carbon dh frames...what is all the fuss about?

Search for the carbon v10 thread, then grab a comfy chair, crack a beer, and enjoy.

Can I play to?

29er DH frames...what is all the fuss about?

OGRipper said:

Search for the carbon v10 thread, then grab a comfy chair, crack a beer, and enjoy.

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2nd that. Carbon is stronger if done right. Also 500g over weaker alu frames. Much more over burly alu ones

Lighter, stronger, and most likely straighter (unlike a lot of welded aluminum frames).

Also, what is a "marketing trick"? I've never been tricked by a marketer.

Dogboy said:

Also, what is a "marketing trick"? I've never been tricked by a marketer.

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Padded Bras.

Jeremy R said:

Padded Bras.

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haha!! so true

Also, check this out:

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

Race cars do it, so mountain bikes should do it too.













Derp.

Cost of aluminum goes up and up and up. Carbon is everywhere?

My logic is not logic as I am guessing with reckless abandon.

freeriding said:

So why all that fuss and manufuctureres making downhill carbon frames?

How much are the frame weight savings? 500gr?

And what about the risk of crashing hard with the frame, and carbon getting damaged?

Are there any real advantages making them so 'hot', except for the slight weight savings and the 'cool' look?

Is is another marketing trick or what?

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It's called technological development buddy. Do you still run canti brakes and elastomer sprung suspension?

Making a frame that is stronger and 1lb+ lighter is no joke. Just wait a few more years....

Don't fear the future!

The downhill racing scene wants to expand its carbon footprint.

my problem with carbon has nothing to do with a new frame, to me its the lifespan. i think that most bike shops as a rule of thumb recomend replacing carbon road parts every 5 years, and in my experience i would agree with this "rule". so lets say downhill carbon parts are by design much thicker, stronger, shread way more gnar than road parts; i will make up a hypothetical rule of thumb 8 years for a shread gnar carbon frame without scratches. i tend to crash on occasion and dent and scratch my Al frames, so the same would be said for a carbon one, accounting for normal wear and tear lets say the lifespan is 1/2 that. so by the powers vested in me by the Universal Life Church and the sake of argument lets (or not?) agree 4 years of normal wear on a dh frame is a normal. i would like to see a test on frames one Al the other Carbon maybe a cromo as well, all exposed to crashes, uv, and shreading gnar, THEN test the frames. when someone is f.a.f. and gets new frames every year, hells ya stronger, lighter, blacker (neon yellower) whatever, but the privateer/weekend warrior i just dont know about carbon?

btw to me the f1 argument is a farse, most of the carbonz on the cars are one time or one season use.

vinny4130 said:

i would like to see a test on frames one Al the other Carbon maybe a cromo as well, all exposed to crashes, uv, and shreading gnar, THEN test the frames. when someone is f.a.f. and gets new frames every year, hells ya stronger, lighter, blacker (neon yellower) whatever, but the privateer/weekend warrior i just dont know about carbon?

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Did you watch the Santa Cruz video? One of the carbon frames they tested (Nomad I think) had been used for testing initially, ridden for two years, and then tested to failure in the video. It still far outperformed the alu frame.

i saw that. i'm not saying carbon isnt stronger, but that frame is the only one i remember having seen under similar conditions. i still think C is the future the tolerances are better stronger bla bla bla but as of today... its another great material to make frames out of but end all i dont think so. supercarbonspidersilkalinednanotubeskevlarreinforced clear coated with the spunk of a unicorn is the next wave for the bike industry. id call it scssantkr now with U.S. it wont roll of the tounge like d.e.l.t.a. or vpp or app but it'll sell

^^^Yeah, uh, can't argue with that.

vinny4130 said:

i saw that. i'm not saying carbon isnt stronger, but that frame is the only one i remember having seen under similar conditions. i still think C is the future the tolerances are better stronger bla bla bla but as of today... its another great material to make frames out of but end all i dont think so. supercarbonspidersilkalinednanotubeskevlarreinforced clear coated with the spunk of a unicorn is the next wave for the bike industry. id call it scssantkr now with U.S. it wont roll of the tounge like d.e.l.t.a. or vpp or app but it'll sell

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You're an idiot.

vinny4130 said:

i saw that. i'm not saying carbon isnt stronger, but that frame is the only one i remember having seen under similar conditions. i still think C is the future the tolerances are better stronger bla bla bla but as of today... its another great material to make frames out of but end all i dont think so. supercarbonspidersilkalinednanotubeskevlarreinforced clear coated with the spunk of a unicorn is the next wave for the bike industry. id call it scssantkr now with U.S. it wont roll of the tounge like d.e.l.t.a. or vpp or app but it'll sell

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When alum was first used for mtn bikes many people were saying that it was just a fad and that because of a short fatigue life people would be going back to steel.

Modern carbon fiber is lighter, stiffer, stronger, and more impact resistant than alum. Plus, it can be formed to fine tune ride characteristics.

vinny4130 said:

my problem with carbon has nothing to do with a new frame, to me its the lifespan. i think that most bike shops as a rule of thumb recomend replacing carbon road parts every 5 years, and in my experience i would agree with this "rule". so lets say downhill carbon parts are by design much thicker, stronger, shread way more gnar than road parts; i will make up a hypothetical rule of thumb 8 years for a shread gnar carbon frame without scratches. i tend to crash on occasion and dent and scratch my Al frames, so the same would be said for a carbon one, accounting for normal wear and tear lets say the lifespan is 1/2 that. so by the powers vested in me by the Universal Life Church and the sake of argument lets (or not?) agree 4 years of normal wear on a dh frame is a normal. i would like to see a test on frames one Al the other Carbon maybe a cromo as well, all exposed to crashes, uv, and shreading gnar, THEN test the frames. when someone is f.a.f. and gets new frames every year, hells ya stronger, lighter, blacker (neon yellower) whatever, but the privateer/weekend warrior i just dont know about carbon?

btw to me the f1 argument is a farse, most of the carbonz on the cars are one time or one season use.

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I have a friend with a carbon 1998 GT freeride something. I'm pretty sure this carbon is far inferior to todays carbon. This frames has been used for around 15 years. The aluminum is literally crumbling with dozens of cracks. The carbon, looks just fine.

Since random speculation is allowed in this thread i'm going to paraphrase something i read somewhere sometime ago about carbon having good lifespan because of it's ability to absorb the little vibrations and stuff. Yeah...

I'm pretty sure they say the same "lifespan" thing about aluminum too.

Are you really going to use the same bike for 8 years? Ha!

Light aluminum frames like the trek are nearing the limit of the material. A frame the same weight made from carbon is going to outlast its alloy equivalent . There is no heat effected weld zones etc smooth transitions so less stresses.
But something that I haven't seen mentioned yet in the Mtb scene is repairability. I repair carbon frames all the time. It just isn't possible with alloy. Sure you can weld up a crack. But your introducing more heat and embrittlement. And welding up a crack or dent in the middle of a tube doesn't look real pretty. A carbon repair is barely noticeable .
Carbon is simply an advancement in technology that had to happen. I love the stuff. What I dont love is the price rises. Frames are going to rocket in price IMO .

MrPlow said:

But something that I haven't seen mentioned yet in the Mtb scene is repairability.

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I was thinking the same thing. Recently read an article about the growing industry of carbon fiber bike frame repairs (calfee for example). Bottom line is that for $400-500, even a pretty major area of damage can be made like new (structurally and cosmetically) and the bike can be ridden with confidence.

I'm in no rush to convert, but starting to think more seriously about a CF 6 incher frame...

MrPlow said:

Light aluminum frames like the trek are nearing the limit of the material. A frame the same weight made from carbon is going to outlast its alloy equivalent . There is no heat effected weld zones etc smooth transitions so less stresses.
But something that I haven't seen mentioned yet in the Mtb scene is repairability. I repair carbon frames all the time. It just isn't possible with alloy. Sure you can weld up a crack. But your introducing more heat and embrittlement. And welding up a crack or dent in the middle of a tube doesn't look real pretty. A carbon repair is barely noticeable .
Carbon is simply an advancement in technology that had to happen. I love the stuff. What I dont love is the price rises. Frames are going to rocket in price IMO .

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JB weld dat sh*t

I am still baffled by everyone with the "WTF OMG carbonz on biksorz?!" If you don't like it, don't fuss over it! Obviously it has peaked your curiosity too! Or you wouldn't be asking questions.

frorider said:

I was thinking the same thing. Recently read an article about the growing industry of carbon fiber bike frame repairs (calfee for example). Bottom line is that for $400-500, even a pretty major area of damage can be made like new (structurally and cosmetically) and the bike can be ridden with confidence.

I'm in no rush to convert, but starting to think more seriously about a CF 6 incher frame...

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I have repaired alloy frames by wrapping carbon mixed with an specific epoxy. Was very successful
The alloy frame just kept falling to bits in other areas though

for anyone that remembers, i recently started riding carbon wheels on my xc bike. Now i understand why people spend $3k+ on them.

That good hey Jon? Elaborate?
I am still trying to figure out how to make some. Fail.

MrPlow said:

That good hey Jon? Elaborate?
I am still trying to figure out how to make some. Fail.

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stiff as fvck. makes the qr fork i'm running (older model fox vanilla rlc) feel like it has a thru axle. beyond that weight savings is a bonus.

and these are taiwanese house brand wheels.

Some people seem to be a little touchy about carbon. All I'm saying with out name calling is Al and steel bikes seem to be around longer. That reason could be simply there is more of them. Or maybe the development of a carbon bike naturally is more cutting edge? And could get dated quickly and forgotten. Really who is going to get excited about a 90's kestrel, I think many here would not but a Indy fab from the same year would be a "cool" bike.

And yes who rides an 8 year old dh bike? Doesn't the sunday tuning thread still have almost daily posts? When did that frame come out 05-06?

The idea of repaired carbon frame never crossed my mind. I think that is a great point for the many benefits of carbon.

Anybody using Basalt in bikes yet? It's making it's way into skis now and is said to be a cheaper alternative with close to the same performance as CF.

Those tests that Santacruz performed are completely ignoring the fundermental issues with carbon fibre. Of course it will take more ultimate load when the weight is around the same, the material itself is far stronger than Aluminium, congratulations, you've made a spectical for all the fools to go ooooooo look how tuff it is.

I would love to do that same test, but before each one, I'd get an impact rig with a punch on it (simulating a sharp rock) slam it where I wanted to on both the cf and the aluminium frames, then rerun that test and see what happens.

Carbon fibre composite is a fantastic material for a frame, but it still has the problem of almost 0% elongation, so say when a sharp rock impacts your frame heavily, the energy is not absorbed by plastic deformation in the case of an aluminium bike, instead it's done by delamination of the fibre from the matrix. You may think that a very thick layup might reduce the problem and it does to an extend, but the localised force imparted by a sharp rock is incredably high and if it does cause internal delamination, you can't tell unless you do an ultrasound or your good with a tap hammer.

Fibre glass makes a great sacraficial composite layer, but I have no idea what companies utilise such a layer.

Carbon fibre has a lot of benefits, but many drawbacks which really need to be thought about and riders have to understand that the tests that were shown in that PB report play to carbon fibres strengths and none of it's weaknesses.

Also, "2050lbs of force to see it fail" "585lbs of energy " made me cry a little bit you Pinkbike retards.

dilz - just one thing to point out, the tests they showed in the video are highly unlikely to be all the tests they perform on their CF frames.

from what I've seen of treks testing videos, they have addressed each and every one of those issues in both testing and actual application - everything from hitting the carbon with a sharp edge simulating a 1kg rock at 30km/h to the carbon armor in frequently struck parts. How do you feel about that?

William42 said:

from what I've seen of treks testing videos, they have addressed each and every one of those issues in both testing and actual application - everything from hitting the carbon with a sharp edge simulating a 1kg rock at 30km/h to the carbon armor in frequently struck parts. How do you feel about that?

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link or it didnt happen

William42 said:

from what I've seen of treks testing videos, they have addressed each and every one of those issues in both testing and actual application - everything from hitting the carbon with a sharp edge simulating a 1kg rock at 30km/h to the carbon armor in frequently struck parts. How do you feel about that?

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I feel like I'd like to see it. I'm just really curious what they can take, I don't hate carbon, infact I love it, but when somone shows tests that are clearly just designed to make people who don't understand go ooolalaa, it really infuriates me.

Also, can we see these videos? Surely if I was Trek and my testing showed hey yeah our frames can take this impact and still pass the post impact ultimate strength testing I'd be having that video shown to every website around, so more people would buy my overpriced carbon frames.

yesimaddicted said:

link or it didnt happen

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Treks anvil strike test

true story.
I still prefer alu over carbon for dh.

yesimaddicted said:

link or it didnt happen

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dilzy said:

I feel like I'd like to see it. I'm just really curious what they can take, I don't hate carbon, infact I love it, but when somone shows tests that are clearly just designed to make people who don't understand go ooolalaa, it really infuriates me.

Also, can we see these videos? Surely if I was Trek and my testing showed hey yeah our frames can take this impact and still pass the post impact ultimate strength testing I'd be having that video shown to every website around, so more people would buy my overpriced carbon frames.

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p-spec said:

Treks anvil strike test

true story.
I still prefer alu over carbon for dh.

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Google/youtube to the rescue... took me about 2 min to find.

Interesting that they only use that particular layup on a small section of the down tube and the seat stays. My chainstays have rather pointy dents and my top tube receives a hammering in tumbles on rocks.

It's an impressive layup that can take that punishement and still outperform the aluminium bike in post impact ultimate strength tests.

Chainstays on Session 9.9 is still aluminum.
Remedy and Fuel, however, have CF chainstays, but most probably not ridden that hard.