Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Cottered Crank Spindle has Rounded Flat?

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

Cottered Crank Spindle has Rounded Flat?

Old 08-18-21, 02:16 PM
  #1  
1989Pre 
Standard Member
Thread Starter
 
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,216

Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1280 Post(s)
Liked 892 Times in 471 Posts
Cottered Crank Spindle has Rounded Flat?

When I got my frame back from the painter's, I put the components, including the bottom bracket and crank back on. Same b.b., cotter pins and crank. Now, every time my pedal stroke reachers the 12 o clock position on the n.d.s., the crank arm slips forward about 7mm. I have experience with cotters, and use a nice Bikesmith press, but I have not found the cure for this.
I've tried filing the pin more, putting it in farther, trying new cotters,

etc.
Interestingly, when the pin is just resting in the hole, against the flat, the crank arm has no play. It's only after I use the press that I get this play.
I am trying, now, to determine if it is the spindle that is the problem, so am including some photos,
in case one of you can tell me if the leading edge of the n.d.s of the spindle is rounded enough to
cause this sort of play. It does appear slightly mis-shapen.

Last edited by 1989Pre; 08-18-21 at 02:27 PM.
1989Pre is offline  
Old 08-18-21, 02:43 PM
  #2  
juvela
Senior Member
 
juvela's Avatar
 
Join Date: Feb 2013
Location: Alta California
Posts: 14,321
Mentioned: 414 Post(s)
Tagged: 1 Thread(s)
Quoted: 3780 Post(s)
Liked 3,284 Times in 2,145 Posts
-----

do not see anything amiss in images

normally symptoms such as you describe are due to poor fitment or poor matching

appreciate you know what you are doing

are wedgebolts new or used?

if new, what sort of marks can you see on the flats when you disassemble?

how much head is showing following fitment?

beast appears British so would assume 9.5mm cotter

---

my guess -

if cotters correct and well matched seating them with greater pressure will likely eliminate the symptom

-----

Last edited by juvela; 08-18-21 at 02:58 PM. Reason: addition
juvela is offline  
Likes For juvela:
Old 08-18-21, 02:51 PM
  #3  
markk900
Senior Member
 
markk900's Avatar
 
Join Date: Jan 2007
Location: Ontario
Posts: 2,649
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 478 Post(s)
Liked 634 Times in 336 Posts
Perhaps try both cotters inserted from the other side of the crank arm?
markk900 is offline  
Likes For markk900:
Old 08-18-21, 03:19 PM
  #4  
randyjawa 
Senior Member
 
randyjawa's Avatar
 
Join Date: Apr 2007
Location: Thunder Bay, Ontario, Canada - burrrrr!
Posts: 11,672

Bikes: 1958 Rabeneick 120D, 1968 Legnano Gran Premio, 196? Torpado Professional, 2000 Marinoni Piuma

Mentioned: 210 Post(s)
Tagged: 0 Thread(s)
Quoted: 1370 Post(s)
Likes: 0
Liked 1,743 Times in 934 Posts
Make sure that the cotter pins are not all the way through the crank arm. Usually, they should go all the way through without sticking out. I always check this carefully and add ensurence with a washer that has a slightly larger hole diameter that the outside diameter of the pin.

When I press the cotter into place, I snug both crank arms slightly and then look to ensure that they are parallel to one another. If satisfied, I start the super snug up process...

Snug up the cotter with the press a lot then give it three taps or hits with a steel hammer, forcing the pin further into its fit. Now, snug up the press a wee bit (it will most likely turn easily at first) and tap again. Snug the press, tighten the press and tap again. I continue to do this until I get no more turn when I go to re-snug the press.

When hitting the press head, do not be shy. Give it a decent three smacks with a steel hammer. You would be wise to support the crank assemble to prevent the impact from damaging bottom bracket bearings, and/or races. This is my home made press. The head on the screw has mushroomed even more that it appears in this picture...


It is a slow process but does work well when done correctly. Now, make sure the round of the cotter is not sticking past the crank arm fit. If no, install the cotter pin nut and washer. If yes, install a washer with a hole larger than the cotter round, once again ensuring the the round does not stick out.

Finally go for a ride but stick close to home. After the ride, remove the cotter nut and use the press again to ensure that the cotter has not slipped or worked its way into a better fit. I know this sounds silly but this final check is important. If the press does turn, go through the snug and tap procedure again.

Now you know my secret about installing cottered cranks...
__________________
"98% of the bikes I buy are projects".
randyjawa is offline  
Likes For randyjawa:
Old 08-18-21, 04:11 PM
  #5  
verktyg 
verktyg
 
verktyg's Avatar
 
Join Date: Jul 2006
Location: SF Bay Area
Posts: 4,035

Bikes: Current favorites: 1988 Peugeot Birraritz, 1984 Gitane Super Corsa, 1980s DeRosa, 1981 Bianchi Campione Del Mondo, 1992 Paramount OS, 1988 Colnago Technos, 1985 RalieghUSA SBDU Team Pro

Mentioned: 207 Post(s)
Tagged: 0 Thread(s)
Quoted: 1036 Post(s)
Liked 1,236 Times in 653 Posts
BITD, especially during the height of the Bike Boom Fad, many makers, especially the French (Gitane in particular) were using cotters that were Wayyyy to soft. They easily distorted and worked loose. It was difficult to find hardened after market cotters. We used to get some from Zeus that were strong and through hardened but expensive. We reserved them for better quality bikes that had cottered cranks.

I was a forceful masher back in the early 70's and had to replace the cotters on my 1972 Gitane Gran Sport almost monthly because the crank arms worked loose.

Those soft cotters were one of the impetuses for the adoption of cheap cast aluminum (melt forged euphemism) cotterless cranks that became De rigueur on decent lower priced bikes by 1975...

There was nothing wrong with quality cottered cranks with good cotters. But hey, looks were everything and that's what sold bikes!

randyjawa those forged steel Stronglight cranks with alloy chainrings pictured above were handsome!

verktyg
__________________
Don't believe everything you think! History is written by those who weren't there....

Chas. ;-)

verktyg is offline  
Likes For verktyg:
Old 08-18-21, 06:12 PM
  #6  
randyjawa 
Senior Member
 
randyjawa's Avatar
 
Join Date: Apr 2007
Location: Thunder Bay, Ontario, Canada - burrrrr!
Posts: 11,672

Bikes: 1958 Rabeneick 120D, 1968 Legnano Gran Premio, 196? Torpado Professional, 2000 Marinoni Piuma

Mentioned: 210 Post(s)
Tagged: 0 Thread(s)
Quoted: 1370 Post(s)
Likes: 0
Liked 1,743 Times in 934 Posts
Originally Posted by verktyg
BITD, especially during the height of the Bike Boom Fad, many makers, especially the French (Gitane in particular) were using cotters that were Wayyyy to soft. They easily distorted and worked loose. It was difficult to find hardened after market cotters. We used to get some from Zeus that were strong and through hardened but expensive. We reserved them for better quality bikes that had cottered cranks.

I was a forceful masher back in the early 70's and had to replace the cotters on my 1972 Gitane Gran Sport almost monthly because the crank arms worked loose.

Those soft cotters were one of the impetuses for the adoption of cheap cast aluminum (melt forged euphemism) cotterless cranks that became De rigueur on decent lower priced bikes by 1975...

There was nothing wrong with quality cottered cranks with good cotters. But hey, looks were everything and that's what sold bikes!

randyjawa those forged steel Stronglight cranks with alloy chainrings pictured above were handsome!

verktyg
I could not agree more about my cottered Stronglight Competition crank set. In truth, I am a cottered crank freak...


Bought this take off (basically NOS) Legnano set complete with bottom bracket off of Ebay for a hundred bucks plus shipping. Swapped the Leggy rings and spider for Simplex and alloy rings...



Nothing too special about the set on my Torpado and, because I forgot the snug and tap thing, they came loose on my test ride. Limped the bike home, fixed the problem and been cotter spinning ever since. I really like my entry level Torpado! Perhaps my favorite bike in my little stable these days...
__________________
"98% of the bikes I buy are projects".
randyjawa is offline  
Likes For randyjawa:
Old 08-18-21, 06:44 PM
  #7  
verktyg 
verktyg
 
verktyg's Avatar
 
Join Date: Jul 2006
Location: SF Bay Area
Posts: 4,035

Bikes: Current favorites: 1988 Peugeot Birraritz, 1984 Gitane Super Corsa, 1980s DeRosa, 1981 Bianchi Campione Del Mondo, 1992 Paramount OS, 1988 Colnago Technos, 1985 RalieghUSA SBDU Team Pro

Mentioned: 207 Post(s)
Tagged: 0 Thread(s)
Quoted: 1036 Post(s)
Liked 1,236 Times in 653 Posts
More Cottered Cranks

randyjawa my 1965 Swiss made Tigra has DURAX SPECIAL COURSE forged steel cranks with Simplex chainrings and a Campy cottered BB.




A few years back a LBS had this 1959 Paramount on consignment. It had these beautiful Stronglight cranks. Would have popped for it but the bike was too big for me.



A 1961 Paramount at the same shop...




verktyg
__________________
Don't believe everything you think! History is written by those who weren't there....

Chas. ;-)


Last edited by verktyg; 08-19-21 at 08:09 AM.
verktyg is offline  
Likes For verktyg:
Old 08-19-21, 07:43 AM
  #8  
1989Pre 
Standard Member
Thread Starter
 
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,216

Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1280 Post(s)
Liked 892 Times in 471 Posts
Hi Juvela.

The pins are new, but I tried to install them a couple of times, cranking them down as tightly as I normally do.
I'm sending a photo of the flats on the pins, and we can see, here, that there is a transverse slot that has been cut
(by the spindle flat edge?) When I press these new pins down, I see about 8mm of the top showing.
Yes, British, so 9.5mm.
1989Pre is offline  
Old 08-19-21, 07:51 AM
  #9  
1989Pre 
Standard Member
Thread Starter
 
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,216

Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1280 Post(s)
Liked 892 Times in 471 Posts
Thank you, Randy.

I am going to go through this process as soon as I hear back from Juvela and get his estimation of the markings on my cotter pins. It looks like I might have some filing to do, first.
1989Pre is offline  
Old 08-19-21, 07:53 AM
  #10  
1989Pre 
Standard Member
Thread Starter
 
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,216

Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1280 Post(s)
Liked 892 Times in 471 Posts
Verkytyg,

I had been using the same cotter pin set for about 5 years, and was fine until I dis-assembled the bike for painting and then re-assembled.
1989Pre is offline  
Old 08-19-21, 08:16 AM
  #11  
verktyg 
verktyg
 
verktyg's Avatar
 
Join Date: Jul 2006
Location: SF Bay Area
Posts: 4,035

Bikes: Current favorites: 1988 Peugeot Birraritz, 1984 Gitane Super Corsa, 1980s DeRosa, 1981 Bianchi Campione Del Mondo, 1992 Paramount OS, 1988 Colnago Technos, 1985 RalieghUSA SBDU Team Pro

Mentioned: 207 Post(s)
Tagged: 0 Thread(s)
Quoted: 1036 Post(s)
Liked 1,236 Times in 653 Posts
VAR 371 Cotter Vise

VAR 371 Cotter Vise for holding cotter pins while filing them to fit. Used them BITD when cotters didn't fit in the cranks properly. Also, the holes in cheap cranks sometimes got distorted.



verktyg
__________________
Don't believe everything you think! History is written by those who weren't there....

Chas. ;-)

verktyg is offline  
Old 08-19-21, 09:06 AM
  #12  
1989Pre 
Standard Member
Thread Starter
 
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,216

Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1280 Post(s)
Liked 892 Times in 471 Posts
Verkyg,

It is interesting that you mentioned "distorted mount holes" and "cheap cranks". I do not know if this is related to my cotter-pin woes, but the arm on this side in question is having a really tough time sliding onto the spindle. I can "get it on", but I have to twist and shout. A spare, identical arm, goes on with no effort. This is the crank I am using, a Raleigh-branded Nicklin:

Last edited by 1989Pre; 08-19-21 at 02:05 PM.
1989Pre is offline  
Old 08-19-21, 01:02 PM
  #13  
John E
feros ferio
 
John E's Avatar
 
Join Date: Jul 2000
Location: www.ci.encinitas.ca.us
Posts: 21,765

Bikes: 1959 Capo Modell Campagnolo; 1960 Capo Sieger (2); 1962 Carlton Franco Suisse; 1970 Peugeot UO-8; 1982 Bianchi Campione d'Italia; 1988 Schwinn Project KOM-10;

Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 1384 Post(s)
Liked 1,294 Times in 819 Posts
Originally Posted by verktyg
randyjawa those forged steel Stronglight cranks with alloy chainrings pictured above were handsome!
verktyg
Yup -- love the steel crank / SImplex adapter / aluminum rings look.




Agrati cranks with integral forged crank-and-spider. Aluminum Simplex rings, 58(!)-45.(I subsequently downsized to 49-45, which is more my style.)
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
John E is offline  
Old 08-20-21, 07:21 AM
  #14  
1989Pre 
Standard Member
Thread Starter
 
Join Date: Apr 2009
Location: Brunswick, Maine
Posts: 4,216

Bikes: 1948 P. Barnard & Son, 1962 Rudge Sports, 1963 Freddie Grubb Routier, 1980 Manufrance Hirondelle, 1983 F. Moser Sprint, 1989 Raleigh Technium Pre, 2001 Raleigh M80

Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1280 Post(s)
Liked 892 Times in 471 Posts
I found the issue today. It was actually the drive-side pin that was loose.., not the n.d.s. as suspected. I had looked at the end of the spindle to see if it was turning with the installed n.d.s. crank arm, and thought it was not, but, upon closer inspection, it was. Thank you for your helpful tips. They could help me in the future, if and when I encounter other cottered-crank situations. I would still like to know people's opinion on the lateral grooves on the new cotter pins. I'm sure there are threads on filing pin faces, so I'll look for one or two of those.

Last edited by 1989Pre; 08-21-21 at 07:37 AM.
1989Pre is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.