What is the difference between new carbon and old carbon?
Posted: Fri Mar 19, 2004 1:30 pm
Incomplete Pete wrote:It's made diffently - as I understand it the "new" carbon as you can see on the Record cranks and is used on all Trek OCLVs, is made from a paste and then baked, this is why you get the smudgy affect.
Where as the old style of carbon is simply layered up, bit of by bit and thus looks pretty!
Superlite wrote:The "new" carbon is unidirectional carbon fibers. It is a process that uses carbon flakes, and extremely high pressure bonding. The flakes are bonded together in random directions and create a super strong structure.
The "old" Is just woven carbon fibers. Different plys, different layers, each in a direction to strengthen the product.
I was reading about the new Campy carbon cranks (both Record and Chorus):
"These new products have been developed using Unidirectional Carbon Fibre, a new composite material technology that originated in the aerospace industry." For 2004, this replaces Campagnolo's previous 90-degree carbon fiber lay-up for cranksets. This new technology distributes carbon fiber in all directions to produce mechanical resistance in any direction.
Furthermore, Campagnolo's Unidirectional Carbon Fiber has been placed to further enhance the already outstanding performance of the Record and Chorus cranksets."
Is this carbon fiber that much different than the "traditional" carbon used on Giant bikes or even my Easton monkey light carbon riser bars?
I also thought about another friend who just bought a new 2004 Trek carbon bike with a "nude" finish...in other words, you see the carbon instead of paint.
The carbon on the Trek looks unidirectional like the carbon on the new Campy cranks. So....finally...the question......Is this "new" unidirectional carbon the wave of the future or just an alternative? I am thinking of buying a carbon frame this year, either Giant or Trek and I am wondering if there are advantages or tradeoffs that I am not really considering.
Answer from Trek:
We believe that Mike may have accidentally mis-worded his question. The consumer stated that the new carbon fiber (that Campagnolo is using) is a "unidirectional" carbon fiber, when in reality it is a "multidirectional" carbon fiber material (www.Campagnolo.com).
In 2000, Trek was the first company in the bike industry to introduce a frame component using multi-directional carbon fiber. This new material, called OCLV MC (Optimum Compaction Low Void Molding Compound), was used for the rocker links on the Fuel 98 and 100 suspension frames. OCLV MC is a proprietary material that uses the same carbon fiber as traditional unidirectional carbon fiber, but rather than having the fibers all oriented in one direction, it has shorter (50 mm long) randomly oriented bundles of carbon fiber. The randomly oriented fiber bundles cause this material to have nearly identical mechanical properties in all directions.
While traditional carbon fiber works well in many tubing applications
(where a high strength to weight ratio) is desirable, due to molding difficulties, it doesn't always work well for molding parts with ribs, tight radii, counter bore holes, and other complex 3D features. OCLV MC however, while still having a high strength to weight ratio, works very well for molding parts that are not hollow (like tubes) and that have complex 3D features.
At Trek, we look at OCLV MC as a material that compliments our traditional OCLV unidirectional material. It will not replace it. Both materials will always have their place in our product line-up. Regarding the question of "Trek vs. Giant", both companies have similar materials available to them so the main difference is the process used to create the bike frame. Trek uses a patented process called OCLV (Optimum Compaction Low Void) to produce our carbon frames. The OCLV process allows us to produce composite frames that are virtually free of voids (which weaken the bond) in the composite laminate and that exceed aerospace standards. We believe this process sets us apart from our competition through the high quality parts that it produces.
Trek carbon engineer
Record™ Carbon Crankset
The carbon-fiber Record crankset outclasses itself.
A new technology of composite materials that was recently introduced to the aerospace industry is now used in the new Record crankset: Multidirectional Carbon Fiber. This new technology distributes the carbon fiber in all directions to produce mechanical resistance in any direction. In addition, if it is not sufficient, Unidirectional Carbon Fiber has been judiciously positioned to further enhance the already outstanding mechanical performance of the Record crankset.
The results are amazing. Last year’s Record crankset was vastly superior to those of our competitors and this new one outclasses itself:
- Innovative design for maximum stiffness
- weighs just 500 g
- greater resistance to static load
- greater resistance to fatigue
- greater resistance to torsion
The absolutely innovative result is that this new technology enables an industrial process to be created that eliminates the erratic results and performance of a manual process. Arranging the carbon fiber in the cranksets was until now an exclusively craft activity and because of this results and performance within the same component could differ widely. But by industrializing the process we have finally been able to obtain components that are all of the same impeccable quality.
The chainrings with their ultra-drive geometry have been given a special new treatment that reduces attrition with the chain and improves resistance to wear.
Another important aspect of this new carbon-fiber crankset that should be emphasized is the Q factor: it is the same as for the aluminum version.
Xterra Racer wrote:Nick....since your a carbon builder, can you give some of us less tech informed board members a quick tutorial on differences in carbon building (OCLV, Uni, Void Compaction, glues, ect).