Mountain Biking - So apparently carbon fiber is pretty durable

http://www.pinkbike.com/news/santa-cruz-bicycles-test-lab.html

the slam a frame into a concrete block test really sold me.

The fact that it's used in fighter jets, F1 suspension, and ball bats really sold me...twenty plus years ago.

. . . and kick-ass racing canoes.

Screw carbon fiber! STEEL IS REAL! :p

STEEL IS REAL RUSTY! Fixed.




:D

That was pretty awesome. I've never really doubted carbon (which is moot - I've never even ridden a carbon bike). I mean, hell, if it's strong enough to make Formula One frames out of...it should be good for mountain bikes.

Why is there reluctance towards CF in mountain biking anyway?

Why is there reluctance towards CF in mountain biking anyway?
Somebody probably broke a super-lightweight CF frame, and then the material took the blame rather than the construction.

It is all in the build spec.

I work at a bike shop and have seen plenty of broken carbon in real life. Wearthrough is another carbon-killer... pro tip, if your wheel is out of true and it's grazing your carbon frame, DO NOT RIDE IT LIKE THAT. This is why there are cell phones! :D

My own carbon hardtail died of a crack about halfway around the BB shell on the driveside... ahhh, so THAT'S why I was getting so much FD rub, I thought it was my massively powerful thighs or something :thumb: I replaced it with an aluminum one (OH NOES, IT IS 1/2lb HEAVIER NOW!).

i've seen carbon crack, a rock strike at the right angle will do it. even cracked the bike rode without breaking. i've seen my friend ride his mojo hd for quite a while now, he is not gentle with it at all and he is still riding it. carbon is pretty good stuff.

i would say carbon is strong enough to outlast 80% of the people riding bikes. ive talked to people who say they don't think carbon can hold up, i don't tell them carbon bikes are faaaaar more capable than anything they will do with it.

I'm convinced of the durability of carbon fiber, but the devil is in the details, ie. how/how well it is designed and fabricated.

That was pretty awesome. I've never really doubted carbon (which is moot - I've never even ridden a carbon bike). I mean, hell, if it's strong enough to make Formal One frames out of...it should be good for mountain bikes.

Why is there reluctance towards CF in mountain biking anyway?

Lets see pretty well all of Trek, Specialized, Giant, Cannondale Santa Cruz, IBIS, etc etc. highest level XC and all mountain MTB's are carbon.
The last "pure downhill" bikes are going carbon as well. It's more why is there a reluctance to non-carbon bikes.

It's more why is there a reluctance to non-carbon bikes.

Reluctance toward non-CF? Do we need to take a poll of how many people here ride CF bikes vs everything else?

Reluctance toward non-CF? Do we need to take a poll of how many people here ride CF bikes vs everything else?


That's more a price issue than why are all the MFG's totally embracing carbon.

I realize that, but I still haven't seen any evidence at all of anyone being reluctant to buy an aluminum or steel bike just because stronger materials exist.

Nice vid. Thanks for posting.

Lets see pretty well all of Trek, Specialized, Giant, Cannondale Santa Cruz, IBIS, etc etc. highest level XC and all mountain MTB's are carbon.

I work at a dealership for one of the brands you mentioned, and the ratio of broken carbon frames to broken metal frames is very high in real life. Causes vary, but that's the bottom line from years of firsthand work on hundreds of them.

We have one in the shop right now that's cracking in two places where frame tubes took routine impacts from spills. And I'm talking XC-rider spills, not spectacular freeride bailouts. On an aluminum bike, these impacts would just be routine used-bike scratches, not a cause for structural compromise. The warranty department declined coverage because the bike had taken hits in those locations (as evidenced by the scratches in the paint).

If you like carbon and you're not fazed by this sort of thing, then by all means buy it. If you want something that's going to shrug off crash impact, then caveat emptor.

I work at a dealership for one of the brands you mentioned, and the ratio of broken carbon frames to broken metal frames is very high in real life. Causes vary, but that's the bottom line from years of firsthand work on hundreds of them.

We have one in the shop right now that's cracking in two places where frame tubes took routine impacts from spills. And I'm talking XC-rider spills, not spectacular freeride bailouts. On an aluminum bike, these impacts would just be routine used-bike scratches, not a cause for structural compromise. The warranty department declined coverage because the bike had taken hits in those locations (as evidenced by the scratches in the paint).

If you like carbon and you're not fazed by this sort of thing, then by all means buy it. If you want something that's going to shrug off crash impact, then caveat emptor.


Well in the same sort of thread in a different forum I mentioned an aluminium bike getting a 1/2" dent in the frame from "falling over" onto I think it was a coffee table.
And also thin wall aluminium tubing can be less than 4X the thickness of a beer can. So I don't think they can sustain any significant impacts to those areas either.

Well in the same sort of thread in a different forum I mentioned an aluminium bike getting a 1/2" dent in the frame from "falling over" onto I think it was a coffee table.
And also thin wall aluminium tubing can be less than 4X the thickness of a beer can. So I don't think they can sustain any significant impacts to those areas either.

The aluminum doesn't delaminate or fracture, though. It dents if it's hit hard enough, but it's still structural. You don't keep using it for six months and find that the dent has spread all the way around the tube, either.

I think if you asked a Boeing Dreamliner tech, they'd tell you they have a protocol for what to do if their carbon superplane parts take a direct hit from something like a goose. Not "oh haha LOL, the plane is carbon, it is teh invincibles, look at this bike manufacturer's PROMOTIONAL video with the concrete block!" but more like "ok, let's get the X-ray diffraction equipment and go over this before we certify it for flight."

I can remark that the problem is real enough that the brand we sell has added external rubber shields to the undersides of the downtube, as well as beefed up the tube construction, to deal with the threat of rock impact from the front wheel kicking rocks up into the path of the frame. Ask yourself why they'd do that if they didn't have to.

http://www.pinkbike.com/news/santa-cruz-bicycles-test-lab.html

the slam a frame into a concrete block test really sold me.

So what qualifies "passing" the concrete block test? I guarantee they didn't build the frame back up and ride it the next day.

My point being this:...Even though it doesn't "explode" on you during use...you may still have to spend $2k getting it replaced because it's been compromised.

I think replacement interval is the biggest factor going into folk's decision to avoid carbon fiber. Few people dispute that it's a better frame material...just that it's functional durability isn't as solid as a metal frame that can be visually inspected when damage is suspected. So you took a hard fall this weekend...and your frame didn't break...does that mean it's still 100% structurally sound? Most people don't have a mobile x-ray machine at home...and I imagine that most folks also don't like the idea of replacing a $1500-3000 frameset after an unfortunate unplanned tumble in a rock garden.

I'm not against carbon fiber at all, but the replacement cost and interval definitely plays into my decision to buy it. Someday when I have the budget to cover potential damage to a carbon fiber frameset, I may fall in line with everyone else for one. Until then, however....

-Jeremy

Screw carbon fiber! STEEL IS REAL! :p

http://www.esslab.com/iv/elements/element-files/ti.gif

i'm waiting for an adamantium bike

The aluminum doesn't delaminate or fracture, though. It dents if it's hit hard enough, but it's still structural. You don't keep using it for six months and find that the dent has spread all the way around the tube, either.

I think if you asked a Boeing Dreamliner tech, they'd tell you they have a protocol for what to do if their carbon superplane parts take a direct hit from something like a goose. Not "oh haha LOL, the plane is carbon, it is teh invincibles, look at this bike manufacturer's PROMOTIONAL video with the concrete block!" but more like "ok, let's get the X-ray diffraction equipment and go over this before we certify it for flight."

I can remark that the problem is real enough that the brand we sell has added external rubber shields to the undersides of the downtube, as well as beefed up the tube construction, to deal with the threat of rock impact from the front wheel kicking rocks up into the path of the frame. Ask yourself why they'd do that if they didn't have to.

Could this be the reason that the Santa Cruz V-10 has only the front half of its frame molded in CF, while the rear is in Al-alloy?

Regardless of how strong it is or isn't, I find it quite telling the number of people in these forums that have stated that they'd never buy second-hand CF.

But I suspect thats just a complete lack of confidence in their own ability to properly access it.

i'm waiting for an adamantium bikeI keep trying to find an unobtanium one . . . but I can't.

http://www.popsci.com/technology/article/2011-01/new-metallic-glass-toughest-strongest-material-yet

I think replacement interval is the biggest factor going into folk's decision to avoid carbon fiber.

Does that not apply for any frame of any material? I realize that you can fix certain kinds of cracks with certain kinds of metals, but I'd be curious to see a statistic of how many people actually fixed a broken frame rather than replacing it.

Calfee is well known in roadie circles (aka carbon circles) for doing carbon fiber repairs. I don't know offhand of any aluminum shops that will weld cracked frames though.


/still won't be riding CF any time soon, based on dents on my aluminum bike
//would like to though...

saw my buddy today, he had a gray new looking surly karate monkey. i said "i thought your bike was black" he said "it broke, so i got a new one"

A) i didn't know you could break a surly, and...

2) turns out a 4130 cro-mo steel bike on the roof rack will break when you run it into a garage. he didn't fix it, he replaced it.

^Stories like that make me nervous to be rocking a roof rack. I don't park in the garage at home, but parking garages, drive thru's, etc are my worst nightmare.

Does that not apply for any frame of any material? I realize that you can fix certain kinds of cracks with certain kinds of metals, but I'd be curious to see a statistic of how many people actually fixed a broken frame rather than replacing it.

I think you missed my point completely.

I'll go back to the example I made before. If you crash in a rock garden and watch your bike flip upside down and land hard on a rock with it's toptube at a perpendicular angle...what's your move? If your frame is carbon fiber, you know that it's more than adequately strong when used as directed, but is not designed to "be swung into a concrete block" as it were.... But if that does happen, what's your move? If you're riding steel or aluminum, you can visually examine the bike, and likely continue riding it even if the tube is lightly dented. If you're riding carbon fiber, and the paint is scratched with no other discernable damage you have two choices: Do nothing and pray that it hasn't been compromised, or tell the story to your LBS and cringe as they say very clearly "I wouldn't ride it after taking that kind of a hit. We don't mess around with crashed carbon. Do you want us to run a crash replacement on it for you?"

The point isn't whether a bike is dented or superficially damaged, but whether or not you (or even the LBS) have even a chance of making a safe determination about the structural integrity of the frame post-crash. And whether or not the performance increase of carbon over Aluminum is worth riding a potentially compromised bike without any visual cues to work off of. This isn't a big deal if you're using a bike for one or two racing seasons, but if you're planning on riding the same bike for 5-10 years, chances are sometime long before that you'll encounter a situation that calls the frames integrity into question. Personally, I'm just not interested in having to spend the crash replacement $ to ease my mind after such a crash. For some folks, this isn't a problem, especially if they're planning on replacing it soon anyway. Take the loss and don't look back. I just don't make that kind of $.

This video certainly gives me faith in the frames ability to withstand huge amounts of 'standard' abuse before catastrophic failure is reached...but that doesn't mean much to me in terms of dollars and cents to keep my bike in a trustworthy state after non-standard damage.

As I said before, I have no fundamental aversion to carbon fiber. I just tend to think that I can't afford the potential costs or hassle, and don't yet require the slightly higher performance/weight etc. of it over Aluminum. And that may someday change.

-Jeremy

^Stories like that make me nervous to be rocking a roof rack. I don't park in the garage at home, but parking garages, drive thru's, etc are my worst nightmare.That is why I have a pair of Rocky Mounts roof rails collecting dust in the garage . . and why wife's bike now has a suspension fork . . . and new stem and bars . . . and why I now have a hitch rack.

^^ Glad to hear your garage was ok.

Jeremy - Gotcha, I don't know much about CF & didn't realize that it can't be visually inspected for damage.

Doug - That sounds traumatizing. I might start looking into selling my bike attachments to get a hitch or trunk rack. The wind noise & extra fuel consumption are kind of annoying anyway.

Can someone here show me that CF fails catastrophically?

Can someone here show me that CF fails catastrophically?

http://www.bustedcarbon.com/

^^ Glad to hear your garage was ok.It was vs. a concrete parking structure in Bellingham. I designed my garage with a 9' high door because I know me.



Doug - That sounds traumatizing.It was at least irritating and embarrassing. How my bike escaped damage I'm not quite sure. It gave me an excuse to put a susp fork on my wife's bike, anyway ;).

I think if you asked a Boeing Dreamliner tech, they'd tell you they have a protocol for what to do if their carbon superplane parts take a direct hit from something like a goose. Not "oh haha LOL, the plane is carbon, it is teh invincibles, look at this bike manufacturer's PROMOTIONAL video with the concrete block!" but more like "ok, let's get the X-ray diffraction equipment and go over this before we certify it for flight."

It's quite likely they'd do the same for aluminum or steel too!

I think you missed my point completely.
This isn't a big deal if you're using a bike for one or two racing seasons, but if you're planning on riding the same bike for 5-10 years, chances are sometime long before that you'll encounter a situation that calls the frames integrity into question.

Bingo. For example, when my wife's "beer can" aluminum Klein came off the roof rack on the highway at 70 mph, we retrieved it, checked the frame alignment, and then she continued riding the bike with confidence in its structural integrity. When you can do that with carbon, let me know. CF great for race bikes that will be used for a season, but really not very good for somebody who wants to buy a bike they will be able to ride over a long term without worrying about catastrophic failure.

to deal with the threat of rock impact from the front wheel kicking rocks up into the path of the frame. Ask yourself why they'd do that if they didn't have to.
Could this be the reason that the Santa Cruz V-10 has only the front half of its frame molded in CF, while the rear is in Al-alloy?

No.

Only one out of seven Santa Cruz carbon frames are made this way.

I've always been told to put the garage door opener inside my glove. That way, you need to pull it out of the glove before you can get in the garage and, hopefully, should give you that "oh yeah!" moment. It doesn't matter for me since I don't have a garage, but it does sound like it can save you a lot of potential sadness. Of course, that doesn't help for parking garages, drivethroughs, and the like, so my rack generally only gets used if I have a couple of passengers (I can generally fit two bikes in my trunk with the wheels between the trunk and backseat, and the other rider shotgun...in a Corolla no less! But once I get past that, the roof rack comes out).

^^ I have solved my problem by not listening to my wife any more when it comes to driving directions :D.

I was in the process of scoping out a perfectly fine parking space above ground, when she - -quite helpfully - - says "Why don't you just park down there in the parking garage like everyone else?"

I work at a bike shop and have seen plenty of broken carbon in real life. Wearthrough is another carbon-killer... pro tip, if your wheel is out of true and it's grazing your carbon frame, DO NOT RIDE IT LIKE THAT. This is why there are cell phones! :D


Ha! A bike was brought into the shop where I work with the same issue - just a little divot in the chain stay & the frame was toast.

speaking of carbon....has anyone tried carbon wheels? they are pretty sweet, go through rocky tech stuff straight, with no wobble, you point and go. great stuff. the downside is, of course, they are super stooopid expensive....

Don't drink the Kool Aid, homie...carbon is still NOT what it's "cracked-up" to be....impervious to failure. The inherent shock loads, and high probability of accidents in real world mountain biking, make CF a good choice only for those who ride smooth, groomed courses, have much better handling skills and who do not pay for the technology, i.e: sponsored racers.

LOL...Busted Carbon dot com!

Don't drink the Kool Aid, homie...carbon is still NOT what it's "cracked-up" to be....impervious to failure. The inherent shock loads, and high probability of accidents in real world mountain biking, make CF a good choice only for those who ride smooth, groomed courses, have much better handling skills and who do not pay for the technology, i.e: sponsored racers.

we aren't sponsored, we don't ride smooth groomed trails, we probably do have better handling skills, but other than that, i can't say i agree with you. nothing is impervious to failure, but carbon isn't as weak or dangerous as its made out to be.

Have 34,000+ miles on our custom c/f Zona road tandem. No issues.
Have broken a steel tandem frame at 50,000 miles and at 57,000 (right amount of zeroes) miles.
A steel experimental tandem fork broke at 13,000 miles.
Every material can fatigue/fail eventually.
Anyone can build something cheaper . . . and it usually is!
Quality lasts.
Pedal on!
Rudy/zonatandem

...carbon is still NOT what it's "cracked-up" to be....impervious to failure.

Who has ever said that's what CF is "cracked up to be"?? No one here (or anywhere) is saying CF is invincible; just that it's very strong for its weight. I think that the general consensus is actually just the opposite--that CF is too weak for MTBing & should be strictly for roadies. In fact, your entire comment proves that at least one person here think that way, even though there's already a video in this thread proving that a well-made CF frame can handle more stress than its aluminum counterpart.

I'm going to have to say that if it's good enough for the likes of Gwinny, it's probably good enough for me.


http://www.youtube.com/watch?v=ry4WmvmlFwQ

^^^ solid logic

Have 34,000+ miles on our custom c/f Zona road tandem.
You use that mountain biking? That is impressive!

(How is this really relevant to mountain biking?)