alanbikehouston

Many "roadies" think that the "best" road bikes are the bikes with carbon frames, carbon forks, and carbon handlebars. And, carbon bikes probably now have about a quarter or a third of the total market for bikes that cost over $2,000.

Is this obsession with carbon just a "Roadie" thing?

How many BMX riders actually ride a BMX bike with a carbon frame, or a carbon fork, or carbon handlebars. If you have never ridden a carbon BMX bike, how often do you see other folks riding on a carbon bike? How often do you see them in stores? Of the "top of the line - money is no object" BMX bikes on the market, what percentage of models use carbon frames or forks?

My own feeling (correct me if I am wrong) is that carbon-mania is a roadie thing, and the serious BMX riders prefer high quality steel.

FoX Rider

Isn't carbon light but less durable then steel? (Correct me if I'm wrong.)

Maybe the roadies like the parts that weigh less when they don't care about durability. It's not like your doing crazy downhills runs. It's on paved road.

I think its just because they prefer lighter parts over durability. (Not to repeat myself)

Mr.Noobie

i believe we bmxers prefer cromo over steel, lighter material.

edmej123

racers=aluminum

sxe fbm rider

carbon isnt commonly used in bmx.

CMcMahon

Chromoly is steel.

edmej123

lol, i remember when i didnt know that....

BMXTRIX

Yes, chromoly is a steel.

Some (very few) bmx riders ride aluminum frames, but more often flatlanders and racers than any other guys. I suppose it would work for some dirt if the guy is smooth and crazy weight conscious.

Carbon has next to no place in the bmx world. On bikes that take zero pounding (road bikes) or possibly on full suspension mountain bikes, you can get away with some carbon. There is a front hub that uses carbon in it for BMX. But, that's about it. Frames made of carbon get ripped apart in days, not years, like chromoly does. Carbon costs 10 times what the average rider can afford as well.

One of my friends worked at a local bike building warehouse and was amazed at how much road bikes sold for when there was so much less involved with them vs. bmx bikes.

bmxrdr88

yeah and if you get water on the carbon your screwd. my friend has a carbon race frame but he don't ride it. most racers use carbon forks though.

alanbikehouston

From the responses, it seems that no a single person on the forum has actually ridden on a BMX bike with the main frame made from carbon. Is that correct? Not one member has ever ridden a carbon frame BMX bike?

bmxnate

Hey everybody, I am new to the site, but I ride and Avent Morpheus, so this topic looked interesting. If you have any questions about carbon, let me know. If I can't answer your questions, I am sure that my fellow mechanics that I work with can. Oh yeah, I love my frame!!

snakehunter

Road bikes are made from carbon to be light and fast, they dont do the hard pounding gaps and trix that bmxers do. If a bmx bike were made of carbon they would brake easily carbon is good for road bikes and SOME mountain bikes, same reason they dont make down hill bikes out of carbon, just an accident waiting to happen.

BMXTRIX

Yes, when, many years ago, carbon was the shizznit, they made a few frames (I did not follow it closely) and one of my friends who owned a shop had one. I probably rode it for about 30 minutes and enjoyed it. The price on it was hefty.

He snapped it less than a week later. He then went back to his old frame which he had already owned for over a year.

Carbon is simply not able to withstand the forces that are put on it by bmx riders which are incredibly brutal to bikes as far as my experience can tell. Perhaps current advancements may allow it, but very few riders are willing to risk $1,000+ on a frame with ZERO guarantee and a very high chance of failure. If perhaps, someone made the frame, put Dave Mirra on it for a year, and the frame was proven to be strong - that is, they documented him on the same frame for six months, then perhaps carbon would gain one iota of respect in the BMX world, but right now, there is zero respect for it as a suitable material for bikes. Some minor components use a little of it, but that is all.

mtnwing

Sorry to dig up an old thread, but the data shared in here is pretty inaccurate so I'll set the record straight . . .

1) Carbon was first appeared bikes in 1975 with the Exxon Graftek road bike, but this was highly experimental technology and it took about 10 years before folks like Craig Calfee, Brent Trimble, Easton, Yeti, Look, and later Trek started building their first bikes with Carbon tubes. In the late 80's and early 90's when the first carbon off road frames appeared the technology was still very much under development and not well tested so lots of failures occured.

2) By 1995 several top carbon makers had "figured it out" and learned how to make great carbon bikes, but there were also a lot of badly built carbon products still being made. It's just like comparing a department store steel bike with a well built cromoly frame. You can make a great bike or a bad bike out of any material. It's not just the material - it's the design and manufacturing that matters.

3) Since about 2000 there have been several companies making "Downhill" racing frames and components out of carbon fiber. Clearly if these DH bikes which sometimes hit speeds over 50 MPH are subjected to even harsher stress than BMX conditions are successfully using carbon, then there's no reason a good BMX bike couldn't be manufactured in Carbon. It's more a matter of cost. Historically carbon has been more expensive to manufacture because it requires a lot of labor and the material is also more expensive than steel tubes. This is due in part to the ever increasing demand for carbon by the Auto and Aircraft industries which are building more and more in carbon. Carbon is also heavily used in the boating industry. Carbon is "ideal" as a material to be used in water or outdoor conditions unlike steel which suffers from rust problems. Sunlight can affect the longevity of some composites but this problem has largely been solved by new glues and finishing that protects the fibers from UV damage.

4) Carbon manufacturing is getting better and better by the day and costs for parts of the process are beginning to drop as the technology has become more and more popular (although 2005 had a bad "carbon shortage because demand for the material was higher than the factory supplies driving costs up - this is a temporary problem while demand is increased).

6) One of the biggest advantages of carbon construction over steel or welded bikes is the ability to create optimized structures and shapes in designs that put more material where it is needed most and remove it where it is not needed. It's not easy to make a metal shape in anything other than a round tube easily and cheaply. With carbon it is much easier to create unique shapes and create strength by adding thicker layers and fiber alignments in areas that require more strenth while keeping other areas very thin and light. You just can't do this as easily or effectily with metal. In addition without getting too technical, the structural/strength properties of carbon far exceed steel so you can create a stronger bike.

7) The one caveat is carbon failure curve is very different from steel. Steel's properties allow it to bend when it begins to fail, while carbon is much more brittle and when it reaches a ultimate failure threshold it snaps rather than bending. This means that you need to design carbon parts with much higher safety thresholds or "overbuild" carbon products to ensure this doesn't become an issue. Even with overbuilt safety cushions, you can still build most products lighter in carbon than in steel or aluminum. Aluminum also fails similar to carbon in that it snaps rather than bending much, so it shouldn't be assumed that "aluminum is safer".

8) in conclusion, carbon is an ideal material for building performance oriented BMX bikes and parts and will grow in popularity as the price continues to drop. It's no longer a question of the technology being capable to withstand the stresses. This challenge was solved a long time ago and is proven in DH and aircraft industries where failure testing and stress levels are way higher than BMX. The real issue is the economics and also consumer perception. Carbon has gotten a lot of bad press and misinformation has been spread over the years because of early failures. Remember steel bikes been manufactured for over 100 years so there's been tons of time to perfect the design and building process. Carbon really got it's start around 1987 when multiple builders really started pushing the material so it's advanced pretty fast but, it did take some growing pains to get there.

For more on the history of carbon in cycling visit:
www.carbonbicycles.com

-mtnwing

Dannihilator

For BMX racing yes, for all other aspects, carbon fiber won't cut it.

hypersnazz

Thanks, mtnwing, for actually knowing what you're talking about and saving me the trouble of writing the exact same things. No one else, not even BMXTRIX (and I respect his opinion, but it's not very up to date on composite technology, and why would it be?) had anything current or remotely accurate to say on the matter.

The #1 reason (I believe) carbon is not popular in BMX is price. BMXers don't have deep pockets, roadies *do*. The other major factor involved is a general lack of interest in R&D from companies with the means to develop and produce strong, lightweight, reliable and perfectly safe carbon components. Big companies know BMX isn't a moneymaker and don't throw a lot of money *into* it. And the top-shelf BMX equipment is primarily produced by small, grassroots comanies with little to no actual R&D capability beyond a few pro riders who say, "This broke, let's make it beefier," or "This is too beefy, let's make it lighter." That is NOT engineering.

hypersnazz

Dude. CF is used reliably in much more high stress (and high-impact) applications than BMXers will EVER dish out. I know BMXers like to jerk off to the idea that they abuse their equipment more than anyone, but they don't.

zx108

carbon fibre is stronger that other stuff. but it had a tendency to snap, crack, and fail. i have seen pics of carbon seatposts broken, a ton of bars snapped. it doesnt hold up to abuse that mountain bikers give it , then it wont hold up in bmx.

hypersnazz

So? Steel bends and it's just as useless. And I think you're forgetting that mountain bikers, particularly freeriders and downhillers, are MUCH harder on their sh*t than BMXers, and there's a fair amount of plastic on those bikes nowadays. The only difference is that steel and aluminum are cheap to replace.

zx108

i wasnt talking about dh and freeriding, i was talking about cross country. they do make carbon bars for dh, but most racers will still use an aluminum bar. it is harder to bend steel than to put a crack in carbon fiber. you can bend steel a little and it will be fine, if carbon fiber starts to go bad and that is it you cant use it.

hypersnazz

Bars are not a good application for CF...even many roadies shy away from them (especially racers). The trouble with bars isn't necessarily the shatter factor (which is sort of myth, sort of not), it's the incredibly chaotic manner in which bars are stressed and flexed. Forks and frames, for example, take abuse in a more predictable manner, making the job of engineering carbon layup easier and making the material less suceptible to failure if it *does* take a few hits or scratches.

Brian

The only CF I've ever seen in BMX racing is forks, and they seemed to be carbon-wrapped.

Oh, and headset spacers.

-=(8)=-

FMF has a frame thats about 3/4 carbon.
I know more about motorcycles than bicycles.....and Ive heard too
many pros say they will NEVER race carbon wheels.
You will never see anything carbon on an enduro bike......
Gimme steel over anything else !

Dannihilator

Steel can be restraightened carbon fiber can't.

Brian

Carbon fibre can't absorb shock. I think maybe it doesn't resonate or something like that. I should have gotten an engineering degree instead of art - it would be so much easier to explain these things.