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Old July 11th 18, 11:46 PM posted to rec.bicycles.tech
John B. Slocomb
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Posts: 547
Default drill/tap in frames

On Wed, 11 Jul 2018 09:42:08 -0700, Jeff Liebermann
wrote:

On Tue, 10 Jul 2018 20:41:08 -0700, John B. Slocomb
wrote:

On Sat, 07 Jul 2018 12:33:38 -0700, Jeff Liebermann
wrote:

On Sat, 7 Jul 2018 11:06:52 -0400, Frank Krygowski
wrote:

This group has debated Rivnuts extensively. One poster claims nobody
should install a Rivnut unless he has access to a complete machine shop.
Others with more experience have said that the installation is easy for
anyone with normal mechanical skills.

That would be SMS (Steven Scharf) on one of his web pages:
http://nordicgroup.us/cageboss/

Since I've made a mess with all the available technologies, Rivnuts
(steel and aluminum), brazing (steel), TIG (aluminum), and epoxy glue
(plastic boss on aluminum), I'll remain neutral on the matter.

Hint: Use steel Rivnuts on steel frames, aluminum Rivnuts on aluminum
frame, and plastic straps or clamps on CF (carbon fiber).


One can only suppose that those "dumb asses: that manufacture rivnuts
deliberately make their product in a number of materials :-)


I'm not sure about the deliberate part, but yes, one can buy them in
steel or aluminum. I couldn't find any plastic or carbon fiber
rivnuts.

And, it might be added that not knowing what you are doing is not
limited to bicycle maintenence :-)


True. If those expounding on bicycle technology by various electronic
means really knew what they were doing, they would be riding instead
of pounding on the keyboard. If you really want to know how things
work, find someone that is actually doing the work and interrogate
them for the information you need and don't bother reading books,
manufacturers literature, magazines, forums, and newsgroups. The only
downside is that those who really know, tend to be inarticulate and
have difficulties explaining complex concepts, like which way to
tighten a right handed bolt. However, persistence, intimidation, and
perhaps bribery will eventually produce the required answer from a
real expert.

As I mentioned, I have successfully trashed most everything I've tried
to do with Rivnuts on bicycles, and therefore have no opinion on the
matter. However, it might be interesting to try a simple test. I
could probably finance the test by taking bets on the outcome.

Take two identical lengths of steel bicycle tubing. Install a Rivnut
in only one tube at midpoint. Clamp one end in a pipe vise. Pull on
the other end with a Come-Along perpendicular to the tubing. Measure
the force with a load cell. Draw a graph to show when the tubing went
plastic and eventually buckled. Compare results between the tubing
with and without the Rivnut. That should settle the debate whether
Rivnuts are detrimental to frame and stay strength.



(Big Smile) I know a bike builder who accidentally did just that, with
out the rivnut being installed - bending the curve into the front fork
blades with a 5 foot bar :-)

But as an aside, anything will break given sufficient force applied
which doesn't prove much of anything.
--

Cheers,

John B.
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