chaadster

Yikes! Leuscher Technik just posted a cut-up video of a circa 2011 BMC Road Machine and the findings are distressing:

rpenmanparker 

Very informative. Scary. And it would have been useful to have shown us a really well done frame for comparison.

cb400bill

There are links in Youtube to other frames the guy cut open. Trek, Pinarello, Bianchi...

memebag

How many people did that bike kill in 6 years?

f4rrest

Is there an edited version for those of us who don't have all night to watch?

TL;DW

chaadster

Well, there’s that. It’s a fair enough reminder not to get carried away, but for me, I was more surprised that the BMC build quality could be so low, if only because of the brands premium rep and pro ranks presence. If it’s not built well, what are we paying for? Styling? The geometry? Hype? For me, it’s the worst indictment of carbon fiber because it not only exposes the lack of artistry and mastery in common CF construction, it reveals low quality masquerading as high quality. I would not be happy knowing I spent good money on that.

memebag

Maybe. Or maybe it doesn't matter if the insides are wrinkled. How did the bike ride? Was it fun to ride? Or was it horrible? Did it assplode a lot?

SethAZ 

I took a quick look at several other of his videos including some more frame cutups and a carbon wheel cutup. They all have lots of the same kinds of ugly things that are in the BMC cutup, though admittedly the BMC one just looks uglier. I guess the bottom line is that these things are laid up in a mold and then have compressed air blown into a baggy inside that presses the carbon fiber prepreg up against the mould. The process will make a nice looking appearance on the outside, but on the inside it's not going to be pretty. Lots of those videos show extra resin that's been squeezed up out of the prepreg and then hardened. It's probably a little better that it have a little more resin than it needs to completely filled the laminate, and have the excess squeezed out, than have places without enough resin and end up with voids or weak laminate. I'm no CF engineer so that's just my opinion looking at this.

But just remember these manufacturing processes are designed to make the bike functional and look good on the outside. You guys are looking at the man behind the curtain a little here. I'll assume that the products are actually OK until someone shows specific example of actual flaws in there with evidence supporting that that flaw will in fact lead to premature breakage, asploding, or whatever.

Racing Dan

Its not a question of the inside being "pretty" or not. The BMC had lots actual manufacturing defects. Including sanding too much, uneven wall thickness, wrinkling of the material and big voids in the laminate. That IMO indicates inadequate QC (or possibly they just dont care) and simply lack of skill. Is BMC even a real bike company or do they sell boxes build by some one else?

Imo not all of the other bikes are like that. Some maybe, but look at the Trek Emonda SL for instance. Much better execution.

Doctor Morbius

Wow. I think I'd rather take my chances with a Dung-Pu than with a BMC now.

79pmooney

Seth, vacuum bagging can be done that leaves a clean laminate surface, but it takes skill and attention. (I used to build boats. We did far bigger vacuum jobs. I've also sailed those boats in situations where my life was dependent on those boats holding together. I developed a simple philosophy - I will only go to sea on good boats by design, cared for, readied responsibly to go to sea and with good sailors. I am not as fastidious about bikes, but a real part of that philosophy overlaps into what bicycles I will own. And they will never be female mold plastic.

Not all shoddy workmanship is carbon fiber. I bought an old 531 Raleigh. Loved its ride, especially off pavement. But I didn't trust its workmanship so I had a local framebuilder send it to have the pain stripped, then inspect it. It seemed to have missed the brazing step when it was made. He did a lot of work to make it a good, trustworthy bike. It now passes the test I used to use for boats.

Ben

kbarch

Regardless of whether there's any real risk or difference in serviceability, this is why I'd like my next CF frame to be assembled from tubes. Visited the Casati workshop last May and saw what they worked with - beautiful materials, meticulously assembled. A finished bike from such a workshop is like a Brioni suit compared to the pair of sweats that some CF bikes are.

znomit

Hmmmm....

trailangel

^^ I guess BMC doesn't have a cinematographer that knows anything about lighting either, judging from that Youtube video.

chaadster

Exactly.

Furthermore, I think several people don’t understand that this frame has particularly bad quality issues. Yes, most bikes using this construction will exhibit some of these imperfections, but it’s rare to see so many and to such an extent. Raoul himself expressed incredulity and disappointment inspecting this bike.

A question I have is whether this BMC could be a counterfeit. I’ll add that question to the video comments (if it’s not been asked yet) and see if he has any thoughts on the possibility.

chaadster

Impec is not what we’re talking about here...except that Impec was created to address exactly the problems of QC the RM 01 displays.

rpenmanparker 

Interesting take. Did you see tubes and lugs cut open to show how consistently they were laid up, compressed and cured? Did you see a finished frame cut open to show how uniformly the tubes were bonded to the lugs?

BillyD

I think I'd rather take my chances with metal.

memebag

The questions I have are:

1. How many miles was this bike ridden?
2. Did it fail during those miles?

If it provided a good ride for some large number of miles then I have to conclude that these defects and/or irregularities weren't important in this case.

If you cut me open you'll see a bunch of wrinkles and voids, too.

kbarch

I saw the loose, individual tubes before they were assembled, which were absolutely perfect - I don't know how they are made (not at their shop), but they looked as smooth and uniform as extrusions, inside and out.

The connections aren't lugged in the conventional way: funny as it sounds, it's more like they are glued and taped together. The ends are precisely cut, prepped, then joined and taped over with carbon fiber fabric. We saw connections in varying stages of completion, and amazingly the finished product was so carefully executed that one can finish it with a clear coat - it all looked like one continuous weave. Sublime.

The nice thing is, although they are expensive, they are not extraordinarily so. Because they are assembled from cut tubes, made to measure is a no-brainer, and less expensive than (or at least competitive with) higher-end off-the-rack frames.

chaadster

Totally valid questions, the answers to which I’d like to know myself. It did wind up at Luescher Teknik, though, and went through ultrasonic examination before the cutup, so the odds are there was a suspicion of damage.

However, the answers to the questions you propose are immaterial to the issue of quality production and workmanship. It should go without saying that the bike was obviously not built to design specs, as no one designs-in integrity compromising voids, material folds, inufficient compaction, or improper lamination. One may design to accommodate variances in production accuracy, but that is exactly the essence of quality.

This is not a quality made frame, regardless of mileage or any possible failure.

chaadster

This sounds like the same production method used by Sarto and Titici in Italy, and also Crumpton in the USA. It's a method which produces a slightly heavier frame than bladder monocoque construction, but avoids many of the problems of the latter.

Monocoques can be fine, of course, but to be really good they have to be done right. Probably a lot of the freak accidents, like where my clubmate’s carbon Felt gravel bike fell over and cracked its chainstay hitting a coffee table, are exacerbated by the kinds of quality issues seen in this RM01. That’s not to say the Felt was low quality, only that conditions where material is thinner than it should be, or improperly bonded or malformed, would be expected to be less strong than it would otherwise be.

ridelikeaturtle

When I see a video like this one, it makes me even more smug about my titanium and steel bikes.

memebag

I don't know much about carbon fiber manufacturing (just what I see on "How It's Made", really), but my questions matter because if carbon fiber bikes can look like that inside and still perform their desired function, then looking at wrinkles and voids doesn't reveal anything useful. For all I know there are visual horrors inside my aluminum bikes, but as long as the bikes work the horrors are irrelevant.

chaadster

I don't know if you don't understand quality or if you reject the idea of quality, but either way, it's a poorly defensible position to be in.

Using your example, your alu bikes "work" only under your specific conditions. What if the rider were 100kg heavier? What if the rider could spike power north of 2k watts? What if the road conditions were rougher? What if the riding was wet coastal? What if the ride volume was double? What if the conditions were any mix of those differences? Would a low build quality version of your alu bike last as long as a high quality build version?

Please don't attempt to answers those questions, because they're rhetorical, and the answers don't matter. What matters is understanding that a frame that's not as strong as it could be (because of voids, uneven material thickness, improper compaction, delamination, etc.) is not as good, though it may be serviceable.