Cottered cranks

I've picked up a frame that has a cottered bottom bracket so I need to get the right cranks.

Should I look at replacing the bb or tracking down some cottered cranks for this ?

I've not got any experience with the world of cottering !
Andy.

do you need the bottom bracket?
the word from skully on matters like this when i spoke to him was "replace that and put something else on. don't mess with cotters".

but said in a more erudite fashion.

hah cheers, ok.

I have the bottom bracket already fitted and i don't want to open up a can of worms if i have to replace it (its quite an old frame and god only knows what thread it has if there is one at all).

I'd be interested to know what the problems are with cotters i think to way up the options. perhaps sheldon can help.

I'd keep the cottered cranks if it is for a period build and you wish it to look homogenous/correct.

If you are stripping it and converting it then bin the cottered cranks and get something a bit more modern.

I'm going to ss it but definitely going for that classic look.

Going to read up on cotters and see if i can get some off ebay or at the bike jumble @ herne hill.

thanks all.

My 2p:

If it's important to you that your crankset is period correct for your frame, search Ebay or jumbles such as Ripley for manufacturers like Chater Lea, Stronglight, TA, or Williams (these are good and tend to sell relatively cheap). Probably best avoid 'sleeve fitting' cranks, go for ones that have bolts to hold the rings.

If, however, you are not set on using 'correct' cranks, you might do well to sell your BB. Cottered cranks are a world of pain, in my experience. Be sure to name it by manufacturer if you try to sell it. Baylis Wiley and BSA are OK quality, Chater Lea are desirable (to a certain kind of people), as are Brampton. All of this supposes the cups and axle are in good condition.

Then go and buy a decent cotterless crank set. They're a lot less hassle to get working well.

If you want to research all the cottered stuff, look here:
http://www.classiclightweights.co.uk/components.html

Cheers

PS. Look in at Rob Sargeant, Sargeant and Co, in Finsbury park, he may well have some cranks for you.

i haz all the bits apart from a bottom bracket lockring, should someone want to investigate the world of cottered cranks.

available for not much. probably.

If you want a cheap pair of cottered cranks, Cycles of yesteryear in Surbiton stock them (http://www.cyclesofyesteryear.com/cycleshop/sparepart.htm) he occasionally gets used ones which are probably higher quality ( I can't imagine the £10 are great quality!)

when you have a cotterpin that is slipping and does not marry well with the axle your bicycle will feel like a tired old man, when you fix this cotterpin securely your bicycle will feel like a young sprightly fellow.

I'll drop them both an email to see what they suggest. I've had the frame from a while now and just want to get it up and running so my girlfriend has a bike!

I can upgrade at a later date when I know exactly what I want.

when you have a cotterpin that is slipping and does not marry well with the axle your bicycle will feel like a tired old man, when you fix this cotterpin securely your bicycle will feel like a young sprightly fellow.

This is true.

But you need the patience of a Buddhist Monk to achieve this.

This is true.

But you need the patience of a Buddhist Monk to achieve this.

your right! go cotterless :-)

I live a few doors down from rob sargent, nice bloke and knows his onions.
He helped me build my first fix which was a 60's pennine conversion with cottered cranks. I ran them for about 8months with no trouble until i retired the pennine to france this summer.
Some thoughts on my cranks:
New cotter pins from ebay are of TERRIBLE quality(this may not always be the case but the 3 pairs i got were shite, eventually got a pair made by a machinists in hackney somewhere). Smack them in good and hard with a hammer and tighten the bolts with a much bigger washer than the ones provided with the new pins. Don't go mad with the bolts otherwise you risk stripping them.
They do work loose now and again so keep them tight. Getting a chainline was easy at robs shop as there was a few cottered axles knocking around the shop and we got it right first time.
I had a cheaper raleigh chainset from the bonk, not the same quality as a chaterlea but it had almost no wear and worked just dandy.
Rebuilt the bb with fresh grease 2-3 times in 8 months which does involve removing the cotter pins. Rob has a special tool for this which was required for removing old seized pins. With the new ones i could remove them with screwdriver and hammer and reinstall them easily.

If its a cheap build then go for it, did me just fine. Then again i'm no racer/curryer so don't put bikes through the same use as many on here.

Rob removed the old knackered cotter pins from my Freddie Grubb - he has both the expertise and the tool (although it might actually belong to Eric Deeks); replaced with pins bought from Two Wheels Good in Stoke Newington if I remember correctly.

Like Edmundro, I don't put the bike through heavy usage, but they have worked a treat since replacement about three months ago.

as ppl said above, only keep them if your trying to be symathetic to the bikes age. My experience as a mechanic tells me that they are fine until you have a problem then they fucking suck! especially if you hope to work on your own bike. Also as Edmundro says most stuff available readily now is of pretty rubbish quality and the rest will probably be NOS and therefore generally exorbitantly expensive. For reliability just change up to a regular tapered design, a bb will only cost you £10-20.

I've had mixed experience with this pin business. Built a Claud with Chater leas a while back, after a bit of trial and error (filing the faces of the pins (old good ones) til they sat snugly) it all worked a treat for a good year of daily riding.

Then moved all the components, same pins, to a new bike. Never got them to work well, think I may have ruined the cups with hammering the pins in and out. And the pins just wouldn't sit well. Gave up.

Spudger mentions Rob having the right tool - a cotter pin press. It's an important detail. Unfortunately you'd have to go back every time you wanted to remove the pins to file them a bit.

+1 on the cotterless. You can get nice-looking cranks to work well, a lot more easily. Stradas 'for the win' (shudder).

see. i told you he said it in a more erudite fashion.

I used the orginal c.cranks on my first fg.

+1 to almost everything said so far - eps. edmundro

[QUOTE=edmundro;960587]
Some thoughts on my cranks:
New cotter pins from ebay are of TERRIBLE quality(this may not always be the case but the 3 pairs i got were shite, eventually got a pair made by a machinists in hackney somewhere). Smack them in good and hard with a hammer and tighten the bolts with a much bigger washer than the ones provided with the new pins. Don't go mad with the bolts otherwise you risk stripping them.
They do work loose now and again so keep them tight. QUOTE]

overall prob best to just buy a new BB, plus you'll def get the chain line you want.

that does make sense but if i have a freewheel converter kit i can use spacers to adjust my chainline right?

I'll have a look to see how easy it is to remove the bottom bracket. I also don't know what threading takes and balancing this minefield off with using cottered cranks should be fun.

may be a job for brixton cycles.

at the cycle jumbles there is a man that sells little shims that go inside the bottom bracket to improve the chainline and help if you need to take the chainset further away from the chainstay. this remedy was suggested to me when i explained the problem that i had to a seller at the herne hill jumble. i havent tried this method yet.

hope that helps.

I have a double williams chainset in half decent condition if you wanna go cottered

Never needed a cotter press in my bike-fixing life - which goes back to 1952.

The secret to getting them out isn't complicated:
1: Undo nut, remove washer. Spray both ends with penetrating oil or WD40. Leave for some hours.
2: Replace nut, without the washer. But leave it loose, so its top face is level with the end of the pin.
3: Remove the bike's wheels.
4: Find a steel tube (I use a tube spanner) that is a loose fit around the head of the pin, and longer than half the diameter of the chainwheel.
5: Perch the bike on the tube, so the head of the cotterpin is inside the end of the tube, and the bike's weight is sitting on the crank head, on the tube. Which is on a solid concrete floor.
6: Take a large round punch, that covers both the end of the pin thread, and the nut.
7: Hit it once, VERY hard, with a 2lb. hammer.
8: Remove the nut (this will ease out any thread distortion caused by the punch)
9: Continue with the punch, directly on the cotterpin. It should now come out without much more force.

NB. Yes, as you'll have noticed, this does need four hands. So you need an assistant.

The key point is to take the force of the hammer-blow directly from the crank head to something solid, NOT passing it through the bb bearings and the frame. Apart from wrecking the bearings, that robs the hammer-blow of most of its impact force.

If you have to do this frequently, there are two more specialised methods:

1: Make up a ''closed sleeve nut'' - that screws onto the cotter in place of the normal nut, is closed at the top, and is slim enough to fit into the cotter-hole in the crank head. Make sure the thread in the nut has enough 'headroom' that the end of the nut bears directly onto the unthreaded shank of the cotter.

2: Use an ultrasonic driver, holding it directly on each end of the pin in turn.

 – remember Doctor Who's Ultrasonic Screwdriver?  Well, this is it!

Never needed a cotter press in my bike-fixing life - which goes back to 1952.

The secret to getting them out isn't complicated:
1: Undo nut, remove washer. Spray both ends with penetrating oil or WD40. Leave for some hours.
2: Replace nut, without the washer. But leave it loose, so its top face is level with the end of the pin.
3: Remove the bike's wheels.
4: Find a steel tube (I use a tube spanner) that is a loose fit around the head of the pin, and longer than half the diameter of the chainwheel.
5: Perch the bike on the tube, so the head of the cotterpin is inside the end of the tube, and the bike's weight is sitting on the crank head, on the tube. Which is on a solid concrete floor.
6: Take a large round punch, that covers both the end of the pin thread, and the nut.
7: Hit it once, VERY hard, with a 2lb. hammer.
8: Remove the nut (this will ease out any thread distortion caused by the punch)
9: Continue with the punch, directly on the cotterpin. It should now come out without much more force.

NB. Yes, as you'll have noticed, this does need four hands. So you need an assistant.

The key point is to take the force of the hammer-blow directly from the crank head to something solid, NOT passing it through the bb bearings and the frame. Apart from wrecking the bearings, that robs the hammer-blow of most of its impact force.

If you have to do this frequently, there are two more specialised methods:

1: Make up a ''closed sleeve nut'' - that screws onto the cotter in place of the normal nut, is closed at the top, and is slim enough to fit into the cotter-hole in the crank head. Make sure the thread in the nut has enough 'headroom' that the end of the nut bears directly onto the unthreaded shank of the cotter.

2: Use an ultrasonic driver, holding it directly on each end of the pin in turn.
– remember Doctor Who's Ultrasonic Screwdriver? Well, this is it!

Or you could just ride for a bit. In my experience they will get wobbly within weeks and fall off completely in a matter of months.

I've got the first twinges of movement on a cottered crankset on one of my bikes at the moment. I'm considering using my "ride until it falls to bits" method again.