dschad

Hi all,
I'm doing some research for a frame I'd like to finally build. I am figuring out brakes, and looking around for the braze-ons. I can find non-replaceable stud braze-ons, like this:

But I was surprised that I can't find only the female part which accepts the threaded studs, e.g., this:


Am I missing something? Should I roll my own here?

Note that I am specifically interested in removable because I am exploring the idea of two sets of mounts to support 26 and 700c wheels. Removing the upper studs would allow the brakes to work when moved to the lower position.

Thanks for any help.

Andrew R Stewart 

Some younger people would say your answer is disk brakes

Foe steel frames i know of no current removable boss bases. QBP/Problem Savers use to offer a repair boss kit that sort of could work but not at all what i would suggest. Know any one with a mill that likes after work beer? Not hard to draw out and make. Andy

Got lost in the football game and forgot to add- Back in the early 1980s Moots offered clamp on canti bosses so one could do what you ask for. Change from 700 road to 584 MtB. Andy

dschad

Yes, there is no problem that a good disc brake can't solve...however, I'm a glutton for punishment.

I suppose I will make my own then, assuming nothing pops up. I wonder if I could just modify existing full braze-ons - cut off the stud flush with the little plate and braze a threaded nut on the backside?

Thanks for the reply.
Don

bulgie 

Without doing any measurements or even looking at one, from memory, that sounds potentially do-able. The male thread on the available inserts is kinda large (M10 on Paragon's inserts, maybe everyones?), so there may not be enough room under a regular canti braze-on for the size of nut you'll need. But if you just hold an insert up to a braze-on, you can probably tell at a glance whether it's going to work. Some brands of canti braze-on are bigger than others, so maybe with the right braze-on?

Although you might just skip the canti braze-on, and weld the nut right to the stay or forkblade. Maybe with a gusset if it needs more offset (like if the stays are too wide for example), or just more strength/stiffness.

I like the idea. Please send us pics if you make it.

Trakhak

Back in the mid-'90's a teenaged customer asked how he could add cantilever posts to a chrome BMX fork. I said that the only way I knew that would preserve the chrome (i.e., that wouldn't involve welding) was to add Moots Mounts.

The next time I saw him, he told me he'd emailed Moots to buy a set and got a reply from Kent Ericksen, the founder of Moots Cycles. Kent had said it was years since he'd had them manufactured and would be glad to buy some back if we found a source (or so I remember the kid saying, anyway).

The reason I remember that incident as vividly as I do is that, in those early days of online communication, I was shocked that a customer could email a company directly and get a reply from the founder of the company, no less. The computer-literate kid thought nothing of doing so, of course.

dschad

I was wondering about the stud size, and I did come across titanium bosses (female) from Paragon Machine Works in CA. These are M10x1.5, so you can buy them.

For a general stud search, it seems like there is some variability, with most being M10 with 1.0 or 1.25 pitch. A couple M8 came up also.

I have an older stud, and I believe that by the time you finished filing the M10 nut to fit on the back of the stud, you would have two half-nuts.

Sounds like making something up will be the approach. I will post the results, but we are a ways away from that.

Thanks.
Don

unterhausen

Paragon doesn't have the frame part?

'02 nrs

https://www.amazon.com/Identiti-Clam.../dp/B007RP35CQ

rellis

Ceeway sells a few. All shown in the what's new section. https://ceeway.com/what.htm

guy153

There's a lot hidden in that section... including some flat caliper mounts I just made my own.

unterhausen

Yeah, lots of stuff on that page. Somehow makes me wonder if all of it is really new. Someone recently was asking about u-brake bosses, and they are on there.

dschad

They have both parts - the female boss for the frame and the removable stud. These are titanium (at least the boss is).

That is actually much better than I envisioned when I heard "clamp on", but those seem to be for a specific fork only.

Book-marked, thanks. They have a nice assortment of stuff it seems, although it looks like it is in the UK so not sure about shipping, etc.

Thanks all. I'll provide an update when I get there.

unterhausen

Shipping to the U.S. is not horrible from Ceeway. Probably more than you want to spend for a couple of bosses, but that's true from the U.S. as well nowadays.

Mark Beaver

I buy the majority of my lugs, bb’s, crowns, and braze-ons from Peter at Ceeway. His prices are excellent. Many things are 40% to 60% cheaper than from US suppliers, easily making up for the shipping charges.

dschad

Sounds good, I will keep this in mind. I would probably be ordering more than the couple of bosses once I put my list together, so it might make sense.

Thanks again.

Canaboo

I'm pretty sure Framebuilder Supply has them.

dschad

I started there, but didn't see them on the site which is why I started wondering if they were available. I did not contact them though.

unterhausen

I didn't see them there either.

TiHabanero

What is the purpose of a threaded in post? Outside of replacement in the event of damaging a post, which I have never seen, what is the advantage?

dschad

In my case I was exploring the idea of having two sets of posts on the stays/fork to support different wheel sizes. So one set for 559s and one for 622s (or 580s). It would be necessary to remove the unused studs for the brakes to operate.

Note that I haven't actually tried this, so I'm not 100% sure there is no interference, but it looks like it would work. I am also not really sure this is a good idea...

For the normal use-cases I think it is for ease of replacing damaged and/or worn posts. Don't know how common that is though.

Andrew R Stewart 

"For the normal use-cases I think it is for ease of replacing damaged and/or worn posts. Don't know how common that is though" dschad

While not numerous it has happened enough to have motivated Problem Solvers to offer a repair canti post kit, allowing for replacement of the post portion. I have had to install about 5 or6 over the years, less these days due to disk brakes taking over. Andy

bulgie 

The original reason was frames/forks in light alloy, where you want the bearing material of the post to be steel for durability.

Remind me, was the hoop over the tire on a "Mag 20" made of magnesium? or was it just the lower legs? Anyway the steel canti posts threaded into something too light and soft to make a good canti post.

TiHabanero

I get the non-steel frame need for threaded posts, however on a steel frame I have not seen a post that was damaged to the point of replacement. Must be some real aggressive riders out there!

Andrew R Stewart 

You might think so... I never kept track of this but seem to remember most of the bent/broken canti bosses I have dealt with have been on more recreational or commuter type bikes, all being steel. I long ago figured out ignorance is just as damaging as incidents can be Andy

unterhausen

I suspect that people that rode their 26" mtb well beyond its capabilities would bend a canti post occasionally. I know a couple of people that ride like that, it's amazing they have survived.
The LBS has a whole collection of canti posts. Probably could get rid of them at this point. Every once in a while someone will bring in a high-end mountain bike from the canti era, but it's almost always being retired. But if it's a Grove, then the LBS acquires it and puts it in the museum.