GeneO 

It must be winter in some half of the world.

SethAZ 

Warning: this is an aside, unrelated to bikes, carbon fiber, or traditional manufacturing in any sense. If you're interested, here's a wikipedia article on "lucky imaging," which is actually quite an interesting idea. They literally do "inspect quality in" to an image by taking tons of low quality images (this is astrophotography so they're taking pictures of stars, galaxies, etc.), inspecting them via computer algorithm, and then combine only the best quality images from the whole sample population, ending up with a higher quality image than would be possible from any given image of the sample set, and also better than could be had by just taking a single exposure over the same length of time as the samples were taken.

I agree that a manufacturer can't "inspect quality in" to the products they manufacture, but they can certainly "inspect quality in" to the stream of finished products actually released into the supply stream, simply by weeding out all the ones that don't meet the particular quality standard.

I think that a lot of what was missing earlier in this thread was also a recognition that product design necessarily incorporates some sort of understanding of the manufacturing processes that will be used to produce that product. If a particular feature is known to be difficult (or impossible) to manufacture in its ideal form, a designer can attempt to design a solution that is not the ideal solution, but which results in the feature at acceptable cost and quality, etc. Thus we don't know that the ugly seat stay/seat tube joint featured at one point in the video is in fact evidence of failed design and manufacturing, or simply design that factored in the recognition that that joint would be difficult to achieve in perfect form, so included an imperfect (and ugly on film) solution which nevertheless achieved the objectives.

memebag

Agreed. Are you open to improving yours or does the current level meet your requirements?

Dean V

I don't think comprehension is the problem.
It just seems that peoples views are extremely varied on what to me seems straight forward.
That BMC was poorly made!
It is that simple.
It doesn't matter if it performed its job, didn't kill/maim anyone etc.
In my mind, at that price point, construction of that "quality" is unacceptable.

Seattle Forrest

For what it's worth, I broke half a pair of Swix Star ski poles last year. Landed on it in a crash, and it snapped in two. It's 100 % carbon. Curious after reading this thread, I just peered into both halfs, the interior looks smooth and flawless.

(I still have them because the warranty covers acts of stupidity, I'm going back to the town I bought them in this weekend.)

chaadster

Yeah, well, if someone cannot even correctly summarize an alternate viewpoint, that's a fundamental failure of comprehension. If one cannot understand and process what they are reading, one does not have comprehension.

pvillemasher

All I gotta say...

Bike Gremlin

Yes, apart from (IMO) a greater risk of a stem failing, you often get it stuck.

With threadless stems, probability of two bolts breaking at the same time is very small. That is because they usually break from fatigue (just like quill a stem bolt) - unless they break when screwing them in by too much torque. Quill stem bolts do break. I've had it happen (at a low speed fortunately). And I'm not the only one.

Kontact 

I think you stand a greater risk of a lightweight hollow stem or carbon steerer tube breaking. There are many spots for single point failures on all bikes.

Bike Gremlin

That is true. You also stand a greater risk of a vehicle-bike collision. But it doesn't negate the fact quill stem is a risk - it is a poor design. With ease of height adjustment being the only advantage. Bearing preload adjustment, more rigid attachment and safer patent are all in favour of threadless stem/fork.

And yes - choosing lightweight components can be a risk. But there are not-lightweight threadless forks, bars and stems.

02Giant 

This, sums it up.

kbarch

Very interesting insight there. I'll concede that there are many times when such compromises (for lack of a better term) are necessary; however, there is often another solution that obviates such compromises, and it annoys me to no end when designers come up with arrangements that discard those solutions or intentionally defy the realities of construction.

As an architect, I work with designers who create some really cool looking spaces. From time to time, in order to achieve some "wow" effect, they'll throw in some architectural perversity like a floating stair, invisible door, or flaming waterfall. In building construction, such "magic tricks" don't usually result in the kind of sausage work we've been talking about here, but too often they do come at the expense of more important things like serviceability and harmonious, meaningful arrangements, and that's when I want to punch the designer.
(By the way, for sausage work in buildings, nothing beats prewar high-rises, with their slapdash terra cotta fire walls.)

79pmooney

Summed up well. Good engineering is not just designing the "best" but designing the best that can be built with what's available by the outfit that is going to build it. Good engineering often means wandering the shop floor and looking at the build process. Supervisors didn't like this and I couldn't always do it, but I tried to talk to the worker who was going to actually make the item/project I was designing. (Or his immediate manager who used to crawl into that space himself.)

I built fiberglass boats for several outfits including several custom boats and was an engineer in several design offices for large steel and fiberglass fishing boats and yachts.

Ben

topslop1

wanted one of these and couldn't afford it - glad i went somewhere else.

SethAZ 

I've been involved in 3D printing for a while now, and have designed some of my own things, some parts and improvements for my printer, things like that. Given the way the FDM (fuzed deposition manufacturing) version of 3D printing works, there are some things that are just plain difficult to print out cleanly. I've downloaded tons of 3D models that someone had uploaded to the popular 3D printing sharing sights, that looked awesome but were more or less unprintable. Just having a 3D model that can be converted into the STL file output that a 3D printer takes doesn't mean you're ever going to hold that cool model in your hand. At least in the world of 3D printing a successful designer has to be intimately aware of what's really possible, or what's at least easily and cleanly possible. It most definitely influences successful parts design.

Kontact 

The important point here is that we don't know if a BMC designer would find this acceptable or not. It just doesn't look like something any engineer would be in favor of.

SethAZ 

Yeah. And the funny thing is that Luescher, in the video, didn't really say what some people in this thread apparently think he said. He pointed out defects, didn't like how some things looked, and made some statements that certain things may or may not be OK depending on whether they were accounted for in the design, without ever actually stating that he felt they were or weren't accounted for.

I'm pretty sure the manufacturing processes have changed a lot in the last six years. It would be interesting to see a 2017 BMC cut apart and compared with this 2011-era frame to see how things look now.

If I were in the market for a carbon bike I'm not sure this video would influence me one way or another. I've ridden with a local guy here a few times who rides a very nice-looking BMC and neither of us has ever noticed any hint or whiff of trouble with it. I suspect they're actually fine, this ugly 2011-era sample notwithstanding.

BMC are still in business, and probably infinitely more people have direct experience riding with and on them than have seen this video. I think the correlation between those two facts is probably quite meaningful.

noodle soup

the the manufacturing process hasn't changed much, but that wasn't the problem here anyway. The problems here were in the execution of process(and some design issues).

duane041

So what's the over/under on this thread, like 35?

pdoege

I spent some time reading BMC's marketing pages and reviews for this frame.

They use "TTC (Tuned Compliance Concept) design and ISC (Integrated Skeleton Concept)". Whereby they claim to layer the fiber in different directions and thicknesses to get a ride that is compliant and stiff in the right places.

One review claimed that the frame was less expensive than the competition and was right at the UCI weight limits.

Given the video I can see how the folds near the seattube and stays could cause flex. It looks like the manufacturer got the flex and weight where they wanted it and then said, "good enough" to meet the price point.

Kontact 

That is what every carbon fiber bike maker does, going back to the Graftek.

Bah Humbug

Funny; I see it as a lack of critical thinking skills.

kbarch

I think it has gone on for pages because consensus is not the goal.
Sure, a manufacturer will establish it's own specifications for each quality, and there are industry standards, but others will look for something more ideal, meeting more stringent specifications or having additional qualities, which a manufacturer's specs may fail to meet or address.
No, we can't blame a manufacturer if their specs don't meet our own. I'd even go so far as to say we shouldn't worry too much about whether they meet their own, since we have no control over that, but we might worry more about our own qualities, and whether we meet our own specs.

Chandne

I really like the ride quality of my 2014 SLR01. Surprised to see the apparently lack of QC at BMC. I wonder if they will read/respond to this type of feedback. Eventually I'll switch out this frame but not sure with what...love the idea of Ti but need a climbing bike for those long days.

pickettt

If you all knew what your houses looked like behind the drywall........