rockabilly808

so I come from a background racing sailboats and when carbon fiber bagen to find it's way into racing sailboats a number of years ago it seemed like magic due to it's weight but carbon structures began break, and so began to the debate as to whether or not carbon is a suitable buolding material, since carbon is extremely strong, extremely light but also amazingly brittle, so it came down to the fact that carbon structures need to be over built. but the suspicion remains. when carbon found it's way into cycling were there any issues like this with components breaking and certain people not trusting carbon?

Crash716

the debate will continue for ever...but i think the results speak for themselves..


almost every rider in the Tour de france is riding a carbon bike...

they don't suck...but there are still allot of crazy people that believe they just self destruct.

jleslie

When carbon fiber composite structures are properly engineered by people who truly understand the materials as well as the required structural loading conditions, and then built by people who also truly understand the materials, the results are usually great.

People used to metal tubing design according to metal alloy properties, which are isotropic, and dimensions like wall thickness and tubing diameter. With composites, you have to look deeper. The mechanical properties of a piece of tubing also depend on which carbon fiber (there are many different types and grades) is used and in what directions the fibers are oriented within the tubing wall. Metals have equal properties in all directions and composites only have properties in the direction of the fibers, similar to the grain in wood. Like plywood, composite tubing properties are built by combining layers of fibers oriented in the directions required to achieve the desired properties. I still get calls all the time from people who want some carbon fiber tubing with the wall "about 1/4 thick", that don't have a clue how it will be loaded in whatever they are trying to build. The tubing itself MUST be designed for it's intended use.

I wouldn't worry too much about what is marketed today by any big name in the bicycling industry. By now they have done their homework. Even though I am President of Advanced Composite Products and Technology, Inc. (ACPT), I ride steel because I like the ride and because I figured I could stand to lose weight off of myself before the added price to get a lighter bike would make any difference to me. Also, any way you look at it, carbon fiber composites do not take impact as well as steel and there is no cheap way to repair a composite frame if damaged.

Jim

rockabilly808

i'm really not corcerned but i was just curious about whether or not carbon had similiar issues in cycling, the problem they've run into with boats is wanting them lighter and lighter sot ey underbuild structures that need to bebulked up, they could get away with this to a degree with fiberglass since fiber glass will flex a bit, carbon on the other hand will just crack and in some cases fail catastrophically so it sounds like cycling ran into similiar issues with carbon structures failing big time.

dpr

Rockabilly please can you write in paragraphs and sentences. It's not hard to understand you, but its kinda like finger nails on a chalk board; it just must stop.

Edit: Corrected Its. If I am going to be a grammar nazi, I also shall ensure I am not a hypocrite!

Boudicca

Capital letters are rather nice too. They help poor readers understand where something starts.

rockabilly808

Sorry folks, will do.

Bekologist

I have read the CPSC will be reviewing and perhaps radically overhauling bicycle manufacturing safety standards in 2008, partly due to the proliferation of carbon fiber into the bicycling industry.

If you want that lightweight carbon crankset, better buy it now, they may soon have to be overbuilt to meet new CPSC safety standards.

I'm one of the naysayers of the carbon camp. Carbon framesets, one deep scrape away from a new bike.

operator

Carbon fibre is great. Just know the failure mode - there is no warning like there is for steel and you really won't be bending anything back in an accident to get you home. No matter how minor.

Other than that, CF 4tw.

atomship47

fill in the blank with any frame material.

CRUM

This is al least the second time CF has made an attempt to break into the cycling market. At least this time, there has been some real progress and some products work as advertised. Back in the 80s and into the early 90s, CF was more of a crap shoot than it is now.

Indolent58

"Attempt"? "Second time"?

Have you been going to bike shops regularly in the last 20 years? CF never went away and has been steadily gaining market share as the cost of CF becomes more affordable relative to other materials. I have been riding one of those crap shoot bikes (a Trek 2100 series carbon/alu frame) for 14 troublefree years and just recently replaced it with a Look CF. CF dominates the middle and high end of the road bike market and even low end bikes have increasing CF content each year.

BTW have you checked out those heavier-than-air-flying machines? I hear some of them work pretty well too.

iamlucky13

Absolutely yes! In addition, part of properly engineering a composite structure is choosing a matrix material (epoxy, plastic, etc.) suited to the task, with its own properties accounted for in the design analysis. The fiber isn't the whole picture in carbon fiber composites.

CRUM

I would say owning a bike shop for the last 18 years might qualify as "going to bike shops regularly".

No, CF never went away. I never said that. But this is the 2nd big surge in those years you speak of. You might enjoy quibbling, but my point still stands.

Brian_1

+1 Smart post.

I ride a steel bike pretty much for the same reasons, but I don't care to hear some riders say, "So, you ride a plastic bike?" anymore than I like hearing, "Steel is real" - either statement rubs me the wrong way. My layperson understanding is that carbon composites/carbon fiber, is essentially an epoxy (plastic) compound reinforced with graphite textiles specifically designed in thicknesses and shapes for the intended purpose. If carbon composites are increasingly used in race cars, aviation applications, and on spacecraft - I suppose they can work fine in bicycle frame construction. One day I may own a carbon composite frame. I already have a carbon fiber Reynolds fork (which I like better than the steel fork I had before) on my steel frame. Right now my bike is fine the way it is. I applaud all who embrace the latest bicycle frame technology, but I also appreciate the older methods of frame construction.

Rev.Chuck

Maybe he was trying to be funny?

aaronspoker

I might have an incomplete understanding, but as I understand it, all load-bearing carbon components will eventually fail, and that on most bikes, this fail point comes fairly soon. This is also true of steel, which will fail after so many stress cycles, but the number required is usually so far out its not worth considering. Also, carbon can fail catastrophically for significant overloads, whereas steel is less inclined to do this--and can often be repaired.

A lot of people seem to point at racing bikes as vindication of whatever fragile material, but I don't think that means anything outside of racing. Racing bikes only have to withstand a single race, in no more than 18 hour runs. So what Lloyd Flandis used on the Tour might be great--if your bike doesn't need to last any longer than a day.

Carbon spokes are a pretty good example; they're super light, but they can fail almost immediately. Aluminum cassettes are probably another: they have a tendancy to "melt like butter" after a few days, despite giving quite significant weight savings.

Bekologist

we've already seen a set of Mavic R-SYS wheels with failed spokes at the shop.....

CRUM

Aren't we all?

biffstephens

I love my CF bike.....in fact I have only owned a CF bike....

I would consider it "viable" at this point.....perfect? I a sure not.....but viable yes....

rockabilly808

well CF technology is improving across the board both through R&D and also by trial an error, but personally I think it's unavoidable that carbon structures will continue to fail now than then but less and less as knowlege and technology about carbon improves.

stapfam

As an Ex-Fibre glass laminator- I do use CF forks and seat stem- But I also understand that it could fail at any time after a knock- even if you check the thing out visually for damage. Well made and Designed CF parts are good- but it is the failure rate after relatively minor knocks that I will not trust.

And I can remember the early 90's when CF Frames were the new wonder material- and I can also remember how much they were distrusted aswell so Crum is right- We are on CF for at least the 2nd time around.

rockabilly808

Sounds like a classic case of weighing the benefits and advantages against the risks and disadvantages. Carbon is extremely light, very strong and very stiff, the major downside and where the problems all stem from is the fact that carbon fiber is brittle.

Cyclist0383

One of the big factors in whether to buy CF or not is how much you ride and how long you plan on keeping your frame for.

Personally I view CF frames as excellent for serious racing, but something that is in essence disposable.

People who buy CF often want the latest and greatest, so they often will update their frames within a year or two. Thus longevity and durability of CF isn't really an issue.

How many folks here ride five year old or older CF frames and how many ride five year old or older metal frames?

Nikephoros

I think people are too busy arguing materials when they should be arguing workmanship.