2/26/10 Update- The article
below was written back in 1996, 14 years ago. It's still relevant, but since
then we've seen the super-light ultra-performance carbon frame move into
moderate price levels. It no longer defines the extreme high end. That's
good news, but carries a warning. You cannot build a 2.5 pound carbon frame
as strong as a 3.5 pound frame. The tube walls are thinner, and when even
the highest-quality-possible construction (as found on Trek's OCLV product),
the can still easily damaged by forces not normally encountered when riding.
Blows to the side of a tube, for example, will likely cause them to crack.
Normal riding isn't an issue; the modern Trek OCLV will likely outlast
frames made of any other material. But making them so light, so comfortable,
so efficient... there is a trade-off in durability when abused or crashed.
We recommend a very thorough inspection of crashed frames of any material,
but carbon even more so, because it's difficult finding under-the-surface
damage. Riding a frame that has been crashed could cause unexpected failure
down the road. Please, if you have any doubts, bring such a bike in for
inspection. We cannot guarantee that it's perfect, but we may be able to
find an indication of trouble that others missed. --Mike--
(We
answer a question from somebody visiting our website. Even though this
dates back many years, it's still 100% relevant. --Mike--)
> From: Ralf X. Xxxx <ralf@xxxxxxx.net>
> To: Mike Jacoubowsky <MikeJ1@ix.netcom.com>
> Subject: Re: Purchasing a nice fast touring bike
> Date: Monday, September 23, 1996 8:54 PM
>
> Hi Mike
>
> Thank you for your very informative note....I really appreciate your
> thoughts. I have read about the wonderful qualities of Carbon Fiber but the
> caveat has always been that Carbon is "short term"...
>
> In a Road Bike Action article in May of 1995, they compared 5 different bike
> frames. Indication was that Carbon was best, but that QUOTE: "Carbon
> Fiber, in general, is not intended to last a lifetime. Buying a carbon
> fiber frame may be an every two year proposition. If that freaks you out,
> carbon fiber is not for you."
>
> Kind of scary considering buying a $1000 bike and only getting 2-3 years
> use.....Everything else about carbon fiber sounds wonderful.
>
> I stopped by the local shop today to look at the Trek 2120 and they didnt
> have any in stock, but the dealer talked about the 1997 Diamond Back road
> bike line of "Welded Carbon Fiber" coming out in 6 weeks. Any thoughts on
> that?
>
> Very confusing. I looked up the carbonframe on the internet and read up on
> their information page about carbon fiber and aluminum lugs being a
> potential problem....they use Titanium lugs....
>
> And I thought being a nice touring bike would be easy...LOLOL
>
> The TREK 2120 sounds wonderful...I don't plan on touring with much more than
> my "credit card" or a little cash!!
>
> Thanks again Mike....Carbon sounds perfect....especially if it does have a
> decent lifespan!!
>
> Ralf
OUR REPLY FOLLOWS-
Ralf:
In the real world, the TREK 3-tube carbon frames have had a phenomenal lifespan. That's
not to say that every once in awhile we don't have a problem...since we've probably sold
over a thousand (actually, we've easily sold over a thousand!), there's not much
that might be expected to happen that we wouldn't see. And I'd say we've probably seen
maybe 10 frames with a "dis-bond" problem, and these were from earlier times
when they made the lugs a bit differently and it was possible for too-tight a fit to
"squeegee" the epoxy out of the joint. But these are extremely rare and have nothing
to do with the theoretical problem of "ion exchange" that can occur between
carbon fiber and aluminum (resulting in decay of the aluminum structure). There are two
reasons that "ion exchange" is not a problem. First, TREK uses a thin fiberglass
layer on the inside of the tubes at their ends; this insulates the carbon material from
the aluminum. Second, the adhesive itself also performs this task.
The idea that a carbon frame (or at least a TREK carbon frame) will have you needing to
buy a new one every other year is interesting only in that people say the exact same thing
about the steel frames used by racers (which are generally replaced every year). A very
light steel frame carries a reasonable likelihood of failure somewhere in the neighborhood of
35-50,000 miles if it's flawless; this failure will most likely occur near the bottom of
the seat tube, on the side opposite the chainrings. Why? Because this is the most heavily
stressed area of your entire bicycle, and steel frames aren't over-built in the same
manner you can do with carbon simply because steel is rather heavy already. The other
common failure point is the dropout where it connects to the frame on the derailleur side,
although this is a bit less likely if everything about the frame is done correctly.
So what the heck am I saying? Basically that any frame designed to last in excess of
35,000 miles of normal riding (which the TREK carbon bikes are) either equals or surpasses
what is available in a steel frame. So, I just wouldn't worry about it and instead
concentrate on enjoying the ride!
Oh yeah, regarding the Diamondback...they've had limited success with that technology on
their mountain bikes. Interesting idea (bonding carbon to a steel tube so it can be
welded) but it fits into the "what's the point" category. Also keep in mind the
primary difference between TREK and nearly everyone else- TREK is, more than anything
else, a manufacturer. The engineer who designs your frame has an office literally within
100 feet of where they're actually built, and I think that makes a big difference. When
the designer can walk down the line and see his/her product take shape and take one out
and ride it in "real time"...well, it's just not the same when you send some
spec's oversees for a bid and get 2,000 of them in and notice that things aren't quite
like you planned.
Hope all this helps and didn't just make you even more confused!
Chainstay or Chew Stick? We've
told you how tough the OCLV Carbon frames
are, but we think a Chew Stick or Milkbone are better for your
dog. But, according to Cujo, TREK paint tastes just like
chicken!
PS: I've owned the following TREK road bikes since 1983:
750 Reynolds 531 steel racing frame (very nice bike, actually, and my
first TREK) 1500 Aluminum racing frameset (way-lighter than anything I'd previously
ridden, and its slightly longer wheelbase than the 750 mentioned above made it wonderfully
stable) 2300 3-tube carbon frameset (Who would have thought that a bike could be
so comfortable for 100 miles? My 1500 was very efficient, but the 2300
was smoother, livelier and just felt great when climbing) 5200OCLV full-carbon (This bike was part of
my riding routine for over six years, and would still be with me today were it not for it
finally succumbing to an incident on its very first ride when a couple of nasty front
downshifts tossed the chain into the frame and dug a whole clear through the
chainstay.
My early experience with Kestrels taught me how to make up a mixture of fiberglass
shards and epoxy to fill in the hole...it was supposed to be a temporary solution, but the
darn thing held up for six years! (Please note that filling in the
hole doesn't actually "repair" anything, but rather keeps things
from getting worse in the event the chain tries to attack the same area
again. It also keeps dirt and oil from working their way into the
tubing as well.) Incidentally, within a month after I got my frame
the problem was completely eliminated by placing an adhesive stainless-steel plate over
that part of the frame, as well as a "pickup ring" on the bottom bracket that
prevents the chain from becoming jammed in the first place). 5500OCLV full-carbon with Air-Rail OCLV fork.
Full-Dura-Ace (except for Ultegra cranks) 9-speed. This is the first time in my life
I've ever had absolute top-notch components, and I have to admit, it's very nice!
This bike survived a nasty
encounter with a car, with only the steel fork column failing. Y-Foil OCLV...this is my first really unconventional bike, with a design
that has no seat tube and a very tri-type look to it. Lots of fun to ride, and you can read all about it! 5900 OK, I'll admit it, in June 2001 I upgraded to the newest
OCLV, the 5900 (also known as Lance's "climbing bike").
Have to get around to writing a review of it sometime soon. Overall
it rides very similarly to the 5200/5500 frameset, but is just a bit
softer in the fork, and handles a bit more quickly (slightly less offset
to the fork). Madone 5.9SSL This is definitely the nicest bike I've had in the
stable. Comfortable, climbs & descends great, looks nice. Geometry
remains identical to my prior Treks, so it was love at first ride.
Nothing to complain about, and if you want to see how I introduced it to
the world, check out its first big ride up
Haleakala. Madone 6.9 2010- I had thought my 5.9SSL defined what a
bike could be. I was wrong. Almost exactly 4 years after getting my 5.9
SSL I made the jump to the latest version of Madone, complete with
ultra-wide drop-in-bearing bottom bracket (better for climbing and
sprinting) and the latest Shimano electric shifting (DI2). But what has
surprised me has been how this bike descends! Yes, it's more
comfortable, yes, it climbs better, yes, electric shifting is cool, but
what consistently blows me away has been how it feels on a dry descent
(I don't think any bike will give me great confidence descending Skyline
at 30mph in the rain, nor is it reasonable to expect that!). This bike
rocks. Plus it looks very cool. Natural carbon with lots of bright-green
decals.
Chain Reaction sells bicycles & accessories
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