rekmeyata

I got an in depth response from FSA in regards to CF parts; here it the text of that letter, I had to reask the question on the replacement issue because he did skirt around the issue, but now he's more direct:

Hi Rekmeyata;

I did answer the replacement question:

The frame itself doesn’t determine how often a part needs to be replaced. That is dependent on riding style and frequency and cannot be expressed. It is important to regularly inspect all components on your bike.

I cannot give you a set timeline on how often to replace parts as riding style, frequency, and conditions are too varied to say “This post will last X number of years”.

I can tell you that these are lightweight race components. They do have a lifespan, and do need to be maintained/check regularly. We have some people on the same post for 10 years, we have some guys that break them and I have no idea how… it all depends on the rider.

I will say that carbon components should be replaced more often than aluminum, and 3-5 years is reasonable estimate, but I do not have an actual timeline for you.

Patrik

Patrik Zuest
Technical support
Full Speed Ahead/Gravity/Vision

RiPHRaPH

The less you tell them the better. Don't volunteer too much information. See if the Bianchi rep has been in lately or if they can call him/her. You obviously need a replacement frame. Not sure if Bianchi would let you walk to the competition.

idiotekniQues

while he mentioned aluminum is more durable than carbon. he forgot to mention how steel is invincible

prtyich

Ok, have to admit it's been a long day and I'm not on much sleep, but the level of posts on this thread have gotten REALLY useless, such as this one.

Did you or your cohort above read the first 9-10 pages of this thread? If CF was sooooo prone to damage, and with such ease, something tells me that the manufacturers would have long ago stopped making them. The bad publicity would have made the news media, and the bike makers - who are relatively small companies in the grand scheme of things - would have been forced to stop making CF bikes.

I don't care if your mechanic worked there for 1,000 years, he is one person in one LBS in a country of tens of thousands of them, and is not a useful sample of the millions of CF bought and ridden each year without any such issues.

As has been repeated ad nauseum in this thread, no you cannot put a CF frame in a vice clamp because the fibers might not hold, but that has NOTHING to do with its ability to handle road conditions when ridden.

Can we just close this thread already?

prtyich

You attack CF yet are using it on the front part of your frame, in one of the most important impact zones of the bike, yeah that makes sense

prtyich

Bottom line, don't crash a CF bike and it won't crack/shatter on you.

idiotekniQues

Stupid statement, like we can control crashes all the time.

Bottom line, don't crash with a wussy substance and it won't crack/shatter on you.

scott967

I had to stop riding my Paramount when rust on the top tube resulted in a crack. I don't know how compromised the strength was, but didn't want to risk it. So I decided to go crabon for my next bike. It may not last 22 years like my Paramount, but I probably won't be around to find out.

scott s.
.

prtyich

You act as if crashes are a normal part of riding; they are not. I've ridden about 120 -150 miles per week for DECADES in a crowded city, and have NEVER crashed.

Yes, if you buy a composite hockey stick and bang it over the goal it will break, so therefore, a composite stick is a "lesser" product than a wood one. You are welcome to your opinion, but for the vast majority of CF cyclists, their bikes have held up fine. Your posts sound like someone who either couldn't afford or get a CF bike, so now you expend no small effort to attack them unjustifiably. You're not coming out of this looking too honorable.

benaroundawhile

It's the design, not the material.

I've crashed my carbon frame a bunch of times. It's still going strong.

You do get extra nerdlet points for the "wussy substance" bit though. Well done.

idiotekniQues

I don't believe crashes are normal nor abnormal, but they are certainly part of riding a bike for many. Some will encounter them and others will luckily never encounter them. Most are unwilling for the most part. But you act like they are a joke to be laughed off.

Conveniently because you are defending a frame material that has been shown to be more likely to receive damage in that situation vs others. Which you CLEARLY acknowledge by defensively saying 'Don't encounter an unhappy situation with carbon and you'll be just fine'

You actually prosecute your dear frame material with that statement just dammingly. Fool.

benaroundawhile

It's the design, not the material. So many people struggle with this simple concept. It is entertaining though.

rekmeyata

Not the man of steel!

rekmeyata

NOOOOOOOOOOOOOOO, don't close this thread, I'm not having fun with you.

Sy Reene

So, on the design issue. After seeing some bank ad during the NFL game last night, where Jamis bikes was highlighted, I went to Jamis's site. They actually have a pretty neat lineup, including steel, carbon and aluminum models. Somewhat rare to see a maker having all these options.

That said, I was intrigued looking at the below bike. An on and Off-road bike, comes with 36mm Xplor tires, etc.. I know it's unsubstantiated, but I can't help but look at the seat stays on this bike and think that boy they look fragile.. this is the CF version:



OTOH, the same model in 631 steel; and for me at least, I don't know what the weight sacrifice is, but for this type of bike I would not hesitate to select the steel, even if they were the same price. Am I just being superstitious?

prtyich

Seriously so, and you wonder if these people have some kind of agenda given that your one line perfectly sums up an 11 page thread, but they continue to argue as if the earlier posts - some of them highly detailed and academic in nature - never happened.

Some people will stick to whatever nonsense they believe no matter how many facts are thrown their way; it becomes like Linus' blanket / stuffed teddy bear - something they just can't let go.

prtyich

After that strawman, I just can't take anything you say seriously anymore. You are wholly incapable of grasping certain concepts, despite them being repeatedly explained to you.

"It's the design, not the material."

"It's the design, not the material."

"It's the design, not the material."

.....

king_boru

You are judging a book by its cover. You have to look at it from an engineering perspective. The strength has been manufactured into the seat stays accordingly. The same can be said for the new Reynolds 935 steel tubing. It is equally thin in places and would suggest fragility on face value but is quite the opposite in reality.

billdobie

Well...What ever happened???

Sy Reene

No doubt that I could be judging not knowing all of the engineering. I do realize that seatstays have very little stresses applied to them in normal riding, and you can find quite thin seat stays on some bikes from other makes (eg. Giant TCR comes to mind). That said, the TCR is a road bike, not an "adventure" bike. In Giant's line, their TCX bike would be similar function type of bike and they use thicker seat stays.

So call it a rush to judgment and you're probably right, but for a bike where expectation during off-road cycling generally leads to more impacts/accidents (if not more load bearing) -- whether from falls or rocks being kicked up, or whatnot, I can't help but think that these thin CF seatstays could have been beefier without really terribly hurting the bike's weight. Also consider that these bikes are marketed and sold with mounts for racks to be added..

So (on the purpose-built 'design' topic) are these designed for not just for providing a great ride, but built to withstand more abuse?

But perhaps it's not even tubing we're looking at, but maybe these stays are solid throughout and have compensated in this manner. Perhaps what appear to be thicker seat stays on other bikes are tubes and not solid throughout?

travbikeman

Wow, this is an entertaining thread!

Maelochs

This is where prejudice can leave us standing too far from logic to sneak back unnoticed.

Obviously the people who designed this bike knew exactly what it was designed to do and calculated the loads for it. If they could not do that, they could not also design the steel version---it isn't like there is some more abstruse math used with CF. If the steel bike works---since it faces the exact same intended use as the CF bike---the CF bike works.

You see the skinny seat stays and, because you are comparing them to steel or Al seat stays, you think they are too small ... but you are not an engineer. Thing is, you Know that the guys who designed both frames Are engineers. They understand the strengths and weaknesses of various materials in various applications way better than you do---and it is absolutely absurd to think they would deliberately design a bike which was going to fail, when they knew exactly what it was designed to do.

Also, one has to imagine that several frames were built and tested to destruction. Jamis is a Very well respected bike maker---you don't gain that status without producing quality bikes. Plus, they don't have a Trek/Specialized-sized PR department to tell everyone how good they are. They got their name by being good, not by producing good ad copy.

The idea that they would deliberately design a bike which was going to fail is absolutely absurd. And given how many bikes they have designed and built, the idea that they would accidentally design a bike which failed---and then Allow It Into Production---is beyond absurd.

Yeah, to me those seat stays look tiny, much more like road bike seat stays (I do notice the chain stays are larger and more rectangular.) In fact, despite the fact that in the picture the two frames look pretty close, I bet there are a lot of differences between the two, taking advantage of the two different materials’ capabilities.

It goes one of two ways: Either Jamis designed all of its previous bikes buy sheer luck, and has no clue what it is doing, and now finally luck has let them down ...

or ...

Some non-engineer like myself sees a pencil-thin seat stay and cannot understand what the engineer can---that it is perfectly designed for the task it needs to do.

Sy Reene

I thought I specifically said that I was not questioning whether the bike would be likely to fail under load. And I certainly didn't mean to suggest that they built a bike designed to fail. Rather I was questioning to what further extent has this bike been built to withstand abuse over a comparable-level road bike given its marketed purpose is to perform off-road. You mention that bikes are built for their "intended use". To what degree is falling, crashing, rock impacts part of "intended"? I don't know. And yes, I'm judging by appearances which I realize isn't terribly scientific. And, while both the CF and Steel versions of this model may be built to withstand a certain minimum ability to handle stresses and abuse, I don't believe that the CF and Steel version of this bike are built to withstand identical amounts of stresses and abuse.

All bike makers we presume are faced with deciding themselves on the appropriate balance of durability vs weight, and there are tradeoffs. Each maker goes into their design process, deciding for themselves where to fall on the spectrum of weight to durability, no matter which material they choose.

Jamis is a long-standing and respectable brand. I only saw this one model series as a bit quirky. On a related note, Jamis has its roots in steel going back over 3 decades, and this specific series (Renegade) is only a year old.

Just an aside.. it's a pretty nice bike.. no matter which material you look at.

benaroundawhile

Re: Jamis and carbon

"The manufacturing process we pioneered in 2009"

Sy Reene

And now.. in all fairness, I just found a photo of the seatstays from a bike review.. which makes me feel better about the seatstays.. As Jamis only seems to put a side view photo shot on their website, it wasn't evident that the stays are flattened and fairly wide.. Oh well.. was interesting discussion while it lasted though..