IMHO it is not so much the material, but the people and processes assembling it. Big bike companies engineer the frames, then test prototypes exhaustively, train their operators, and presumably sample test to exert Statistical Process Control of the product quality. Some big companies produce reputable bike parts in C/F.
Little startups read a datasheet, put some resin and fiber together like building a surfboard with glass fiber, then ride it a couple hundred miles, then sell one. As soon as they can the designers pass the building function off to some guys they hire as cheaply as possible. Some little companies get hammered on internet by complaints.
I wouldn't trust a short run C/F front fork which if it breaks can ram your head into the pavement or stab your guts with the leftovers. The rest of the frame, well, I've fallen off a bike before. Below 25 mph falling off a bike doesn't hurt much, especially if I am wearing polyester long sleeve+pants Dickies, a helmet, poly gloves.
As for submersibles, C/F is super strong in tension when laid right. Submersible shells require a lot of compression strength. Two submersible operators told Rush to use steel or titanium. Then have it tested by a ratings agency. Cameron and another one. He didn't. Communications were private, as people that pronounce doom on products or services before any failures or defects occur can be sued in US or Canada for defamation.
Plus, commercial planes go through ultrasound crack tests of stress points at defined intervals. Even the aluminum skin ones: remember the de Havilland Comet. No news stories cover the results or frequency of crack inspections of the Oceangate craft.
Yeah, +1 on that. In fact, it's a concern I have with my (original owner) 1973 Raleigh Competition that I ride in New York. The bike is now 40 years old! Because it's acoustic and I'm old, it isn't put through anything like the punishment I used to inflict on it as a teenager and young adult. I would LOVE to run an ultrasound crack test on that frame at some point, as I hope to leave it to a friend's kid when I kick it.
I feel the same way about a Nireeka now as i did pre Titan disaster, the middrive has a great motor but the frame design combined with the fact that it is carbon fiber was huge NO WAY for me.
That's kinda what I mean. IMHO, that frame is experimental; who even knows where the stress points are? The original 250 watt hub drive appealed to me because the weight was lower at 47, and by selecting various options-- Magnesium fork, CF seat post, bats, etc.-- you could get it down to 44 or 45. I was pretty sure the Motobecane was about 49 out of the box, and I could get it down to 46 or 47 (which I did.) The cost was very similar, maybe the Nireeka was $200 more after selecting the options.
So then my choice was: A really cool-looking 45 pound bike that lacked the uphill capability of a mid-drive, or a 47-pound, more conventional-looking aluminum bike that would be better on steep hills. Certainly, another consideration was the possibility of stress to Nireeka's frame from rock strikes, or dumping the bike. My guess was that as a senior citizen, I wouldn't ride aggressively enough to dump the bike often, but that it would happen. And that did turn out to be the case-- I couldn't get the Moto up Hell Hill without laying it down on some of the early attempts, and I flipped it riding mad and stupid one night in late 2021.
There comparison between Ocean Gate and CF bike frames is a bit tortured. But I did read about Janet Kowal's accident is this outstanding, and fairly well-balanced article in Outside:
The high-tech material has been used to build frames and components for decades, but as bikes age, catastrophic failures are leading to lawsuits
www.outsideonline.com
One issue that comes up in this article is the issue of CF fatigue over time-- and we simply don't know how well some CF frames will hold up over 20, 30, 40 years-- though we have a much better idea than we did in 2018, when the article was written. I would probably be fine buying a CF bike from a major manufacturer, particularly now that the manufacturing process is more mature and my remaining lifespan is 5 to 25 years, but I don't think I'd sell it or put it in my will.
As for Titan, it's intriguing that she'd done 14 dives successfully on the Titanic. Maybe there was some component that was fine for 10 dives, but not 14.
The biggest issue with the Titan, is that there is apparently no experience on using CF for this kind of application and depth, it has not been tested and certified so far.
In addition, I heard they used some off the shelf component like the spherical dome window that was only certified for 1000 meters depth, and they were going to 3800 meters deep ....
I guess we may learn more if they decide to gather all the debris.
Some of the rescue missions are going to want someone to pay for their expenses ....
Yeah, I head this, too-- the bit about the dome window-- though I've been having trouble sourcing that. The implosion may have had nothing to do with the CF at all. Rated for 1300 meters?! That's only a third of the depth they intended to reach.
I confess to a certain distaste for movie people pontificating with their theories about technical issues outside their own field. But Cameron does have contacts in "the community" of deep ocean submersibles, and his thoughts on the accident, as reported in Insider, are chilling:
The filmmaker and Titanic expert James Cameron
told ABC Newsthat the Titan submersible was likely trying to resurface after losing all communications with the outside world hours into a deep-sea mission Sunday and that the five passengers on board likely knew of a problem before the vessel collapsed in a catastrophic implosion.
"This OceanGate sub had sensors on the inside of the hull to give them a warning when it was starting to crack," Cameron said on a Thursday appearance on ABC. "And I think, if that's your idea of safety, then you're doing it wrong."
"They probably had warning that their hull was starting to delaminate and starting to crack," he said.
"It's our belief, we understand from inside the community, that they had dropped their ascent weights, and they were coming up, trying to manage an emergency," Cameron added.
The last conclusion might be a bit dodgy-- apparently, Titan had dropped weights before on other dives when there was no emergency. We are still in the 'theories swirling' phase, but God, I hope they weren't descending faster than expected, or ascending in a situation where they knew they wouldn't make it-- basically, I hope they had no warning they were in trouble if they were in a situation where catastrophic failure was inevitable.
