Old 07-12-11 | 03:16 PM
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sykerocker
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Joined: Dec 2005
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From: Ashland, VA

Bikes: The keepers: 1969 Magneet Sprint, 1971 Gitane Tour de France, 1973 Raleigh Twenty, 3 - 1986 Rossins.

My method for removing a snapped cotter pin

Over the past three months, bit by bit, I've been slowly restoring the '58 Raleigh Lenton I picked up from Poguemahone. It's been pretty much a process of removing each component, disassembling, soaking in an oxalic acid bath (if necessary), re-polishing, and storing the finished components. Finally got down to removing the drive side of the crankset.

I immediately discovered a rather unpleasant situation: The cotter pin on the drive side is placed much closer to the outside chainwheel than on a '60's or '70's bicycle. The tolerance was tight enough that the body of my cotter pin remover didn't have enough clearance to fit straight onto the cotter pin. Having no other particular options, I gave a shot at removing the cotter pin using the tool at a bit of an angle.

Of course, all I succeeded in doing was snapping the threaded part of the cotter pin off. Now comes the fun part. I'm going to have to use a hammer and punch to drive the (very well lodged) cotter pin out. Critical to this operation is keeping the frameset steady and well supported. Given how I'm going to have to hammer, this isn't the time for a well-meaning volunteer to try and hold the frame steady. Oh yeah, since I'm not certain about the dimensions of the original spindle compared to a '70's equivalent, I can't risk bending of damaging the spindle.

After a little thought, I came up with the following:



Made it out of some scrap 2x4 and 2x2 stock. The 2x2 uprights are 3.9" high (enough to clear the chainwheel with about .3-.4" spacing), and are spaced 3.4" wide (yes, my tape measure is divided in tenths, not eighths). That's a 15/32" hole drilled right at the edge of the chainwheel side support - the cotter pin has to go somewhere when you hammer on it.

When the frame is placed in the jig, it supports the crankset on the crank arm on the chainwheel side, against the spindle on the other side, and the supports are close enough to fit tightly. Once the frame is pressed onto the jig, friction will keep the two together if the frame is lifted:





A nice, subtle hammer, long steel bar, and a drift punch gives me enough force to loosen the cotter pin, and then push is completely through once its loosened.



Realizing I'm going to have to hammer HARD, I need the entire frame braced so it won't bounce in between hammer strokes (at this point I had no idea how much hammering was going to be necessary to loosen the cotter pin). Fortunately, I've got my motorcycle work stand in the shop, with a number of tie down points on it, so securing the entire frameset was no problem:



In the end, it took five good, strong swings of the hammer to crack the cotter pin loose from the assembly, then a couple of lighter taps on the drift pin to drive it completely through.

Now, just pull the bottom bracket and headset, and I can started on the difficult job: Cleaning the frame without damaging the decals.

I'm happy enough with the jig that I'm going to give it a quick go-over with the belt sander to remove the rough edges, and then a coat or two of varnish for finishing before putting it on the rack with my other shop tools.
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Syke

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