I got new cotters, and they are in tight, and the nuts on the threaded end are engaged (one side fully, the other side caught only 2 or 3 threads, but did snug-up). I have 10mm of the non-threaded end visible on each crank. Should I go ahead and sand/file a little off the diagonal face of the pin, to get it to push farther through before I put the nut on? 10mm looks like too much visible.

-----

you've got an asymmetry somewhere

the pins may not be identical

the crank arms may not be a match

when the difference is in the pins then the usual procedure is to file the cut on the pin with the lighter cut

another thing you can check when the pins are in this state is the opposition of the crank arms -
they may not be a symmetric one hundred eighty degrees...

---

here is one that will sound silly at first -

sometimes if a wedgebolt has worked loose in the past the combination of play and the torque of pedaling can gall up the walls of the wedgebolt hole in the head of the arm

rare, but takes only a moment to check for this


-----

A picture would help.

I like exposed threads after all is said and done.

Frejus 40 by iabisdb, on Flickr

Nice crank!

I sanded one pin down and they are now about equal, with 10mm of the non threaded side sticking out. They're tight, so I'll just leave it. A new camera is on the way, my old one is broken.

well look at….it’s a nice looking crankset.



I think it’s from the Marines all that hot Sun at Parris Island and the flightline in Yuma.

Cotter pins and social media, nothing good can come of it when these two things are brought together.

Except maybe a picture of a "nice crank" showing what a properly installed cotter looks like. Well done iab. And I agree.. nice crank.

So Bianchigirl was actually replying to iab, and not me? Maybe it is best to hit "quote" when one wants to reply to a specific comment, instead of it appearing to be directed to the O.P. What is this, just laziness? Now, I'm tempted to feel like I over-reacted, but can we agree on this one guideline?

Exactly. iab has stated that some thread should be showing. This is my belief and experience, as well. So, here we get to see my original post again:

"I got new cotters, and they are in tight, and the nuts on the threaded end are engaged (one side fully, the other side caught only 2 or 3 threads, but did snug-up). I have 10mm of the non-threaded end visible on each crank. Should I go ahead and sand/file a little off the diagonal face of the pin, to get it to push farther through before I put the nut on? 10mm looks like too much visible."
There are no threads visible on either pin. The threaded section comes about flush with the outside of the nut.

Anyone who can give me a direct answer is welcome.

Well, to get pedantic.

Bianchigirl's reply was directly after my post, and quite frankly, mine is a nice crank. A bit of thread drift, yes, but so it goes.

And what I wrote concerning cotters is a preference, it is neither right or wrong. I also have about 10mm of cotter showing but plenty of threads too. There are crank and cotter variables that can change the answer, that is why I requested a picture. juvela used words to make the same point. Bottom line, if the crank is secure, the job was done right. Carryon.

you mean like not taking the time to post photos of your cotter pins?

Yeah, it's just like not bothering to read in that i don't have a camera right now. Dope.

Old school cranks typically had a 10mm or so drive side off set and yes one did need to file the pins to get a good fit so you should be fine if stuff is basically strait and tight You can have a 5mm or so difference from perfect with no real issues.

This is what my cotter pin installations look like, but the two or three 1950ies bikes i got, who were built contemporary, had almost no length of pin or thread sticking out. It saves a lot of trouser legs, too

Great job for freehand likely done without a cotter press pin setter and alignment tools.

This thread is confusing since 1989Pre is on my Ignore list, but I see from quotes that he called @Bianchigirll a scatological insult word, and then in another post called her lazy. Then called someone else a dope. After coming here asking for advice. Why do people reply to such nastiness?

On a few bikes, after filing the cotters to get the amount of thread I like sticking out (just a bit past the nut, ideally ~1 thread), I took the pins out and cut them short on the unthreaded end, so just a few mm sticks out on that side. Less trouser-catching, and light weight!!!

But then the cut can rust, so I keep them covered in grime.

so you expect us to guess what the problem is with no photos and a unintelligent description? no, you are the dope