Well no hoarding, strictly speaking -- just need one.

Went to ride the Palo Alto recently and noticed the acorn nut on the rear NR brake was gone (to paraphrase the Brit Car folks "The parts falling off this bike are of the finest Italian quality" -- sheesh, this wouldn't have happened with Mafacs!), and, although the brake works fine for the moment, I guess I should replace it, lest I'm tempted to grip the center shaft with one of those miniture pairs of Vice Grips and be done with it.

OK, is there a nice little on-line small parts vendor, or do I have to cruise CL and eBay forever hoping for the best? Er, I guess it does not have to be brev-camp, if anyone knows the correct size and a place that sells acorn nots in lots of less than 1000.

Hmm, it occurs to me that, if I replace the entire brake set with something else (my favorite non-Mafac set-up has been Weinmann 500's but with Universal levers), then I could move the Campys over to my wife's newly-acquired Windsor (the Her Jewel topic finally has photos up) to make it fully Campy.

Did you try loose screws? https://www.loosescrews.com/

they are not exactly the same thing, nor as pretty but I just get SS ones at True Value.

Wow, I thought they went out of business a gazillion years ago, I recall a letter from them in pre-internet days? Well, I bookmarked it, thanks -- BUT I looked all over that site, did not find the acorn nut. Anywhere else?

Might have to. Is there a way to know other than trial and error for the thread size?

Nope, I just ordered a box of bearings and some other random stuff from them!

The only ones I see at loose screws are 4mm size: https://www.loosescrews.com/index.cgi...d=444893419313

But it might be better to go to the hardware store and find out if they have something that works. It's not really a part that needs to look super great, I suppose.

I'll e-mail them and ask if they know. I guess, if I had to, I could disconnect the brake and drag it to Home Depot (I think the last traditional hardware store in the region closed a few months back ) or simply roll the whole bike in.

Home Depot has no metric sized nuts. Ace Hardware usually does. Of course, your local bike shop probably has a drawer full.

Support your LBS.

Could also try an auto parts place.

Oh! I se the "contact us" at Loose Screws specifically cites "Do Not Ask Technical Questions" so there goes that, will end up at hardware store -- wherever that may be. Anyone have some small metal stamps so I can put a little "C" on it?

Sheesh, I thought this would be easy; just wait until I ask for a cover plate that fell off one of my Simplex 543 derailleurs!

I don't think the acorn nuts have any markings on them. The radius of the dome may differ from a modern, but that's about it.

PM me to remind me to look & see if I have one.

Bike co-ops usually have them by the box full, and sell them by the coin.

the threads are a standard M6 or 6mm

Most mechanics have thread gauges.

M6 bolts normally have 1mm thread pitch.

Thanks, that should get me close.

Google the words fasteners and your city's name. I tried fasteners Thunder Bay and got several local hits. Hope this is a help.

I also vote for LBS, but if that isn't doable for whatever reason, simply take the nut from the other brake with you when you go to find another one. Most places have those little test boards with different size bolts sticking out of them that you can test fit it on to find the correct size/threading.

How many do you need? I must have a few in my junque pile.

This post is pure heresy!

You are hereby required to get the proper replacement parts installed in the next 30 days. A complete and thorough maintenance cycle on all moving parts is also required, as Campagnolo parts do not just "fall off", they are lost due to owner neglect and negligence.

If you fail to comply, you will be required to remove all vintage Campagnolo parts from your bicycle. You are barred from using or owning Campagnolo parts forevermore.

ONE! And thanks.

It took until Post 20 for someone to say that?