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:

http://i132.photobucket.com/albums/q...p/DSCF1215.jpg

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. :rolleyes:

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:

http://i132.photobucket.com/albums/q...p/DSCF1213.jpg

http://i132.photobucket.com/albums/q...p/DSCF1212.jpg

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.

http://i132.photobucket.com/albums/q...p/DSCF1216.jpg

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:

http://i132.photobucket.com/albums/q...p/DSCF1211.jpg

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.

I like it! Having just had that experience (mushroomed cotter) on a Raleigh Sports I'm rehabbing, I can relate. My method was to put the non-drive side arm in my bench vise and position the frame so that fork rested on my bench. That seems to support things pretty well. From there, I first knocked off the mushroomed end of the cotter with a hammer and punch, then I took out the power drill and started drilled through what was left of the cotter. Fortunately, I didn't have to drill all the way through (though I've done that in the past with particularly stubborn cotters). Once I had made little more than a divot, I went back at it with a cotter press and a steel socket. That drove the cotter remains out.

I was lucky that there was enough room to get a good solid purchase with the cotter press as I have a couple of 50s Raleigh cranksets that have the problem you describe: there's not quite enough room between the ring and the crank arm to get the press solidly in place.

Neal

That looks like a knockoff hammer for a British sports car and a nail set.

They're cotters:

http://en.wikipedia.org/wiki/Cotter_pin

Nice jig you've built.

thanks for the idea. I've got a sheared cotter on my Norman to deal with.

nice work. Patience is truly a virtue.

Since I sincerely doubt that I'm ever going to get another chance at a Lenton, I can't afford to screw this one up.

I had trouble with a cotter the other day that I pressed half-way out and would not BUDGE any further after moving the 3/16" to where the threaded part was flush with the crank. It was one of the really worn cotters that would allow the crank to move an inch or more at the pedal without the spindle moving. I must have wedged a bit of worn metal sliver in somewhere.

It was on the non-drive side so I was able to pull it off the BB and work on it in a vise. Your issue looks like it was a PITA. I've since modified my press to accept a special longer pin that will press further into the recess in case this happens again. Here I was showing my press off to someone and attempting to look like super-wrench when the darn thing failed me. This was the most difficult cottered crank I've ever come up against -including the ones before I got a press.

I like your solution. Wood is real!

Clever jig that I have got to keep in mind for a nightmare cotter extraction.

Excellent work and very helpful for future reference of the others here.

I'm one of the most tiresome boosters of cotter presses on this forum, and even I have to admit that this is a nice method. The key things to me are:

1. Securing the bike so you're not trying to hold it in position with one hand, hold the drift in the other, and pound on it with a hammer in your third hand.

2. The long drift--lets you hit hard without worrying quite so much about bashing the crank of the bottom bracket shell with an off-target blow.

Sometimes you have to go old school.

Another one for my note book of tricks... Thanks

I'm always been about a quarter step behind you in screaming "Get a cotter press!" at the top of my lungs. After this experience, and knowing that I want to restore some older bikes than this once I'm done, I'm going to be looking for a second press - one that'll allow me to get in closer to the chainwheel. Hopefully, I can find something (most likely antique) that'll work on a situation like this. After all, 60-70 years ago, the usual instruction was to use a press, not a large hammer. Or so my mentor at the bike shop taught me.

If I can't find one, I'll pick up a new one and start machining down the main casting.