Cottered cranck
#1
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
Cottered cranck
I have an old bike (on the cheap side) that came with cottered cranck, I needed to remove the BB to clean and lub and I was wondering if I should keep it that way or switch everything to cotterless cranck. What do you guys think?
#3
multimodal commuter
Joined: Nov 2006
Posts: 19,810
Likes: 597
From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
It really depends. If your cottered crank is ugly and heavy and you have a better cotterless one in your parts bin and all the parts you need to make the switch, then what the heck, do it. Especially if you're making an upgrade that the manufacturer made within a few years of when your bike was made. Like, what's the harm in making an early 70's Super Course more like a later 70's one?
On the other hand, there are some really nice cottered cranks and it would be sad to upgrade a nice cottered one to a crappy cotterless one. Not that you'd be the first one to do that.
On the other hand, there are some really nice cottered cranks and it would be sad to upgrade a nice cottered one to a crappy cotterless one. Not that you'd be the first one to do that.
#4
Consider why you want to change it - then consider that the weight savings is in a location where it hardly makes any difference, and consider too that cottered cranks are extremely durable and often beautiful.
Also, the difficulty in servicing them is, IMO, way over-blown (provided you have a good cotter press and mill file).
Also, the difficulty in servicing them is, IMO, way over-blown (provided you have a good cotter press and mill file).
__________________
- Auchen
- Auchen
#5
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
Consider why you want to change it - then consider that the weight savings is in a location where it hardly makes any difference, and consider too that cottered cranks are extremely durable and often beautiful.
Also, the difficulty in servicing them is, IMO, way over-blown (provided you have a good cotter press and mill file).
Also, the difficulty in servicing them is, IMO, way over-blown (provided you have a good cotter press and mill file).
#6
Junior Member

Joined: Jul 2011
Posts: 17
Likes: 0
From: Coastal B.C.
I have several bikes with cottered cranks. I use a homemade press to remove and install the cotters and have not found them to be a problem. I have heard horror stories but I haven't experienced anything nasty (yet?).
Sandy
Sandy
#8
Senior Member
Joined: Nov 2011
Posts: 1,337
Likes: 6
From: Rochester, NY
Bikes: 1962 Carlton Franco-Suisse Custom,1968 Raleigh DL-1/Tourist, 1971 Holdsworth Professional, 1973 Holdsworth Mistral,1973 Raleigh Gran Sport,1974 Raleigh Grand Prix, 1993 Trek 2200 Composite, 2011 Trek 7.3FX
i have a raleigh sports 3spd with a cottered crank, i had a ***** of time removing them and a ***** of a time replacing the cotters,
once i finally got them back together i vowed i wouldn't never take them a part, i will pour motor oil down the seat tube before i screw with those cotters again, but.... i love the r nuts on the crank, and they keep the vintage of the bike intact soo i have no interest in changing the cranks
once i finally got them back together i vowed i wouldn't never take them a part, i will pour motor oil down the seat tube before i screw with those cotters again, but.... i love the r nuts on the crank, and they keep the vintage of the bike intact soo i have no interest in changing the cranks
#9
It would be good to know (maybe you already do; I don't) if the BB on that bike is French-threaded. When I converted my Gitane, I had to find a longer Italian spindle to make it work with the thin French cups. This may complicate your conversion.
FWIW, I never had much trouble with the cottered cranks. The key as far as I'm concerned is to use a press of some sort in combination with heat (propane torch) to get the cotters out intact, then clean everything thoroughly and slather the cotters with anti-seize compound when you reinstall. You'll never have a problem getting them out again. I only converted that bike because I came across a crankset I really wanted to use, and that bike was the one that suited it best.
FWIW, I never had much trouble with the cottered cranks. The key as far as I'm concerned is to use a press of some sort in combination with heat (propane torch) to get the cotters out intact, then clean everything thoroughly and slather the cotters with anti-seize compound when you reinstall. You'll never have a problem getting them out again. I only converted that bike because I came across a crankset I really wanted to use, and that bike was the one that suited it best.
#10
If pure function is your aim (I think it is ?) then
by far the easiest way to make this switch is with
the square taper crank set of your choice and
a sealed unit BB in the appropriate threading and
length/offsets.
by far the easiest way to make this switch is with
the square taper crank set of your choice and
a sealed unit BB in the appropriate threading and
length/offsets.
#11
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
How did you make your homemade press? I'd like to have one because it would be a lot cheaper to keep everything as is. I just don't want to mess around and search for cotter each time I want to lube the BB. I don't lube the BB that often but when I must I want peace of mind.
#12
Banned.
Joined: May 2011
Posts: 4,816
Likes: 29
From: on the beach
Bikes: '73 falcon sr, '76 grand record, '84 davidson
is 'cranck' the french canadian spelling? i think i'd change the cottered cranck to a cotterless crank just to avoid the confusion of cranck with crack. crack's wack.
#13
Bicyclerider4life
Joined: Aug 2006
Posts: 1,076
Likes: 12
From: Florida and Idaho
Bikes: Huffy Beach Cruisers, Miami Sun Trike, Vertical PK7, KHS Montana Summit, Giant Cypress DX, Schwinn OCC Stingray
I removed the pins on my cottered crank by loosening the nuts so they were flush with the threaded part, tapping with a hammer to get them lose, remove nuts and press out the rest of the way with my thumb. Install was press the pin in as far as I could and use the nut to draw it the rest of the way. I never had to replace a pin.
__________________
"Whenever I see an adult riding a bicycle, I know there is hope for mankind." (H. G. Wells)
"Whenever I see an adult riding a bicycle, I know there is hope for mankind." (H. G. Wells)
#14
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
#15
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
#16
Here's a nice Magistroni 5 pin that won't be replaced with a cotterless. The crank arm might look short but it's because the big ring is a 60 tooth. BTW, what's the file size limit for pics?
thanks
Brian



thanks
Brian
Last edited by calstar; 06-21-12 at 04:45 PM.
#17
Banned.
Joined: May 2011
Posts: 4,816
Likes: 29
From: on the beach
Bikes: '73 falcon sr, '76 grand record, '84 davidson
oh, please don't apologize for that. i just thought the word looked even more odd than usual. it is an odd word, with many different meanings, including 'an eccentric person' and 'meth' (the narcotic). so, you could write ...
the tired crank took crank to install his crank.
and that's not the worst idea, you know, if you're tired...
the tired crank took crank to install his crank.
and that's not the worst idea, you know, if you're tired...
#19
Really Old Senior Member


Joined: Feb 2007
Posts: 14,623
Likes: 1,879
From: Mid Willamette Valley, Orygun
Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3
I actually installed cottered cranks on a newer bike.
I needed 165MM for my bad knee.
Until I got my new (cheap) 165MM sq.taper cranks, I had an 86 RockHopper 2X9 with the dorkiest looking cranks around.
I needed 165MM for my bad knee.
Until I got my new (cheap) 165MM sq.taper cranks, I had an 86 RockHopper 2X9 with the dorkiest looking cranks around.
#20
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
oh, please don't apologize for that. i just thought the word looked even more odd than usual. it is an odd word, with many different meanings, including 'an eccentric person' and 'meth' (the narcotic). so, you could write ...
the tired crank took crank to install his crank.
and that's not the worst idea, you know, if you're tired...
the tired crank took crank to install his crank.
and that's not the worst idea, you know, if you're tired...
#21
If you want to improve your french : https://www.infovisual.info/05/034_fr.html
__________________
- Auchen
- Auchen
#22
Thread Starter
ouate de phoque
Joined: Mar 2012
Posts: 1,781
Likes: 1
From: La Prairie, Qc, Canada
Bikes: Bianchi, Nakamura,Opus
#24
Senior Member
Joined: Oct 2011
Posts: 2,714
Likes: 13
From: Normal, Illinois
Bikes: Trek 600 ,1980Raleigh Competition G.S., 1986 Schwinn Passage, Facet Biotour 2000, Falcon San Remo 531,Schwinn Sierra, Sun Seeker tricycle recumbent,1985 Bianchi Squadra
Use a large, cast clamp and an old wrench socket to create a negative space for the cotter to come into as you press it out with the clamp . It seems to be the only way to remove these reliably, other than a cotter press .
#25
In times of desperation, I've used a bench vise with a socket (requires some
wrestling with the frame to position it,) and a twenty dollar drill press vise
from Home Depot (awkward, but less awkward than the bench vise.)
Just don't hammer them.
wrestling with the frame to position it,) and a twenty dollar drill press vise
from Home Depot (awkward, but less awkward than the bench vise.)
Just don't hammer them.





