Cottered cranks, the cheap brute force method is to turn the crank 180 degrees and support the crank arm/spindle on a piece of wood and beat on the pin. It might be good to put a bit of penetrating oil in there and let it set for a few hours first. The actual tool is called a copper pin press IIRC and its a C shaped block of steel with a threaded driver to remove and set pins. If you plan on replacing the bottom bracket with a square taper I’d probably go with the brute force method. I think I’ve seen YouTube videos of someone who made their own pin press.
pensive_pigeon on
I’ve had success using a soft face hammer. Alternatively you can leave the nut on but loosened and hit that with a hammer. You want to be careful hitting the threaded part so you don’t damage the threads. There are special tools for removing the pin, but probably not worth buying unless you’re going to do this a lot.
SingleLifeSingleBike on
I always love it when people ask this question once in a while.
Like, cotter pin cranks was a dumb-ass idea 60 years ago, and still amazingly dumb now.
As much as I hate them, I used to make them out of old pedal spindles. Worked nice.
AndyRaleigh on
Hardest job I’ve ever done on a bike was removing these from an old Raleigh roadster, it really puts me off buying otherwise cool bikes when I see they have cottered cranks.
The only presses that work without breaking are quite expensive so if a soft faced hammer doesn’t do it just drill ’em out.
thisquietplace on
Angle grinder and a thin metal blade is a good option if it’s going in the recycling afterwards, just cut the bottom bracket axle
Darnocpdx on
Deep well socket/piece of pipe that doesn’t touch the blunt side of the pin a little longer than the pin, remove nut, use a c clamp positioned on the threaded side and socket, and tighten the clamp.
Would hit it with pb blaster or other lube generously before and durring.
If you’re simply trying to lube it. A couple good squirts/table spoons of straight 30 weight oil, not synthetic or with additives, down the seat tube does the trick.
scarletredvolare on
Back off the nut a bit and beat it with a hammer. With the nut still on the threaded section, you can sometimes reuse the pinch pin. If you beat the threaded section without the nut, you will tend to mash down the threads. If that happens, use a punch and a bmfh to pound it out. I’ve removed hundreds of these. Better yet, break out your angle grinder and cut the spindle just behind the crank, then cut off the bottom bracket, the headtube and the seat lug. They all suck and were used on shitty, weak, cheap steel bikes.
8 Comments
You need a cotter pin removal tool
http://bikesmithdesign.com/CotterPress/
Cottered cranks, the cheap brute force method is to turn the crank 180 degrees and support the crank arm/spindle on a piece of wood and beat on the pin. It might be good to put a bit of penetrating oil in there and let it set for a few hours first. The actual tool is called a copper pin press IIRC and its a C shaped block of steel with a threaded driver to remove and set pins. If you plan on replacing the bottom bracket with a square taper I’d probably go with the brute force method. I think I’ve seen YouTube videos of someone who made their own pin press.
I’ve had success using a soft face hammer. Alternatively you can leave the nut on but loosened and hit that with a hammer. You want to be careful hitting the threaded part so you don’t damage the threads. There are special tools for removing the pin, but probably not worth buying unless you’re going to do this a lot.
I always love it when people ask this question once in a while.
Like, cotter pin cranks was a dumb-ass idea 60 years ago, and still amazingly dumb now.
As much as I hate them, I used to make them out of old pedal spindles. Worked nice.
Hardest job I’ve ever done on a bike was removing these from an old Raleigh roadster, it really puts me off buying otherwise cool bikes when I see they have cottered cranks.
The only presses that work without breaking are quite expensive so if a soft faced hammer doesn’t do it just drill ’em out.
Angle grinder and a thin metal blade is a good option if it’s going in the recycling afterwards, just cut the bottom bracket axle
Deep well socket/piece of pipe that doesn’t touch the blunt side of the pin a little longer than the pin, remove nut, use a c clamp positioned on the threaded side and socket, and tighten the clamp.
Would hit it with pb blaster or other lube generously before and durring.
If you’re simply trying to lube it. A couple good squirts/table spoons of straight 30 weight oil, not synthetic or with additives, down the seat tube does the trick.
Back off the nut a bit and beat it with a hammer. With the nut still on the threaded section, you can sometimes reuse the pinch pin. If you beat the threaded section without the nut, you will tend to mash down the threads. If that happens, use a punch and a bmfh to pound it out. I’ve removed hundreds of these. Better yet, break out your angle grinder and cut the spindle just behind the crank, then cut off the bottom bracket, the headtube and the seat lug. They all suck and were used on shitty, weak, cheap steel bikes.