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Discussion Starter · #1 ·
OK, I currently own an 04 Stumpjumper Pro. I love it! I climbs really well. My only complaint is the low bottom bracket. But because it has a low bottom bracket it corners really really well. I plan on purchasing a new bike in the near future and was planning on buying a new Stumpjumper but in Carbon. The new Stumps are a bit more relaxed and have more travel than my current model. I believe the BB is higher too!

My LBS happens to carry Pivots, and they like them however most of them are partial to Specialized's FSR suspension. I say to each their own. That being said, for the past year, I always thought my next bike would be a Carbon Frame, because I have been told/taught that carbon is superior to any metal. I really like what I read about Pivot. Why no Carbon in the frame? Are these bikes more beefy/durable than Carbon affords?

FYI, I was looking at the Mach 5. This isn't a gravity Dropper is it? so why no Carbon?

Thanks!

Wayne
 

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The rocker link on Pivots are carbon.

Anyway, conjecture sucks, so here's a quote from an interview with Chris Cocalis (founder of Pivot):
Any reason you didn't go for carbon instead?

I have a fair amount of experience working in carbon and think that it's a fantastic material. There is a lot of development going on in the world of composites and its application in the suspension world. Most of the companies offering carbon models are not seeing a big weight decrease, if any, from their carbon fiber frames. They claim the big benefit as being greater stiffness, but that comes from the size of the tubes and not the material.

Others that do get the weight down suffer in durability and/or frame stiffness. I have ideas on how we can achieve both, but carbon fiber development takes a longer time and should not be rushed. We'll have an incredible carbon model when the time is right but don't hold your breath for 2009!
Source
 

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Discussion Starter · #3 ·
Huh. I guess with all the hype of carbon bars, and carbon frames, I figured my next mountain bike should also be make of carbon. I know when I was demo-ing road bikes a few years ago, I could tell a huge dfference in ride quality between the aluminum frame and the carbon frame. I did end up buying the Carbon Roubaix.

SC claims the new carbon Blur is "Nomad Strong". And I hear they have a Carbon Nomad in the works for 2010.

I am not opposed to aluminum, but I keep my bikes for a relatively long time, so I would like to get the latest technology available at the time of purchase. I have also spoken to many LBS's and they too claim that carbon is superior to aluminum in every way. They all claim it is stronger than aluminum, lighter, and will last longer. I always question them why we don't see more Big Travel Bikes (like the Specialized Big Hit) constructed from Carbon. They respond that the those type of bikes do better with aluminum, and the the technology isn't there yet to provide the kind of impact resistance that those bikes need in a carbon fiber build.
 

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Wayne said:
Huh. I guess with all the hype of carbon bars, and carbon frames, I figured my next mountain bike should also be make of carbon. I know when I was demo-ing road bikes a few years ago, I could tell a huge dfference in ride quality between the aluminum frame and the carbon frame. I did end up buying the Carbon Roubaix.

SC claims the new carbon Blur is "Nomad Strong". And I hear they have a Carbon Nomad in the works for 2010.

I am not opposed to aluminum, but I keep my bikes for a relatively long time, so I would like to get the latest technology available at the time of purchase. I have also spoken to many LBS's and they too claim that carbon is superior to aluminum in every way. They all claim it is stronger than aluminum, lighter, and will last longer. I always question them why we don't see more Big Travel Bikes (like the Specialized Big Hit) constructed from Carbon. They respond that the those type of bikes do better with aluminum, and the the technology isn't there yet to provide the kind of impact resistance that those bikes need in a carbon fiber build.
I am a Research and Development Engineer in the aerospace composites field, been doing this going on 9 years, while composites are very good materials in terms of strength, stiffness and fatigue, they are not great materials in terms of impact and more importantly strength after impact, especially the composite materials currently most widely used in the bicycle industry. If the impact is great enough to fracture the resin holding the strong, stiff fibers in place, failure is imminent, and often times catastrophic. Often times the part will appear un-damaged to the naked eye after the impact as well, as most of the damage is in the layers below the surface and out of sight and can only be seen with ultrasonic inspections and a few other techniques.

So my typical answer to people asking this question depends on how they ride and where they ride. If you are a typical XC rider and prefer smoother trails and rarely crash, a carbon bike may work very well for you. If you ride rocky trails where a lot of chunk gets thrown up from your front wheel at your downtube and where if you crash your bike is likely to get bounced through a rock garden I would steer clear of a carbon parts. My bike is all aluminum, even though I work with composites 5+ days a week. I ride rocky trails and like to hit jumps and drops, and recently have been crashing a bit as my skills and balls continue to grow....

In short composites are not ideal for everyone and everything...:nono:

B
 

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Discussion Starter · #5 ·
Thanks Mr. Yelltzen. I appreciate your input.

I still need to wait for Chris King to come out with a conversion for my ISO hub to the 15mm QR prior to purchasing. They tell me it should be out sometime this summer.
 

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Another couple of things to consider, regarding carbon being "superior," is that carbon's strength and reliability is determined in a very large way by the skill with which it is laid. Aluminum is a lot more predictable in that factor--welds are a lot easier to inspect, and you can pretty much rely on every chunk of metal to behave the same. Then there's the cost issue... carbon isn't cheap, and as far as I can tell, the better the technology gets, the more applications and demand there will be for it, so the price is likely to continually go up.

Last thing to think about, carbon fibers are just that--fibers--and anything made out of the stuff is basically a basketweaving project frozen in resin. :)

I'm not a carbon hater, I think it's fantastic stuff and can eventually fulfill the promise of better than metal (except for price), but right now it's similar to any other material that has its pluses and minuses.
 

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Discussion Starter · #7 ·
It just seems like the Carbon Fiber has really entered in the mountain biking world as of late. Forks, cranks, wheels, bars, and now mtn bike frames.

I have looked at the SC Blur, and it is very pretty, and quite lightweight too. I like what the LBS tells me about that bike. However I don't think I want to buy an SC, as too many of my riding buddies have had their frames crack. And these frames are 100% aluminum with no carbon. I for one would rather not have to deal with a cracked frame. Sometimes SC will work with them, other times they won't. ( I am not too impressed by SC's frame warranty replacement policy) Keep in mind me and my buddies are "weekend warriors. We see maybe 500 miles a year on these bikes.

I guess that is one of the many reasons why I like my Stumpjumper......the warranty on the frame. I wouldn't say I am overly aggressive or even abusive on my bike frame, but I don't have the soft riding skills either. Still it is nice to know that in the unfortunate event that the frame is gets cracked, that Specialized stands behind it.

I have always been a little skeptical about the whole Carbon thing. I have seen/heard too many broken carbon handlebars, seat posts and road bikes frames. But like I said, I tend to keep my stuff for a long time, and try to buy the latest technology so it isn't outdated overnight. It seems like just about everyone is building bikes out of Carbon, and it could be the next new Aluminum. I recall when the "high end" bikes were aluminum and the cheaper ones were alloy. It seems like now days even the low end bikes, with the exception of Dept. store bikes are all aluminum. Will Carbon be the same way in 2 years? I don't know.

Off the topic, one thing I don't like about Specialized as of late is all the integration. Forks, Shocks, components. The specs, all say custom "X" for specialized. I just don't like that at all. I kind of like to know exactly what crankset I am getting. Instead I am being told, "it is kind in between LX and XT". Who wants that??? I have been very pleased with the FSR platform, but I don't think I will buy another bike from them as long as they are doing this with their builds.
 

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Wayne said:
It seems like now days even the low end bikes, with the exception of Dept. store bikes are all aluminum. Will Carbon be the same way in 2 years? I don't know.
I wouldn't worry too much about that. Maybe in 20 years? Who knows. Riding on a dept store carbon mountain bike would scare the crap out of me though...
 

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Wayne - I am in the exact same situation as you, I have been riding a Specialized Stumpjumper FSR for years, love the bike in general, hate the BB height and associated pedal strikes. I can't afford to replace my bike every few years so I look for really durable equipment. I have ridden everything under the sun looking for my next bike I was going to go with new stumpjumper fsr but I took a demo bike out for a day and still had the same pedal strike issues, the horst link just has too much squat for me. I have also demo'ed the Blur LT2, Ibis Mojo, Giant Reign and the Mach 5. All of the bikes are nice, (the mojo seemed flexy to me and had more pedal strikes than my FSR), but the Mach 5 just fit me. I loved everything about it, it is not the lightest bike out there but it is light enough and just feels bullet proof. I am now just waiting for the 2010 fox products to be added and I will place my order. My advice is ride as many different types of bikes that you can, don't limit yourself to Specialized just because it is what you always have ridden, I love specialized but there are a ton of other quality options available.
 

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Discussion Starter · #12 ·
Dave, I do need to demo more bikes. I have ridden the Blur LT, and really like it. BUT like I said I have had 4 buddies who ride the same style I ride who have cracked their SC frames. 2 have Nomads, and 2 have Blurs. The Customer service just isn't there with SC. That is too bad, because I really liked the way the LT handled and felt.

Bedell, I am not too familiar with the Mojo, so I will have to take a look at those. They sure do look good, and they have a dealer not too far from my house, so that is good! I will have to see if they have one to Demo. It is also a Specialized Dealer, so it will be interesting to see how they like it vs. the Stumpy.

Kind of OT here: why do many bike companies only offer a 2-3 warranty on the frame? I haven't had to used this warranty on any bike I have owned, but it feels good to know that I am covered in the unfortunate event of a failed frame.
 

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Wayne - Carbon bicycle frames are not "the latest technology". They have been around since the mid 1980's. Aluminium frames will be around for a long time to come. Aluminium is also advancing in its technology - hydroforming, more efficient production/manufacturing costs, adaptibility - it is a very versatile and durable material and should not be overlooked.

Pay more attention to the latest suspension technology and designs. You will find greater long-term benefit and value in purchasing an advanced suspension design as opposed to what material the frame is made from.
 

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Wayne, Bortis is on the right path, asking what type of riding you'll be doing ect. Carbon is great for road bikes and XC bikes, but for agressive trail riding, The technology just isn't there yet. Carbon is the wrong material to use when forces from multiple angles are being put on the carbon. Here is an example of Carbon being used in the wrong place for the wrong type of riding........
 

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El Chingon said:
Wayne, Bortis is on the right path, asking what type of riding you'll be doing ect. Carbon is great for road bikes and XC bikes, but for agressive trail riding, The technology just isn't there yet. Carbon is the wrong material to use when forces from multiple angles are being put on the carbon. Here is an example of Carbon being used in the wrong place for the wrong type of riding........
HOLY CRAP!
 

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sam575 said:
Wayne - Carbon bicycle frames are not "the latest technology". They have been around since the mid 1980's. Aluminium frames will be around for a long time to come. Aluminium is also advancing in its technology - hydroforming, more efficient production/manufacturing costs, adaptibility - it is a very versatile and durable material and should not be overlooked.

Pay more attention to the latest suspension technology and designs. You will find greater long-term benefit and value in purchasing an advanced suspension design as opposed to what material the frame is made from.
Aluminum also gains fatigue life if alloyed with Scandium. Salsa actually integrates Sc-Al flex members in some of their suspension designs (eg. El Kaboing & Big Mama). I'd like to see a comparison of Salsa's full-sus models to DW-Link bikes.
 

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Discussion Starter · #17 ·
It will be interesting to see what changes/improvements Pivot comes out with in 2010. I don't believe I will get anything before the spring anyway, as it just isn't in the budget.
 
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