Re: [CR]pinned joints

(Example: Framebuilders:Cecil Behringer)

From: <"">
Date: Thu, 9 Mar 2006 15:14:15 GMT
Subject: Re: [CR]pinned joints

Dennis and all,

I don't say much about pinning steeol frames, because it's an irrelevent factor on framebuilding as far as anything that matters goes. 99% of th e framebuilders I know SELECTIVLY use a few pins in a frame for the simp le reason is that is "cheap insurance" that a tube that has a potential to move during brazing (pinning a chainstay after it is tacked or before tacking will prevent a chainstay from slipping into the BB shell while brazing. All it takes is a simgle pin to insure this will never happen. End of story. Going beyond this doesn't make any sense to me, but tha't just me. Every framebuilder does it differently; and as long as everythi ng else is done properly there is no difference either way insofar as th e resulting frame goes. The quality of the frame DOES NOT depend on whea ther a frame is pinned or not. It depends on the skill and intentions of the framebuilder.

In the case of carbon and pins I would say they would be a potential saf ety net. A lugged frame could virtually never fail at the pin, assuming broper fitting, brazing, and cleanliness of the joint before assembly. T he junction could break, but it would likely have nothing to do with pin ning.

This pinning thing is a non issue, and yet the topic comes up constantly . What's up with that?? People call asking about my frames and upon ask if I pin my frames, as it it makes some kind of difference and that have the knowledge to interpert my answer. I'm REALLY tired of answering thi s question that doesn't mean a thing. Please don't ask me about pins and get it through your head that it is not one of the questions you can as k an experienced framebuilder without alerting them that you spend too m uch time at the computer and not enough time in the real world.

There's nothing wrong with pins, and in selective places I find them nec cessary, as do most framebuilders of lugged steel frames. There is no ne ed to make an issure of them beyond that. That's my opinion. Others MAY feel differently.

Brian Baylis La Mesa, CA Pins are our friends until they become our master.

-- Dennis Young wrote:

An extension of what Sergio mentions, is to say that pins are a

potential big pain in the as%), unless the joint is sound to begin

with. It is not particularly fun to have to go repair a joint with

pins in it.

Dennis Young Hotaka, Japan
> I don't think that "pins" would hurt a carbon frame or aluminum
> frame,
> providing that adequate bonding agent (glue in these cases) was
> present in the joint.
>> BUT (and this makes this message vintage pertinent & On Topic) those
>> pins really don't reinforce anything, in steel or any other frame
>> building material. They just keep the tubes in their appropriate
>> place
>> until the actual bonding (brazing, gluing or whatever) takes place.
>> After their job is done, the pins are redundant and hence Angel's
>> question asking if they were removed by builders after the building
>> process.
>> Dale Brown
> Caro Dale,
> I beg to differ here.
> Any joint that would tend to unglue cannot but profit by having an
> added mechanical impediment to that. The improvement depending on
> obvious details.
> Sergio
> Pisa
> P.s. Even a good cabinet maker adds wood pegs (no nails, please) to
> nicely fitted
> glued joints.