Is there a wrench for this?
 

This pic is of the seatpost bolt nut on my Univega Super Speciale. I've never been really successful holding it in place while snugging up the bolt. I've tried screwdrivers, nickels, chainring bolt wrenches. Nothing seems to work well. Of course, my seatpost slipped while out in the "wilds" of Michigan just now (a bit south of South Haven). I've done what I can to tighten it up, but suspect it will slip again (yes, I have the proper size seatpost).

Is there a wrench for this beastie? If not, I think something like JB Weld will hold it in place. If I was going to get the frame painted, I'd probably just have it brazed in place.

https://cimg1.ibsrv.net/gimg/bikefor...a3767b295b.jpg

I would seek a different bolt/nut is there something unique or proprietary about it?

That is an example of form over function (I am being charitable here).
Best replaced entirely, with something that will let you get a good grip on both ends.

You might find a bog-standard seatpost-bolt nut of the recessed variety will fit in the frame socket; if so file off the tang and cut it carefully to length, such that it bears on the internal flange of the frame-socket, not on the rim (leave a little gap there to allow for wear).

Can’t you just get a new binder bolt, pretty cheap for cr-mo one on Amazon, or you could break the bank and get a Campy, either would look way better, and stop your seat post from slipping. If that were my bike, just the look of that thing, as it is, would drive me nuts.
Tim


https://cimg4.ibsrv.net/gimg/bikefor...55ccbb51c.jpeg

Don't mess with nickels, step up to a quarter. 😋😁

almost looks like the back part of a chainring bolt, maybe try a chainring wrench

no idea about the wrench. Maybe find a suitable screwdriver and grind a notch in the middle so it could fit?
The suggestions to replace the bolt and nut with something more user friendly seem like a good idea too.

I'm really just here to suggest bearing retainer compound instead of JB Weld (even though I'm about to use JB Weld for a small job myself).
I suspect bearing retainer compound might provide enough grip to do the job while still permitting removal of the nut in the future.
Something like this perhaps?

It might be worth perusing the websites for the companies making threadlocking compounds, bearing retainer compounds, etc. They sometimes have charts or tools to identify the best product for a particular task.

Steve in Peoria

That "nut" is toast. I would replace with the double allen like above. If you're adamant about getting a matching replacement (assuming it's original) Ace hardware (if local) may have it. Grainger's, McMasters and other online sources certainly will have it. It's just a round slotted nut.

I just remembered something, some bolt heads have a weird little tang, that sits in a notch, which keeps it from spinning. See if flipping it around might reveal that to you. 🤔

Thanks for the suggestions, even the more expensive monetary one. A nickel was the largest coin I had in my pocket at the time. ;)

I was literally on my ride when I wrote (still am, at a coffee stop in South Haven), so hopefully you'll understand that details were kept to a minimum. The bolt and nut are meant for the seatpost binder. I doubt a Campy style binder bolt will work (though I have a couple to try back at home). The bolt itself is your normal diameter thing, while the Campy thing is much larger diameter. Frame surgery not gonna happen.

While I ride back to the beach house I'll leave you with a puzzle too solve. I think I know why it happened, but you get to speculate wildly. I test rode the bike before coming up. Everything was fine. When I set out on my ride this morning I heard this horrible grinding from down by the bottom bracket. "Oh no, that doesn't sound good at all!" I stopped and investigated a little. If I turned the crank, it made the sound once per cycle, no matter if I spun the crank forward or backward. I peeked they the bb shell window and was reminded that I have a Tange Seiki sealed bottom bracket, so that wasn't likely to be the cause. It took a minute to figure out what the problem was. The fix was pretty trivial.

So, two questions for the assembled experts. One, what was the problem? Two, what caused it? Hint: I use a Saris Bones rack. The first to answer both questions correctly will get a small bike-related gift in the mail. :)

The problem was, you were able to hear this "alleged" noise, and it was caused by you taking off your heavy winter hat too soon. 😋😁😉

I dunno, I keep thinking it was your pants leg hitting something, but you were probably wearing shorts. 🤔

Strap from the Bones rack left hanging on the frame somewhere, hitting one of the crank arms as it goes by?

Is that just a stripped out allen bolt that someone cut a screwdriver slot into?

It probably has something to do with the secondary strappy thing that stabilizes back and forth I presume? YOu forgot to detach it and it stayed on the seat-tube where it interferes.

Or the strap moved the front derailleur enough the pedal hits it.

Good guesses, but nope.

+1
https://cimg0.ibsrv.net/gimg/bikefor...07d8ca36c5.png

You forgot to take the bike off the rack...

"Break" being the operative word, regarding Campy seatpost bolts. They make them out of glass.

Yeah I thought those nuts had a nub on the backside. It may be intended to fit on the Left side of the bike ('non-drive side" for those who have trouble with right-left)

I have some nuts that are a plain cylinder with M6 thread and a 6 mm allen socket. They came with Gipiemme brake bridges, for recessed brake mounting. Not the normal "top hat" shape of brake nut though, just the cylinder without the flange. Oh right, here's a picture:

https://cimg9.ibsrv.net/gimg/bikefor...1b816acb8e.jpg

They are somewhat precious to me but I will sell one for $10 shipped in the US, if that'll help you. It'll leave me with one brake bridge without a nut, but I'm unlikely to use that bridge anyway...

One disadvantage of this type is the bolt needs to be just the right length. Too long and it fills up the allen socket; too short and you don't have enough threads engaged. A stainless bolt can be trimmed to just the right length without the cut end rusting, if that matters to you.

Dimensions 10 mm diameter, 10 mm long, 6 mm length of threads. Chrome plated.

Mark B in Seattle

He mentioned he tried a chainring bolt wrench in his very first post.

Oops. My bad.

There are different sizes of chainring NUT wrenches (you use an allen wrench on the bolt....), but I think they're still all too large for the OP's purpose.

Burning question - is there a notch in the hole on the NDS ear for a conventional binder nut with a tab to lock into? (Or on the DS ear, for that matter?)

I do not consider myself an expert but here is what I think might have happened: You took your bike off the bike rack. You did not notice that the rack had somehow pulled the front derailleur-shifter cable off from the metal cable guides located on top of the bb shell. The fd cable is now hanging loosely. You tried to ride the bike but the crank caught the fd cable and wound it around the bb causing the fd to shift on it's own or become mis-aligned that it interferes with the crank causing the grinding noise.

https://cimg8.ibsrv.net/gimg/bikefor...d5be38932.jpeg
https://www.acehardware.com/departme...E&gclsrc=aw.ds

Get one of these and grind down the sides to fit if necessary, short, stubby and stout

Clean up that slotted nut and do whatever it takes to keep it in use, no way I would replace it unless I absolutely had too. ;)

I used a nut like that on my Gran Premio Univega, I eventually switched to a 5mm Allen nut from a V-brake brakepads.