only there to retain the pin once its pressed into place. Do not attempt to draw the pin in place using solely the nut- you might get away with that, but you might also find the crank to loosen up later, or you may find that the pin strips its threads.

It really is a good idea to retain the original pins if you can!! They are filed to the correct dimensions and are likely a lot harder than the cheap ones often found in bike shops today. And there is no reason they can't be reused unless incorrect technique was employed during removal.

Once you've had and lived with a cotter pin press you will find that the system has/had a lot to offer- anyone dealing with crank creak in newer (JIS) systems knows what I'm talking about. You simply don't get that if you use a cotter press. It is all suddenly quite easy- the only pain the rear might be fitting new pins to an existing system. There are several diameters in use and they often have to be filed even if they are the right size pin which can take some time! This is why its so nice to retain the original parts.

Michael Angelo 

I've had one cotter give me fits. So I made a monster Cotter press, NEVER had one stick again. I do have a Park Tools press too. I use the park too first, if it won't budge the big one comes out....

Mickey2

It's an old post but I'm still on this problem. What a lovely set of tools, I want them all. Can your monster press be made to order under special circumstances Michael Angelo?

I still struggle with this. I handed the bike in to my local bike store, and the guy there drilled them out. He said it was a lot of work. The crank is now cleaned, greased and tightened nicely, but the pedal arms are loose for some reason. I don't know what kind of mismatch-bike I bought, but it's like the left and right pedal arms takes different size cotter pin. Is that possible? They look identical and I never would have wondered if they came from two different sets.

Salubrius, I have to take out the cotter pins and file them? I missed your post there, and now I have to have them out again? This is horrid work!