I_bRAD

Hey All,

Tried the search and didn't find what I was looking for:

I've recently acquired an old Raleigh for my girlfriend and this will be my first experience with cottered cranks. One is loose, and is missing the nut. The other side seems to be fine.

So... is the nut on the pin an odd thread or will I be able to obtain a replacement at any hardware store?

For removing and installing the cranks- is there any reason I can't use a shop vise to press/remove?

Thanks for any tips!

iab

Sheldon Brown has all you need to know about cottered cranks.

https://www.sheldonbrown.com/cotters.html

miamijim

1. In most cases removing cotters damages the threads. Therefore you dont need to worry about finding properly threaded nuts at Home Depot. You did mention its loose so just remove it and see it you can find a nut.

2. Shop presses? You may find the chainrings interfere with use of the press. If there's no interference then...a press is a press.

I had 8 stiches in my palm from removing a broken cotter.

San Rensho 

Cotterd cranks are the biggest PITA bike repair in my book. In your case, since one is loose, it should be fairly straight forward. If the cotter is stripped, get a new one which may entail some filing to get it to fit. Be sure everything is clean and greased, put the cotter pin into the crank/axle and then put a socket over the the non threaded side of the cotter use a big c-clamp to drive the cotter.

twobikes

Once I was able to cut new threads on the stud portion of a cotter by using a die just a little smaller in diameter than the original threads. I could not get it to work the next time I tried it on another cotter. I did successfully weld a new 1/4 x 20 stud onto an old cotter. I would not have tried it, except it is getting harder to find cotters at an LBS. I used a 220 volt stick welder with a 1/16" rod and a heat setting a bit high for that rod. I champfered the shoulder of the old cotter and the new stud a little. The object was to get in, melt both faces quickly and get out just as quickly. I have quite a few miles on that cotter now and it has been fine. I have since ordered new cotters from Harris Cyclery, but the welding got me through a tough spot. It worked so well that I would do it again.

Little Darwin

I have seen Raleigh cotters and nuts regularly on eBay, usually in the collectibles area.

Also, any press that can get a good grip should work.

I bought one of these:

https://www.bikesmithdesign.com/CotterPress/

It has worked very well. An LBS that has been around for a while could probably help you with removing or installing a cotter as well.

BigBlueToe

I had a Raleigh Gran Prix in the 70's that had cottered cranks. I agree that they are a PITA. Mine were always coming loose and would creak every time I pedaled. I don't know how hard or expensive it would be to upgrade to modern cranks, but if it were miy bike I'd look into it.

CharlesC

It's not hard to change to modern cranks. You will have to use the Raliegh BB cups because they use a proprietary thread that nothing else fits. I changed my wife's old rusty park trail bomber to a Stronglight with a 45 tooth inner chainring moved to the outside position. I think I used a Stronglight spindle but may have used a Sugino.

rykoala

When taking cotters out on an old bike I got for free (for parts) I simply loosened the nut so it was still threaded a bit, then beat on the nut with a hammer. That loosened the cotters. Then I took the nut off the rest of the way and the cotters came right out. Took 5 minutes. I've never installed new ones though.

Coyote!

Rycoala spake. . .

>>> simply loosened the nut so it was still threaded a bit, then beat on the nut with a hammer.

Mind, cotters are rather soft, so take it easy. Sad experience.

Also, you can still get cotters in most sizes at Loose Screws https://www.loosescrews.com/ and Bike, Tools, Etc https://www.biketoolsetc.com/

John E

That has been my traditional response, but since Capo #2 is almost all-original, including an Agrati cottered crankset in which the drive side crank and spider are a one-piece casting, I am currently working with cottered cranks again, after a 15-year hiatus. So far, mine are actually cooperating nicely, cotters and all.

twobikes

That is the ideal, but it does not always go so well. One cotter may be very stuck, and the force required to loosen it with a hammer still damages the threaded stud, even when using the nut to protect the threads.

San Rensho 

You were lucky, I started hammering with the nut on, the threads stripped, so I hammered on the end of the cotturd, it mushroomed, so I filed it some, and took a huge C-clamp to it, clamp broke, bought another clamp, hit the cotturd really hard with a torch, C-clamp wouldn't budge it. I gave up.

CharlesC

I don't remember what bike it was on, but I had one that was stubborn like that. Cotter would't budge no matter what I did. I finally had to resort to drilling it out. Not fun. I would suggest you try Kroil penetrating oil. It helps loosen stuck metal stuff better than anything else on the market.

San Rensho 

Thanks, the bike got stolen so no more cotturd problem!

JanMM

That's impressively rusted but the crankset looks great.

miamijim

In England, where that bike was made, they call it 'patina'.