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interesting carbon discussion(17 posts)

interesting carbon discussionDougSloan
Jul 10, 2002 1:56 PM
Some things I never knew:

Oscar Freire sprinted past Robbie McEwen and Erik Zabel to win stage two aboard the mount that has brought so many victories to Mapei and Rabobank. He was riding a Shimano

Dura-Ace equipped Colnago C40, the 2.5-pound frame that won Paris-Roubaix five times between 1995 and 2000. But it is not just another bonded carbon frame, since Colnago's construction methods C40 are unique and analogous to its method of constructing steel frames.

Integral to the C40 are one-piece molded, hand-finished carbon lugs that eliminate the bonding problems and weight of aluminum lugs and are stronger, stiffer, lighter (and costlier) than carbon lugs made of separate parts glued together. Most lugged carbon builders cut the tubes off straight and stick them into or over the lugs, but then the joint strength is entirely dependent on the lug's strength. Colnago instead miters each carbon tube precisely, just like the tubes of a welded titanium or aluminum frame (or lugged steel Colnago Master), so each tube fish-mouths around the next tube with complete contact between the tubes.

On a welded metal frame, it is obvious that there would be no strength to the joint if the tubes did not have this kind of complete contact to eliminate gaps in the weld, and it also makes a bike difference in a bonded carbon frame. The fully-contacting tubes work together and complement the lug's strength. In eight years of making C40s, Colnago claims to have never had a single failed glue bond. Colnago makes C40 lugs in 19 different angles so a wide variety of geometries are possible, and customers can order custom C40s. That's right - custom carbon frames! And if the airlines damage one of your tubes, Colnago can replace the tube and get your bike back on the road; you need not buy a whole new frame.

The development of the C40 is ongoing. The carbon is now lighter and stiffer, and the stays and bottom bracket have changed since the first of its Paris-Roubaix victories. Early models had aluminum bottom bracket sleeves like most carbon frames. Now, Colnago's titanium sleeve is knurled on the outside and has four teeth locking into notches in the carbon shell (see photo). It is far more expensive, but it is much better; titanium cannot corrode, and it has stronger threads and bonding.

Another refinement that is not to be confused with similar-looking features on other frames is the "B-Stay" carbon seatstay of the C40. At first glance, the B-Stay may look like the carbon wishbone seatstays currently in vogue on metal and carbon frames. But unlike one-size-fits- all wishbone whose upper end is simply cut off to fit the particular size of frame, the B-Stay is unique to each size and far more rigid (see photo).

Each leg of the B-Stay is narrow laterally and deep front-to-back for greater braking stiffness, and the whole structure resembles a tall inverted Y with an cross bridge for the brake, rather than simply mounting the brake at the wishbone crotch as others do. The bridge creates a reinforcing triangle out of the upper part of the stay, making the system much more rigid than a simple wishbone. Each size frame size has a different B-Stay, with a longer or shorter triangle above the bridge to optimize the stiffness. It would be much cheaper to have one stay and not machine a different B-Stay mold for each size, but it would not be as strong or stiff.

Colnago claims to be the world's only bicycle manufacturer to qualify for ISO9001, the international standard of quality assurance which was recently renamed Vision 2000 with new rules and certification procedures. By bringing its manufacturing process up to this standard, Colnago can trace each frame back to the smallest detail of material source, lot number, date of manufacture, and people who worked on it. If, for instance, a tubing supplier alerted the company to a defect in a shipment of tubes, Colnago could trace the exact frames the tubes were used on a
Jul 10, 2002 1:58 PM
... and recall only those specific ones.

"People see a price difference between our bikes and many of the others. But they can't see the internal details that make our bikes better and worth the price," comments Alessandro Colnago, Ernesto's nephew and marketing director. Maybe Oscar Freire can, though.

Any thoughts or comparisons to other carbon constructions methods?

Stop! I want one! Do they make customs ?n.m.koala
Jul 10, 2002 2:22 PM
customizing is easier onlugged CF frames? (nm)ColnagoFE
Jul 11, 2002 6:30 AM
Love my Kestrelwolfereeno
Jul 11, 2002 8:39 AM
I have a the 200sci and love it. For a little more $, the 300EMS is close to the weight of the C40. Both are all one piece. Although a Kestrel will never draw the same look of envy on the road!

Look makes a monocoque frame but I've yet to see one on the road. I only see the ones with the aluminum lugs.
Where are the photos in the OLN story? nmmmquest
Jul 10, 2002 2:38 PM
re: titanium does corrode......stik__boy
Jul 10, 2002 2:53 PM
just not at the same rate as aluminum......
re: titanium does corrode......paulw
Jul 10, 2002 5:59 PM
For all practicle purposes, titanium does not corrode. The only substances that will corrode titanium are certain acids like hydrofluoric.
0.08 inches per 10,000 years...PdxMark
Jul 10, 2002 6:28 PM
If you're a titanium drip shield having water drip on you in the Yucca Mountain National Nuclear Repository... or so they think.
re: interesting carbon discussionSantaCruz
Jul 10, 2002 3:12 PM
I'm not knowledgeable enough to debate all the pros/cons of various carbon manufacturing techniques. Calfee also makes custom carbon fiber frames. For anyone interested there is a "whitepaper" on carbon manufacturing at the Calfee website. Craig Calfee has been making carbon frames since the late 80's. Prices are lower than Colnago, but comes without peloton appeal.
Trek OCLV manufacturing questionPdxMark
Jul 10, 2002 3:34 PM
Some article, interview, or ad noted that Lance rides a stock OCLV because the tooling costs for each "frame" are $1 million. This has been bugging me because Treks use a simple lug and tube construction, right? If so, where are the tooling costs, unless they have to do with the costs for different bottom bracket lugs? If so, it sounds like Colnago paid those tooling costs up front to provide a wider range of sizes and sizing choices.

Great article. I'd like a size 58 C40, if anyone has an extra one.
Trek OCLV manufacturing questionstik__boy
Jul 10, 2002 3:47 PM
i read the same article and i dont believe that they stated an actual cost for the tooling besides "expensive". my g/f works at trek, knows the guy who did the interview..... and yes, lance and the posties ride stock bikes. its not really a "simple lug and tube construction".... each tube for each size frame is probably from a different machine. you couldnt have the same seat tube for each size frame.... so to simply make a custom sized frame wouldnt be at all very simple. now to say that lance doesnt have any input into what "stock" is is indeed a different story.
The C40 is a top-flight frame, but.........JohnG
Jul 10, 2002 4:39 PM
Don't mistake it for one nano-second, there are other frames that are of similar race worthiness. I.e. it ain't the frame that won all those races, it's the sponsored riders. Big congrats to Ernesto though, for building such a fine racing frame..... and oh do they look sweet too.

Still love my BSTAY CT1 and wouldn't trade it for anything..... even a C40.

Ti bottom bracket shell??C-40
Jul 10, 2002 5:55 PM
I'm not so sure about the accuracy of that claim. My 2002 Rabobank C-40 frame sure looked like it had an aluminum BB shell. I did notice the "teeth" on the face of the shell though.

Either way, it is a fine frame. I believe that the B-stay acutally improves the ride a bit, compared with the 2000 model non B-stay model.
Ti bottom bracket shell??DougSloan
Jul 11, 2002 7:00 AM
I thought it was aluminum, too. News to me.

I suppose we'd better get out the anti-seize.

And if the airlines damage one of your tubes...elviento
Jul 11, 2002 7:58 AM
"And if the airlines damage one of your tubes, Colnago can replace the tube and get your bike back on the road; you need not buy a whole new frame. "

I think the repair will probably take two years. I am still waiting for my stock C40 ordered on March 2nd.
And if the airlines damage one of your tubes...DougSloan
Jul 11, 2002 8:04 AM
If they airline damages my bike, they (or an insurer) are buying me a new bike.

You going through a local shop?

The Italians, including those at Trialtir (U.S. distributor), I'm told, have no interest in rushing anything. They get to it whenever. They told my shop they had "already shipped" mine three times.

No one should own only one bike. :-)