Cotter quandry
 

I'm struggling with a cotter problem. I picked up a beater Raleigh Rapide for free several months ago and as I always do, tore it down completely to clean up, polish, lube, etc... in other words, SOP. I've probably pulled a hundred cottered cranks and reinstalled with nary a problem - my handy dandy BikeSmith cotter press makes the job a snap.

Well, usually.

The problem is that I can't seem to get the dang cranks to stay lined up properly. I set the cotters and all is well, but when I go to ride the bike the cranks move in their seating. "OK," I thought. "I must have somehow used the wrong size cotter." So I swap 'em out for the next size up, but those won't fit. I compare to the cotters that came out and everything looks like a perfect match. I'm beginning to wonder if the spindle cotter slot is rounded off... sure doesn't look like it though.

Maybe I'm missing something entirely obvious. Any thoughts? Suggestions? Or should I just sit back, drink another Guinness, and quit worrying about it?

Well, that sounds annoying. Do you need to file down the larger size cotters, maybe?

Hi Azorch - What do you mean when you say the next size up won't fit? Cotters are normally filed to fit.



(lostarchitect beat me to it)

+100

It sounds strange and I've never installed a cotter, so I'm not a good source of information particular to this problem, but I have drank a LOT of beer over the years and that seems the best solution to a problem like this atmo.

I'm raising a glass of Stella Artois as we speak!

I should have clarified. Cotters come in three diameters, right? Using what appears to be the correct diameter fits without a problem - in fact, it fits very snugly. Where I usually have to file is on the angle, in order to have flat against flat - and that's where the problem seems to be for me. Even though everything feels tight, after I put a little torque on the pedals there is enough play for the crank arm to move - to rotate on the spindle slightly, keeping the pedals from being aligned on a perfect 180 degrees. They are slipping about two or three degrees - and that is both visually and physically discernable.

I've installed enough cotters that I figured, well heck, I must have filed off too much. But I've been through four sets of cotters now and I'm beginning to wonder what I'm doing wrong here - what is it I'm doing differently from every other time I've installed cotters.

Sorry to hear that.

Stella is very popular in UK, specially to cyclists it seems. I don't think I've tried it.



I personally would look over all the related parts very carefully. It sound like you have an damaged or excessively worn component.

Are the arms pretty tight with no cotters?
If you put a long bolt through the cotter hole is it tight in the bore and square to the arm?

It is a very mediocre beer, popular mainly because of advertising and because it's imported. Marginally better than domestic swill like Bud, but not much.

It sounds like to me that the diameter if the cotter is correct but angle on the face of the cotter is already too acute to warrant filing.

The Rapide was not made in Nottingham, so maybe the standard British relationship between spindle hole and cotter seat is different.
Just a theory.
I would paint the face of the cotter and let it dry. Then try reinstalling it to see where the spindle is contacting (or not).


('scuse me for veering off topic here - I like even mediocre beer. In fact, it's one of my favorite brands! ;))

+1 I bought Stella at Costco once and haven't bought it since. I like good beer. "Good people drink good beer," as Hunter S. Thompson once said.

My fault, I started it! ;)

I appreciate cheap beer, and am totally fine with it being mediocre. My issue with Stella is it TASTES cheap, but is fairly pricey. I'd be fine with it if it cost half as much.

I have a general question, which may help AZORCH in this instance. How do you go about ensuring the proper angle on filed cotter pin? The trial & error technique I've used is to press in the cotter, pull out, and look for any marks on the pin. If there are any marks, file that area down and repeat until no marks (i.e. flush fit). It's also been suggested to me that one can use a sharpie pen on the cotter surface to help see the marks. Randy Jawa made this nice write-up on how to use magnets to ensure the same angle on both cotter pins. I suspect the issue here may be that the angle of the filing is either not 100% flush, or not 100% flat. So, again, anyone wish to share tips or techniques for getting the proper angle on filed cotter pins?

P.s. Give me small-batch IPA over Stella any day.

This ^^^^. Are you absolutely certain, given the beater nature
of your project, that these are the original cranks ? Often cranks
get swapped out by guys who are not up to speed on differing
diameters and interchangeability.

Otherwise, since you are using new cotters and seem to understand
the process well, I got nothin'.

Are the cotters sticking through on the small end? Is the nut compressing the the cotter in snug or is it bottoming out on the top of the cotter?
Not that I care, I just needed an excuse to say that I really like Stella. Nice, smooth, refreshing without that imitation beer flavor that Coors products have.
Of course, local stuff is always nicer.

I just don't understand this angle talk. No matter what angle is on the cotter, the spindle will turn to match it. What's important is that both cotters have the same angle so the pedals will be at 180 degrees from each other. The reason for filing is to get the cotters to go in the correct amount. The trick is to get them even and perfectly flat for full contact with the spindle. I suspect that you are not pressing the cotters in tight enough. I use a box end wrench that's about a foot long.

well - not a cotter expert but i use the bikesmith tool on mine - and i usually have to go through the following process to get em to 'stay tight':
-install cotters
-ride
-tighten cotters
-ride
-tighten cotters
-done

beyond that - i would want pics to see the angle issue - and if the ride felt ok and the arms are without play - i would just continue riding and enjoy - as long as the 'angle' doesnt alter your pedaling mechanics to any major detriment to you physically

btw - did you try throwing the original cotters back on - or are they toast?

This is an interesting idea and I think I'll give it a shot.

@FTW: I haven't tried to check the holes with a bolt or rod...that's a real possibility I hadnt considered - that it may be slippage due to worn opening...I just automatically presumed it was the spindle, but this makes more sense. I'll check this tonight and post the result tomorrow. I may stick another crank on to see if the problem persists.

@GB: definitely in tightly enough...in fact I managed to get one in so far that I had to mushroom the sucker to get it out after still experiencing the same issue.

Thanks for the suggestions everyone. This bike is really just something I'm playing around with as a tweed rider for this spring. It'll work out or it won't...either way it will keep me busy over the holiday break.

We used to use something called Prussian Blue when assembling engines to check for surface contact. I have no clue if it still exists or where to buy it. But you put it on then put the parts together, if it rubbed off you had a high spot.

Aaron :)

On the cotter question, there are a few things you can check.

Spindle: are the two flats on the spindle parallel? Fnot, there’s your problem. Solution: new spindle.

Cotters: compare the two cotters. Are they the same diameter (this may not actually matter, but…)? Are the tapers the same (this is crucial!)? To check the tapers, hold the two cotters together, taper to taper, threads opposite one another; and measure the combined thickness at two or three places. If they vary, there’s your problem.

If spindle and cotters pass the above test, then you’re dealing with an installation problem. One of the cotters isn’t seating properly.

I suppose it’s possible that the hole in one of the crank arms is oblique, but I doubt it.

On the beer question, this is a matter of taste. Stella Artois is a perfectly acceptable rendition of the north German style of Pilsener, usually called Pils. If there is a difference between Becks and St Pauli and Heineken and Amstel and Molsens and Corona and Stella and a hundred others, I haven’t detected it. They are not my preferred type of beer, but even I'll admit they taste better than cat piss. If they are not to your taste, don’t order them. Try one of the Munich beers (but avoid the Pils, regardless of brand), Belgian beers, and English beers.

My bikes won't go together without beer...I know I have tried. ;) My favorite beers mostly come from New Belgium Brewery with Fat Tire Ale being the default (also the only one I can get regularly here in the boonies). After that I will try anything once. I do drink the occasional Guinness, Harp, Stella or whatever else is available.

Aaron :)

Magic Marker will also work for this in a pinch.

The problem has been identified.

http://farm8.staticflickr.com/7015/6...d907c22a_z.jpg

The photo doesn't show just how much of a lip there is on the spindle... enough that the cotter won't fit flat and snug against it without rotating and allowing the crank arm to slip backward and forward as you apply pressure when pedaling.

Well, crap. Guess I need to locate a replacement spindle or source a BB replacement. Can't imagine how I missed this (guess that goes to show what happens when you just presume everything is fine... I'll be inspecting things a bit more closely from this point forward.)

In the meantime, y'all enjoy your Stellas, Harps, etc. I'm sticking with Guinness.

Whoa AZORCH, that's quite some damage to the spindle. It's no wonder that your cranks weren't tightening up properly.

BTW, I like Guinness just fine. :D