kanawa 

are nutted Nuovo Record brakes "convertible" to recessed by just replacing nut with a recessed allen? Thanks.

Kabuki12

The shafts are different lengths and the threads are closer to the brake itself. The recessed nuts need to get in closer to tighten.

tiger1964 

I need to go look at a bike I did this to; I seem to recall I took a "recessed nut" and bored a hole through it to make it into a slip-through bushing, then used a regular nut.

repechage

Back when calipers lagged behind the frames, the method was- rear pivot bolt to front- cut front and use a die ( with handle, no cheating)
to thread the soon to be rear brake pivot bolt to length.

different rear bridges require different lengths.
to obtain the clean threading you need I have found it best to flip the die and carefully work the base of the pivot to a uniform thread.

Or, post in the for sale or trade thread a willingness to trade a nutted fixation front pivot for a recessed rear. They are not making any more of them...you might make someone’s day and save your M6x1 die - chrome wears them out fast.

Steel Charlie

Campy, and everybody else far as I know, made the same, one length rear bolt for recessed nuts - about 14mm overall and 10mm of threads. The front was 28mm and 18mm of threads. The nuts were different grip lengths with the front +/-15mm and the rear +/-9mm
measurements from NIB 1987 SR's

a converted non-recessed bridge may take something different but I never came across any recessed nut bridge that wouldn't take any recessed nut brake. YMMV of course

pcb 

That is an interesting approach that never entered my mind. Cool!

There were hard-ish plastic bushings one could purchase to basically do the same thing. I remember Rivendell used to carry them. Maybe still do? Haven't looked for a long time. Likely a standard plastic bushing of suitable size could be gotten from a good hardware store, or McMaster-Carr.

Replacing the front pivot bolt with a proper rear recessed one has already been mentioned. Might also be worth mentioning that since the Campy sidepulls were one of the most-copied bicycle components ever, there are a whole bunch of Dia-Compe and Suntour sidepull pivot bolts that are completely interchangeable. Many have no brand name stamping, so although it's not a historically accurate approach, it doesn't necessarily shout "NON-ORIGINAL REPLACEMENT HERE!!!!" at you.

tiger1964 

Pretty sure I posted a topic here on it, perhaps two years ago. Plastic, if you don't mind plastic on one's BRAKES, would be easier. I have a memory of it being difficult to bore the hole out through the very hard steel recessed nut. I think I somewhere got a pack of various lengths, and needed to cut down the length before boring.

oneclick 

There's a potential small issue with this approach.

The rear faces of some fork crowns are curved enough that a spacer with a matching curve is (/should often be) used. If you don't use this spacer the flange of the bored-out "recessed nut" will only bear on the fork face at 12 and 6 o'clock, which cannot be good.

So drill the curved spacer and pass the nut through that as well.

pcb 

Although I don't usually like putting the words "plastic" and "brakes" in the same sentence, when the nut/washer is tightened against the bushing/crown only the flange is being compressed. And using a good washer under the nut spreads out that force pretty evenly. And the flange could crack without lessening the clamping force. You'd have to have pieces crack and leave to give the washer room to loosen. And I've never had one break on me.

It did strike me as likely difficult to drill through a steel recessed nut. If anybody wants to go this route, there are aluminum alloy recessed nuts available, which should be easier to hollow out.

Maybe also worth mentioning that some recessed nuts have larger outer flanges/faces than others, with the larger-diameter flanges likely providing better clamping force---or at least more widely distributed.

pcb 

Very good point! My brain wants to tell me that most of the recessed-mount fork crowns I've played with are either relatively flat on the back, or have a raised flattish section surrounding the pivot bolt opening. But my brain also wants to tell me all kinds of things that aren't true, like as a yout' I was immortal, so I wouldn't be surprised to learn there are recessed-mount fork crowns with very curvy behinds.

tiger1964 

Interesting, and I took a look at mine. There is no curved washer/spacer, but the fork crown has little curvature; that said, I could probably get the point of an X-Acto knife in between at 3 o'clock and 9 o'clock, I probably have good contact between 10 and 2 and between 4 and 8. A thicker washer and a minute with a Dremel would provide better contact. Thanks for pointing this out! Presuming I can be convinced to ever hit the brakes anyway...

JohnDThompson 

Curved crowns that are intended to be used with Allen-head mounting bolts will have a flat counterbore at the mounting hole for the Allen head piece to fit.

Yes, if you're retrofitting an Allen head mount, that is the best approach. But then it's not really "recessed" because the Allen head will stand proud of the washer.