The secret of Trek's OCLV technology . . .

Greetings all,

Yesterday, I went into a bicycle shop that had a hands-on display of Trek's
OCLV frame technology.
I was able to pick up a frame section (the bottom bracket housing with short
stubs of frame tubes attached)
- it was intended to demonstrate Trek's carbon frame technology.
Trek calls it OCLV (Optimized Compaction, Low void technology).
And on their website, they make it out to be a company secret. In looking at
the demo part,
I was impressed by the rigidity and lightness.
And it caused me to wonder just how such a frame is actually fabricated.

I'm thinking it's just carbon and epoxy,
and that if one wishes to "optimize compaction" (remove voids) that it would
be necessary to
use a vacuum pump to draw bubbles out of the epoxy (Inside and outside
simultaneously?)
- possibly even while backing.

Anyway, I'm just wondering if any of you other guys have ever wondered about
the same thing,
and if anybody has any comments or thoughts on this carbon frame technology?

Thanks all,

- Stan Shankman

"Stan Shankman" wrote in message
si.com...
Anyway, I'm just wondering if any of you other guys have ever wondered
about
the same thing,
and if anybody has any comments or thoughts on this carbon frame
technology?

Well, I'm certainly not an expert in composites but I doubt Trek has
invented anything that hasn't been used in the aerospace industry for the
last 20 years. Perhaps new to biking, but not ground-breaking. I could be
wrong, that's for sure! No doubt though, they are strong frames, especially
for CF frames.

Cheers,

Scott..

stan- Anyway, I'm just wondering if any of you other guys have ever wondered
about
the same thing,
and if anybody has any comments or thoughts on this carbon frame technology?
BRBR

Any carbon fiber anything maker uses this 'pressed tightly together, w/o
bubbles' technology.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

In article , vecchio51
@aol.com says...
stan- Anyway, I'm just wondering if any of you other guys have ever wondered
about
the same thing,
and if anybody has any comments or thoughts on this carbon frame technology?
BRBR

Any carbon fiber anything maker uses this 'pressed tightly together, w/o
bubbles' technology.

Some still end up with tiny bubbles in the resin, though.

--
Remove the ns_ from if replying by e-mail (but keep posts in the
newsgroups if possible).

"David Kerber" wrote in message
...
In article , vecchio51
@aol.com says...
stan- Anyway, I'm just wondering if any of you other guys have ever
wondered
about
the same thing,
and if anybody has any comments or thoughts on this carbon frame
technology?
BRBR

Any carbon fiber anything maker uses this 'pressed tightly together, w/o
bubbles' technology.

Some still end up with tiny bubbles in the resin, though.

"Tiny bubbles... in the resin! Make me feel happy! Make me feel fine!"

David Kerber wrote:

In article , vecchio51
@aol.com says...

Any carbon fiber anything maker uses this 'pressed tightly together,
w/o bubbles' technology.

Some still end up with tiny bubbles in the resin, though.

I'd be surprised if they weren't using pre-preg -- no liquid resin, no bubbles.

In aerospace and marine use, modern carbon composites have shown better
reliability and durability than anything before. So for bike frames carbon is
fine, as long as the manufacturer is using the best techniques, with good
quality control. Fatigue performance for carbon parts can be exceptional.

However, it may be impossible to assess a carbon part's true condition, unlike
steel where one can look for cracks, dents, and buckling. Even aluminum can be
inspected visually. Carbon parts can have fatal flaws within, which can only be
detected by special equipment such as X-ray. They may appear perfect right
until they fail catastrophically. Broken parts can be nasty too, with extremely
sharp splinters and shards. So unless you *know* a carbon bike's history,
you're always taking a risk. If I crashed a bike with a carbon fork, I'd retire
it right then and there! With a steel bike, if it isn't bent, dented or
buckled, it's probably OK.

So that 5900 on eBay for half price might not be such a great deal. How do you
know a 200 LB man didn't ram a curb at 25 MPH, crashing onto a lawn, with no
visible damage to the bike except a collapsed front wheel? The wheel could be
replaced, and no one would be the wiser.

Matt O.

In article om,
says...
Greetings all,
Yesterday, I went into a bicycle shop that had a hands-on display of Trek's
OCLV frame technology.
I was able to pick up a frame section (the bottom bracket housing with short
stubs of frame tubes attached)
- it was intended to demonstrate Trek's carbon frame technology.
Trek calls it OCLV (Optimized Compaction, Low void technology).
And on their website, they make it out to be a company secret. In looking at
the demo part,
I was impressed by the rigidity and lightness.
And it caused me to wonder just how such a frame is actually fabricated.
I'm thinking it's just carbon and epoxy,
and that if one wishes to "optimize compaction" (remove voids) that it would
be necessary to
use a vacuum pump to draw bubbles out of the epoxy (Inside and outside
simultaneously?)
- possibly even while backing.
Anyway, I'm just wondering if any of you other guys have ever wondered about
the same thing,
and if anybody has any comments or thoughts on this carbon frame technology?

I'm pretty sure it is not a secret. I'm pretty sure I read somewhere that
they use a bladder to press the fibers into the mold and remove as much air
as possible. Since they use tubes and lugs, it is pretty easy to do.
--------------
Alex

"Alex Rodriguez" wrote in message
...
In article om,
says...
Greetings all,
Yesterday, I went into a bicycle shop that had a hands-on display of
Trek's
OCLV frame technology.
I was able to pick up a frame section (the bottom bracket housing with
short
stubs of frame tubes attached)
- it was intended to demonstrate Trek's carbon frame technology.
Trek calls it OCLV (Optimized Compaction, Low void technology).
And on their website, they make it out to be a company secret. In looking
at
the demo part,
I was impressed by the rigidity and lightness.
And it caused me to wonder just how such a frame is actually fabricated.
I'm thinking it's just carbon and epoxy,
and that if one wishes to "optimize compaction" (remove voids) that it
would
be necessary to
use a vacuum pump to draw bubbles out of the epoxy (Inside and outside
simultaneously?)
- possibly even while backing.
Anyway, I'm just wondering if any of you other guys have ever wondered
about
the same thing,
and if anybody has any comments or thoughts on this carbon frame
technology?

I'm pretty sure it is not a secret. I'm pretty sure I read somewhere that
they use a bladder to press the fibers into the mold and remove as much
air
as possible. Since they use tubes and lugs, it is pretty easy to do.
--------------
Alex


What we do down here at the Stanford Linear Accelerator Center, is put the
epoxy in a vacuum chamber and pump the bubbles out. This prevents voids.
-tom

David Kerber wrote in message ...
In article , vecchio51
@aol.com says...
stan- Anyway, I'm just wondering if any of you other guys have ever wondered
about
the same thing,
and if anybody has any comments or thoughts on this carbon frame technology?
BRBR

Any carbon fiber anything maker uses this 'pressed tightly together, w/o
bubbles' technology.

Some still end up with tiny bubbles in the resin, though.

Actually they are expected and planned for.. in aerospace it is all
spec'ed.
The only really notable thing about the treks is that the were able to
apply the lugged / bonded technology so well (1)... That made a
reasonable quality CF affordable for the first time.

(1)actually there were lots of failures in the first few years.. but
the company warrentied everyone I ever heard about.

"Stan Shankman" wrote in message isi.com...
Greetings all,

Yesterday, I went into a bicycle shop that had a hands-on display of Trek's
OCLV frame technology.
I was able to pick up a frame section (the bottom bracket housing with short
stubs of frame tubes attached)
- it was intended to demonstrate Trek's carbon frame technology.
Trek calls it OCLV (Optimized Compaction, Low void technology).
And on their website, they make it out to be a company secret. In looking at
the demo part,
I was impressed by the rigidity and lightness.
And it caused me to wonder just how such a frame is actually fabricated.


Even thought they have a monocoque appearance those bike are made as
lugs and tubes and assembled. It's a lot simpler to imagine making the
pieces this way than imagine making a whole frame in one mold.