The Carbon Impact

I've been going through my archives and I stumbled upon this "article". The Carbon Impact started life as a blog post for the BTCEB website as "BTCEB No 17 The Carbon Impact".

Carbon fiber frames, components and even wheels are hot, hot, hot. But just like Newton's laws of motion, there's no such thing as a free lunch.

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Hey cats and kittens. If there’s been one constant in the development of bicycles it’s the near unending quest for lighter, and stronger materials. An amazingly wide range of materials have been used throughout the years, bamboo, hickory, iron, cromoly steel, aluminum, magnesium, beryllium, titanium, fiberglass, and now, carbon fiber.

            It’s easy to say that carbon fiber is the shape of the modern bike. Look at the pro peloton as they race through the countryside of Europe and almost every major race team is using a carbon fiber frame if only for time trials.  The bikes are sleek, sexy and pretty darn amazing if you ask me.

            Mountain bikes too are not immune to this wonder material. Frames, forks, seatposts, cranks, swing arms, handlebars, barends, pedals, heck, almost everything but the chain.

            But, as with so much with life, it comes with a cost. Almost since it’s introduction to the market there have been naysayers.  Early on there had been problems with galvanic corrosion, questionable laminate layup practices, experimental epoxy formulas, quality control issues, poor notch sensitivity and the remaining unknown question concerning fatigue life.

            A lot of these problems have been sorted out, largely by using the riding public as guinea pigs, and improved manufacturing practices. It’s not that bicycle companies are knowingly sending members of the riding public out on unsafe bikes and just crossing their fingers and hope that the number of frame failures are not high and the numbers of injured cyclists are low.

            A sizeable amount of research and development goes into these bikes, especially the high end ones but it’s simply a matter of degree of sophistication that goes into the development of these machines. Powerful computers that help in design and to help simulate real world applications represent the high end but, obviously, that can only extend so far because, ultimately, some one has to ride them and give their feedback to the boffins.

Granted, there had been a couple of carbon frames that had hit the market without a lot of computer aided design work but with mixed results. Given the choice between racing down Mt Diablo on an old lugged carbon Vitus or a new BMC SLR01 I know which one I would take, thank you very much.

There’s been a lot of talk concerning carbon fiber concerning its relative merits in the bicycle world, especially with mountain bikes. Even amongst engineers and designers it’s still a matter of debate. I have one friend who loves it and makes their living designing frames for a high profile company but on the other hand I have another friend who does stress analysis for rocket booster engines who wrote their masters thesis on carbon fiber who refuses to let her boyfriend ride with any carbon fiber on his bikes.

Personally, I lack the ability to sift through reams of statistical analysis gleamed through years worth of painstaking research and hope to understand it. Truly, there was a reason why I stuck it out in the art department.  But it seems to me two things missing in a lot of the discussion concerning carbon fiber, 1) ride quality, and 2) environmental impact.

In actuality the first point, ride quality, has all but disappeared in the larger discussion concerning contemporary bicycle designs. Twenty years ago you couldn’t leaf through a cycling publication without stumbling on at least one passing reference to the subject per article but now you would be lucky to find a one.  The preference for ride quality has to somewhat like the elusive Goldilocks Mean, not too hard, not too soft but just right.

I’ve ridden some bikes that were so stiff that you swore that you had chipped a tooth along the way. Any one remember the Klein Adroit? Twenty-two pounds of oversized aluminum love with a one piece Mission Control 2 stem and handle bar combination with an extra oversized aluminum unicrown fork?  Extra koosh. 

Then there was a bike that was the opposite end of the spectrum, a pre monostay version of a Bontrager cyclocross bike. Back when Keith was actually making bikes a messenger buddy of mine inherited an early example of Bontrager’s handiwork, a one season, team issued cyclocross bike. It was ultra light, especially concerning it’s age and was painted a dusty blue but it was so flexible that you could lean your knee into the top tube and bend it so much that you could actually feel the top tube give as you sank you knee into it, yikes.

While both of these bikes exhibited some desirable characteristics, light, and for a rigid climbing platform, the Klein, but the Bonterager’s lateral-flex made quite a handful and the Adroit’s rigidity was jarring to say the least.

With carbon’s reputation for easy of manipulation (ranging from tube wall thicknesses to tube shapes) but the promise of eeking out bikes that were light, strong, and relatively inexpensive, with highly desirable ride characteristics remains tantalizingly just over the horizon.

While I’ve ridden a number of carbon bikes over the years, some horrible, some acceptable but I have yet to find one that I fell in love with. 

One of the unavoidable consequences of carbon fiber manufacturing and production is the large amounts of toxic waiste it produces. It’s not to say that other frame materials are particularly eco friendly either. Even just cutting carbon fiber tubes has a long list of problems. According to the MSDS (Material Safety Data Sheet) from SPI Supplies (a manufacture of carbon fiber) counts as part of it’s CIRCLA hazard ratings a low toxicity rating but the inhalation of graphite causes, “benign pneumoconiosis (graphitosis). Symptoms of pneumoconiosis from graphite exposure are dypsnea, coughing, black sputum, bronchitis, ventricular hypertopy and impairment of pulmonary function”.  Um, wear a respirator while cutting it, okay?

            It is interesting to note, however, that the EPA (Environmental Protection Agency) as of yet have any studies pertaining to either the exotoxcity of carbon fiber or any recommendations of the disposal of carbon fiber byproducts other than it should comply with local, state, and federal regulations regarding health, air and water pollution.

           

One of the key ingredients to epoxy resin (essentially a glue that helps carbon fiber bond) is a little something called epichlorohydrin and according to the EPA, “Epichlorohydrin is mainly used in the production of epoxy resins.  Acute (short-term) inhalation exposure to epichlorohydrin in the workplace has caused irritation to the eyes, respiratory tract, and skin of workers.  At high levels of exposure, nausea, vomiting, cough, labored breathing, inflammation of the lung, pulmonary edema, and renal lesions may be observed in humans.  Chronic (long-term) occupational exposure of humans to epichlorohydrin in air is associated with high levels of respiratory tract illness and hematological effects.  Damage to the nasal passages, respiratory tract and kidneys have been observed in rodents exposed to epichlorohydrin by inhalation for acute or chronic duration.  An increased incidence of tumors of the nasal cavity has been observed in rats exposed by inhalation.  EPA has classified epichlorohydrin as a Group B2, probable human carcinogen”.  Lovely.

Another MSDS report not only links epoxy resin to similar repertory ailments but if dumped down the sink it has been linked to fish kills. “If released into water it will be lost primarily by evaporation (half-life 29 hr in a typical river) and hydrolysis (half-life 8.2 days). It will neither adsorb appreciably to sediment nor bioconcentrate in fish. If spilled on land, it will evaporate and leach into the groundwater where it will hydrolyze. Biodegradation and chemical reactions with ions and reactive species may accelerate its loss in soil and water but data from field studies are lacking. In the atmosphere, epichlorohydrin will degrade by reaction with photochemically produced hydroxyl radicals (est half-life 4 days). There is a lack of monitoring data for epichlorohydrin in all but occupational settings. Humans will primarily be exposed to chlorohydrin in occupational settings”.

 There you have it. A bike held together by poison. Enjoy.

           

Adam H