Cottered Cranks
 

I am going to try to overhaul a old Raleigh Record (mid 70's) and it has a cottered crank. I have never had agood experience with a cottered crank removal and reinstallation.

Is there a some good instruction or method to removing one and reinstalling?

Rule #1 Plan on replacing the cotter; if you know the size (they come in about many sizes), go out and buy them before you start
Rule #2 Loosen the cotter nut but and leave the nut on to protect the threads in case to can't find a replacement (but it might not be re-useable)
Rule #3 Use a punch to knock out the cotter and hit it with as much force as you can reasonably direct toward the cotter, don't try and tap it out.
Rule #4 Once it's out, if you haven't already, go out and get a replacement.

Check this site for more info http://sheldonbrown.com/tooltips/cotters.html

1. Remove cottered crankset.
2. Get appropriate square taper spindle.
3. Replace cottered crank with aluminum cotterless crankset.

1) Use a proper cotter press to remove the pins.

2) Use a proper cotter press to re-install the pins.

I'd start by applying penetrating oil NOW, even if it'll be a few days before you actually remove them.

I used a 4" machinist's "C" clamp (fine threads) and a 10mm axle spacer as a "receiver " with great success on the only one I've tackled.
I did start using the penetrating oil a couple days before and applied it several times/day.

use a cotter press or have some steel tubing as an anvil supporting the crank arm

+1 If you use a hammer, not a screw press, NEVER pound on the end of the cotter without completely supporting the crank arm. Otherwise you will damage the bottom bracket and frame. Bill Kapaun's improvised cotter press is definitely the way to go for a one-time job that doesn't warrant buying the purpose-built press.

I would like to thank everyone for their suggestions, I have called a lbs and they will repack the bottom bracket for less than the proper tools (cotter pin press or machinist clamp, I do have a hammer) will cost me. So I will suggest that to my friend. When I initially looked at the bike, I told him that the bottom bracket would be a problem for me, but I thought that some experience on the forum would be helpful in determining whether I should undertake this part of the overhaul.

And I won't be using a hammer that normally get me in trouble on bikes.

http://bikesmithdesign.com/
The best cotters and cotter press you can buy. Don't use anything else or cheap cotter pins. Not worth the headache.

Easiest way to remove a cotter pin is to remove the nut and go for a cycle ride, it will just fall out at the point furthest from your home :D
This actually works!

The overall best solution.

Sensible and very gratifying.:thumb:

I like this, but have not yet had a chance to modify one. It's on my list.:o

Yet another bargain, slightly less ideal solution than #1.

I've got one of these, but have not had the opportunity to try it out yet. No problems dealing with Mark. He had my order in the mail the same day I sent it. Great service.

Not use hammer? But, hammer big! Like hammer.
But seriously, when I worked on bikes (casually) thirty years ago, I hated cottered cranks. There has never been one that didn't cause trouble.

Between JohnDThompson and Fenway, the OP has all the information he needs. IMO, much of the bad rap given to cottered cranks is due to improper installation and removal. With the proper tool and good cotters, cottered cranks are as reliable and as easy to work on as anything else.

This for sure! I had an old Peugeot that used cottered cranks. I HATED them!! Most annoying!! I loved the bike but man those cottered cranks SUCKED!!

Well, given the proper tools, parts and experience they are functional but there are a lot of good reasons they've disappeared from newer bikes and by newer I mean anything made in the past 30+ years. Cottered cranks are HEAVY and offer no benefits over newer square taper designs.

The last cottered cranks I had to deal with were on a friends '71 Raleigh Super Course with Stronglight (which were strong but certainly not light) cottered cranks. I managed to remove them with minimal problerms and no damage but we immediately replaced them with an SR square taper crank and matching spindle. We had to keep the Raleigh's bottom bracket cups since they had their proprietary threading but the new spindle was adequately compatible with them. Overall we must have reduced the bike's weight by a pound and opened up a world of newer and better chainring choices.

Good cottered cranks are not actually very heavy. And they have the benefit of lower tread than any aluminum crank. IMO top quality cottered cranks are better looking than any aluminum cranks as well.

I would never go on record as saying that cottered cranks are better than modern cranks. I just think they receive more than their share of unwarranted criticism. Assembled correctly, good quality cottered cranks work perfectly, look great and only add a few ounces compared with modern aluminum cranks.

+100 You hit on the head Six jours!

Looks are subjective but weight is not. The Stronglight cranks I dealt with were solid steel and as heavy as an anvil and MUCH heavier than any aluminum crank I've ever worked on. The weight difference was not insignificant. Also, the chainring selection was very limited and no longer commonly available. Other than the bike already has them and you don't want to go to the replacement expense or you want to keep the bike "period correct", I see absolutely no advantage to keeping them.

+1, while there's nothing wrong with cottered cranks, the design doesn't work with aluminum cranks. In order to move forward with lighter cranksets, cottered had to give way to alternate mounting systems.

If you're working from a sample of one then I can understand your complaint. But as I've mentioned, there were many top quality steel cranks that were not very heavy. For example, the Magistroni cranks that I have on my four speed are 70 grams heavier than the Super Record cranks on my Italian road racer. I don't know if you consider that significant, but I certainly don't.

Even if I agree with that, what does it have to do with the supposed limitations of cottered cranks? Regardless, I have half a dozen NOS 101 chanrings hanging on a peg. They weren't very hard for me to find, in the internet age.

"Already on the bike" seems like a pretty important factor to me, especially in light of the inevitable "Throw them away and get good cranks!!!" responses on threads like these. Again, I'm not arguing that people should be taking off their modern cranks and substituting cottered ones. I'm simply pointing out that the reasons people often list in support of "Throw them away and get good cranks!!!" are specious. It's hard to see any reason why the OP should replace his existing cranks when they've worked just fine for decades.

I was going to take some pictures of various cottered and aluminum cranks on my scale, but for the life of me I don't know where the scale went. The best I can find is this Velobase entry http://www.velobase.com/ViewComponen...115&AbsPos=115 which lists the weight of the medium-to-low end Ofmega cottered steel crank with single ring as 871 grams. This seems to compare pretty well with modern low-end aluminum cranks listed at Weight Weenies. http://weightweenies.starbike.com/li...y=manufacturer

Of course, as I mentioned it's perfectly possible to save a bit of weight by replacing cottered cranks with modern ones. Assuming the OPs cranks aren't any heavier than the Ofmega junk, he could save almost a half a pound by putting on some Record Carbons. And of course, taking his forty year low Raleigh from 29 pounds to 28.5 pounds will make all the difference! :p

It would be interesting to see how the hollow steel Duprat cranks compare with cotterless aluminum. Anybody have a set to weigh?

http://www.velobase.com/CompImages/C...B03AF239B.jpeg