$16 Cotter Press
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The castings do appear to be inconsistent w/regard to brittleness/strength. Mine's been working for a few years now without a hitch. It hasn't failed to remove any of a few dozen cotters for me. 


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#102
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If you see one of these at a swap...buy it.

#103
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By now, I have a couple of cotter presses including the HF one that I made seven years ago.
One thing that continues to be true is that often enough, the precious, hardened original cotter(s) will not budge from pressing alone, before bending the cotter. I use a short piece of rubber tubing stuffed into the end of the main driver bolt to prevent the pin/sleeve from falling out while in the tool drawer.
Factory-installed French cotters are often the tightest, but I saw the cotters on my original Super Course start to yield in bending before I stopped tightening the press and ran to get the torch. This shows how much force is involved as the fine-threaded stems on these English cotters are thicker than most.
This is when I leave the tightened tool in place, and heat the end of the crank for several minutes with a propane torch.
I heat until there is plenty of smoke issuing from the assembly when the torch is pulled away, then I try tightening the press a bit more.
Of course this has to be done outside, unless one works under a laboratory exhaust hood.
When a cotter fails to budge on the first try, again I leave the tool tightened in place, and now let the assembly cool down for a good half-hour, then tighten a bit further and, as is usually necessary, heat-cycle it again.
They do eventually break free using heat cycling, and then there will be no difficult search-and-wait in obtaining properly-sized, hardened cotters. The cotter almost always breaks free when the crank is in it's heated state, vs. when it has cooled, and they often push out upon the first serious heating.
In the more-distant past, I drilled them to get them out, but at some point I began using heat and hammer blows to get them out damage-free.
It is rather difficult to damage the bearings using the hammer method without also first damaging the cotter from too much hammering force using too little or no heat. I at least never visibly damaged any bb bearings that way.
I have seen too many cotters ruined from hasty removal attempts that skipped the application of heat. I admit though that I often have not first given the cotters a full 24 hours of soaking with a serious penetrant.
I've also seen many cotters that turned out to have been insufficiently tightened, especially the softer ones that are available today. Cotters should be secured by alternating between impact and tightening of the nut until the nut doesn't want to turn any more.
My Harbor Freight press has survived over a dozen uses by now, but from the start I did add a reinforcing sleeve to the pin and then reversed the pin so that the concave head end contacts the cotter.
I posted a photo of my version many years ago, and have since ground the casting down here and there as needed for use on different cranks.
Here again is the older photo:
One thing that continues to be true is that often enough, the precious, hardened original cotter(s) will not budge from pressing alone, before bending the cotter. I use a short piece of rubber tubing stuffed into the end of the main driver bolt to prevent the pin/sleeve from falling out while in the tool drawer.
Factory-installed French cotters are often the tightest, but I saw the cotters on my original Super Course start to yield in bending before I stopped tightening the press and ran to get the torch. This shows how much force is involved as the fine-threaded stems on these English cotters are thicker than most.
This is when I leave the tightened tool in place, and heat the end of the crank for several minutes with a propane torch.
I heat until there is plenty of smoke issuing from the assembly when the torch is pulled away, then I try tightening the press a bit more.
Of course this has to be done outside, unless one works under a laboratory exhaust hood.
When a cotter fails to budge on the first try, again I leave the tool tightened in place, and now let the assembly cool down for a good half-hour, then tighten a bit further and, as is usually necessary, heat-cycle it again.
They do eventually break free using heat cycling, and then there will be no difficult search-and-wait in obtaining properly-sized, hardened cotters. The cotter almost always breaks free when the crank is in it's heated state, vs. when it has cooled, and they often push out upon the first serious heating.
In the more-distant past, I drilled them to get them out, but at some point I began using heat and hammer blows to get them out damage-free.
It is rather difficult to damage the bearings using the hammer method without also first damaging the cotter from too much hammering force using too little or no heat. I at least never visibly damaged any bb bearings that way.
I have seen too many cotters ruined from hasty removal attempts that skipped the application of heat. I admit though that I often have not first given the cotters a full 24 hours of soaking with a serious penetrant.
I've also seen many cotters that turned out to have been insufficiently tightened, especially the softer ones that are available today. Cotters should be secured by alternating between impact and tightening of the nut until the nut doesn't want to turn any more.
My Harbor Freight press has survived over a dozen uses by now, but from the start I did add a reinforcing sleeve to the pin and then reversed the pin so that the concave head end contacts the cotter.
I posted a photo of my version many years ago, and have since ground the casting down here and there as needed for use on different cranks.
Here again is the older photo:

Last edited by dddd; 12-26-19 at 11:31 PM.
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#104
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Worked great, thanks for the tip
I used a half inch hand drill and a vice to drill out the hold. It was slow going but worked. I drill press would work much better.
Worked great, thanks for the tip.
Worked great, thanks for the tip.
Last edited by engineerrock; 05-11-20 at 08:40 PM. Reason: typo
#105
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Start with a Harbor Freight Chain Breaker.
Take it all apart and get your drill press out.
Drill out the parts shown:

Toss the bits that have the X next to them into your junk drawer.
Put it back together as a cotter press. Don't forget to grease the threads:

You will have 2 pushers that go in from the inner side. One is a spare in case the thin part breaks. I doubt it. It's got to be stronger than the cotter threaded part and because of the way it is built should not twist inside the tool.
Place tool over cotter/crank and tighten outer bolt until the pusher touches down:

Press out cotter using inner bolt:

Take it all apart and get your drill press out.
Drill out the parts shown:

Toss the bits that have the X next to them into your junk drawer.
Put it back together as a cotter press. Don't forget to grease the threads:

You will have 2 pushers that go in from the inner side. One is a spare in case the thin part breaks. I doubt it. It's got to be stronger than the cotter threaded part and because of the way it is built should not twist inside the tool.
Place tool over cotter/crank and tighten outer bolt until the pusher touches down:

Press out cotter using inner bolt:

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#106
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#107
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#108
Newbie
Here we are in 2022. I just received this chain tool from Amazon a few days ago and just did the conversion as detailed above today.
Two possible differences:
1) There was a steel insert where you need to drill it out to 31/64". I was able to drive it out with a big hammer and punch. It was pressed in with a spline.
2) The tool I got only came with one pin vs the 2 shown on the Harbor Freight tool.
https://www.amazon.ca/Breaker-Splitt...s%2C129&sr=8-1
Otherwise I'm sure it was exactly the same tool from the same company. $22 Canadian from amazon.ca, plus shipping. (I didn't need anything else). Total $31.10 CAD.
Conversion done, and I used the tool already to push out the cotter on my Raleigh DL-1 Tourist Sir Wayes A. Tonne.
I have also ordered 2 pairs of Raleigh cut cotters from Mark Stonich Bikesmith.
When I reinstall I'll be pushing the cotters home with the press and then retightening after a bit.
Thank you so much to the OP for the design of this tool!! Much appreciated.
Two possible differences:
1) There was a steel insert where you need to drill it out to 31/64". I was able to drive it out with a big hammer and punch. It was pressed in with a spline.
2) The tool I got only came with one pin vs the 2 shown on the Harbor Freight tool.
https://www.amazon.ca/Breaker-Splitt...s%2C129&sr=8-1
Otherwise I'm sure it was exactly the same tool from the same company. $22 Canadian from amazon.ca, plus shipping. (I didn't need anything else). Total $31.10 CAD.
Conversion done, and I used the tool already to push out the cotter on my Raleigh DL-1 Tourist Sir Wayes A. Tonne.
I have also ordered 2 pairs of Raleigh cut cotters from Mark Stonich Bikesmith.
When I reinstall I'll be pushing the cotters home with the press and then retightening after a bit.
Thank you so much to the OP for the design of this tool!! Much appreciated.
#109
Newbie
I ended up having to grind a slot on both sides of the casting to allow it to go over the new cotter. I couldn't quite get it over without the slots. Remember you have to push the cotter from both sides, press out and press in.
New Raleigh cut French cotters from Mark S (awesome) are now pressed in.
Wouldn't do the job without this press.
New Raleigh cut French cotters from Mark S (awesome) are now pressed in.
Wouldn't do the job without this press.
#110
Newbie
I have watched a few videos on Youtube, in which experienced people used a vice. They make it look easy.
One rolled the vice in on a skateboard.
One rolled the vice in on a skateboard.