Columbus Muscle fork: Feedback Please

jim beam wrote in message om...
Carl Fogel wrote:

[snip]

I browsed a bit more and found this page describing the
Super Muscle Fork further on the same site:

http://www.framebuilding.com/what.htm

"In the fork column, Columbus has inserted Kevlar
layers, which through their ability to resist cuts
and abrasions, reduce the risk of cuts caused by the
clamps of the handlebar stem, which are particularly
sharp."

Again, I'm wary. Perhaps Kevlar resists cutting better
than plain carbon fiber, but I seem recall reading that
Kevlar is usually cut with ordinary scissors--its
virtues do not include any great resistance to cuts.

as nicely stated here;

http://plastics.about.com/library/weekly/aa050597.htm

kevlar is used to protect carbon composites against catastrophic
failure, but one of the only two failed carbon handlebars i've seen was
woven with kevlar, so who knows how this is supposed to work in practice.

while looking for that page, i got totally sidetracked by this:

http://www.ideafinder.com/history/inventors/kwolek.htm

do you have any tech-inclined daughters you want to inspire?

jb

Dear Jim,

A Google Groups search for kevlar and scissors
reassured me that I hadn't imagined reading
that Kevlar can be cut with scissors, but
casts doubt on the simplicity of the situation.

The web site that you suggested indicates special
ceramic scissors are used to cut Kevlar, yet a
Google Groups search for "kevlar" and "scissors"
shows posts and apparent controversy going back to
1993 about how hard the stuff is to cut:

Clinchers.. (Kevlar - a point to note).
.... As for the knife through the vest story, have you tried cutting
kevlar fiber?
It's really tough stuff and not easily cut with a sharp knife or
scissors. ...
rec.bicycles.tech - Aug 11, 2002 by Bill - View Thread (43 articles)

Recovering a seat
.... of staple. - Trim the excess with scissors where you can, then
with
a knife. It's a little tricky with Kevlar ! - Womens saddles ...
rec.bicycles.tech - Jul 1, 1998 by Andy Dingley - View Thread (7
articles)

experienced with composite materials?
.... Oh, and you'll need a good pair of scissors or knife
(professionals use ceramic
scissors and knives) to cut anything with kevlar in - and they'll
still blunt ...
rec.bicycles.tech - Sep 11, 1997 by Chris McSweeny - View Thread (3
articles)

Anyone used Specialized Armadillo?
.... The fibers were cut. Kevlar is tough but not invulnerable. It can
be cut with
sharp scissors, and the edges on broken glass are EXTREMELY sharp. ...
rec.bicycles.tech - Dec 28, 1996 by Ray Bowman - View Thread (18
articles)

Hollow (cylindrical) spokes?
.... I guess you have never played the ancient game of
"Paper-Scissor-Rock" If I
can cut Kevlar with household scissors, it isn't as hard as steel and
the ...
rec.bicycles.tech - Feb 4, 1995 by Jobst Brandt - View Thread (18
articles)

strength of kevlar
.... It has worked admirably. Kevlar can be cut with ordinary scissors
more easily than
fiber glass. Could someone elaborate on this, with some numbers? ....
....
rec.bicycles.tech - Jan 30, 1995 by Composites Lab - View Thread (3
articles)

Kevlar, Schmevlar
.... Kevlar. For instance, ordinary steel scissors cut Kevlar cloth
easily
as does glass even though it can stop bullets. Kevlar has ...
rec.bicycles.tech - Jul 24, 1993 by Jobst Brandt - View Thread (7
articles)

Possibly the Kevlar site is a little ambiguous?
That is, I'm not sure when I re-read it whether
they mean that Kevlar is difficult to cut or drill
at all (resistant) or difficult to cut or drill
neatly without fraying (messy).

"Finally, Kevlar is also very difficult to cut.
You will need special scissors for cutting dry
fabric or prepreg, and special drill bits for
drilling cured laminates. Cutting of cured
laminates without fraying is very difficult."

http://plastics.about.com/library/weekly/aa050597.htm

As for inspiring daughters with the story of
the inventor of Kevlar, all I have is a pair
of saucy sisters, both of whom need constant
stifling just to keep them (and their daughters)
in their place.

Carl Fogel

On 27 Dec 2003 10:13:12 -0800, (Carl Fogel)
wrote:

Possibly the Kevlar site is a little ambiguous?
That is, I'm not sure when I re-read it whether
they mean that Kevlar is difficult to cut or drill
at all (resistant) or difficult to cut or drill
neatly without fraying (messy).

Ordinary industrial grade scissors (not grade-school scissors) in good
shape will cut Kevlar ... for a little while.

For a under a hundred bucks you can experience it yourself:
http://www.aircraftspruce.com/ntoc.p...=cm&cat=kevlar
http://www.aircraftspruce.com/catalo...es/cutters.php

I once tried making skins for a disc wheel using Kevlar. I used
industrial grade scissors (the catalog said use for carbon fiber or
fiberglass). I didn't spring for the ceramic scissors (the same
catalog said use for Kevlar) because my early trials showed it was
easy to cut.

Well, after cutting out one circle the scissors were dull and it was
painfully slow progress! I bought and dulled several more industrial
grade scissors before I knuckled under and shelled out for the ceramic
ones.

I never did finish the disc. Never did much more with Kevlar, either.

dianne_1234 wrote in message . ..
On 27 Dec 2003 10:13:12 -0800, (Carl Fogel)
wrote:

Possibly the Kevlar site is a little ambiguous?
That is, I'm not sure when I re-read it whether
they mean that Kevlar is difficult to cut or drill
at all (resistant) or difficult to cut or drill
neatly without fraying (messy).

Ordinary industrial grade scissors (not grade-school scissors) in good
shape will cut Kevlar ... for a little while.

For a under a hundred bucks you can experience it yourself:
http://www.aircraftspruce.com/ntoc.p...=cm&cat=kevlar
http://www.aircraftspruce.com/catalo...es/cutters.php

I once tried making skins for a disc wheel using Kevlar. I used
industrial grade scissors (the catalog said use for carbon fiber or
fiberglass). I didn't spring for the ceramic scissors (the same
catalog said use for Kevlar) because my early trials showed it was
easy to cut.

Well, after cutting out one circle the scissors were dull and it was
painfully slow progress! I bought and dulled several more industrial
grade scissors before I knuckled under and shelled out for the ceramic
ones.

I never did finish the disc. Never did much more with Kevlar, either.

Dear Dianne,

As usual, you nail things down nicely.
So the stuff can be cut, but quickly dulls
even good steel blades suitable for cutting
carbon fiber--the Muscle Fork site is therefore
probably right in saying that Kevlar helps
resist cutting and I was wrong to be wary
of their claim.

Sorry about your snipped disc (and this
triple pun).

Thanks,

Carl Fogel