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Comment by faeriechangling | Hacker News Reader

I make a distinction between "Plastic" and "Carbon Fibre Reinforced Polymer with a magnesium roll cage" that this laptop uses.

We don't think an aluminium bike is better than a carbon fibre bike, so why is an aluminium laptop better than a carbon fibre laptop? I mean aluminium has some nice advantages like heat dissipation but CFRP allows for much lighter laptops. If anything I prefer CRFP because of the weight advantages and because it's more of a "sleeper" material when laptops are VERY tempting for thieves.

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Aluminum for me is a big no-no considering that I always get static discharge from them.

I also distinctly remember the unnerving feeling of getting a tingling sensation on my wrists when having a macboook pro charging connecting to mains.

I have only used them when clients specifically request it, but otherwise connect them to a workstation of my choice.

Oh, I'm glad I'm not the only person who noticed this - several job laptops (macbooks) have definitely done this to me as well. It's subtle, like your wrist is sticky or being tapped rapidly, but the moment you yank the mains power out from the machine it goes away. Very unsettling (and escalates to painful at times).

I used to experience this as well, on multiple MacBooks across years. It seems to have disappeared when I moved to a non-MagSafe USB-C charging generation of MacBooks (can't say for the latest ones though).

Yeah I had that with MacBooks which are brand new.

Feels like a static electrical layer. But after some time it’s gone

It is because it is not grounded. The leakage current then goes into the case.

Unfortunately it seems to be quite difficult to buy grounded usb-c chargers. Most of them seem to come with C7 cables with no ground.

Grounding doesn't make much sense for devices which are completely plastic encased.

I get your point about "pass-through grounding" to the laptop, but then again, a lot of time the laptop is not connecting to a charging wire anyway.

The problem is - laptops used to have their own dedicated chargers. And generally speaking, they were grounded. Now we're moving to usb-c though, it means we've lost it being grounded. And many laptops are made of conductive materials so therefore it is an extremely minor annoyance and downside of usb-c.

Also, I'm in the UK with its crap ring circuits packed with 240v/13amps. I'd rather have a ground when I'm one fault away from 3000 watts momentarily being delivered to my lap. Especially with these exciting new GaN chargers and their open circuit failure modes..

My understanding is that all chargers, GaN or not, are required to use a transformer to electrically separate the primary (wall input) from the secondary (charger output). So a fault directly connecting you to the wall circuit should not be possible with an authentic charger.

> We don't think an aluminium bike is better than a carbon fibre bike

Depends on how you define better. Carbon bikes are prone to catastrophic failure, and if you fall often are a bad idea. Of course, you might just say "just don't fall".

Yes, honestly, a good aluminium frame is preferable to carbon for 90% of people. The small tradeoff in weight and vibration/stiffness characteristics is really not worth the loss in structural integrity, money, and peace of mind.

Modern carbon frames are designed with structural integrity in mind, the frame-building process allows more fine-tuning than aluminum. Aluminum's best quality is it's value, you can wreck one and buy another and still have spent less than a low-grade CF frame.

Not quite. Carbon fiber is a composite. Structural integrity is not one dimensional, and while carbon fiber frames are great in their intended loads, they are bad in puncture and abrasion, and that is inherent to carbon fiber.

It is so much easier to wreck a carbon fiber frame than an alu frame. It just takes one pointy rock or one bad slide. Whereas an alu frame will only receive cosmetic damage

That's a nuanced point to draw, thank you; most of my wrecks have been head-on, or from the side.

I can patch my fiber frame though, it's getting harder to "total" them nowadays imo. I've tried!

I see - I definitely haven't been keeping up that hard, so I may be surprised by recent improvements :)

Out of curiosity, do you have any sources with actual evidence that carbon fiber is prone to catastrophic failure in bike frames/components, particularly compared to aluminum? From my (rather limited) research, there seems to be plenty of speculation and anecdotes online about the fragility of CF, but not much actual evidence of rates of catastrophic failure. My impression (not based on expertise or much evidence) is that properly designed CF is much stronger for a given weight than most metals, but can fail at relatively low loads if stressed in a way it wasn't designed for. As it applies to biking, I guess this would tend to mean that CF bikes are more likely to be structurally damaged because of a crash/fall, but not necessarily more likely to fail and cause a crash/fall. This of course supports your point that CF is not a good choice for someone who falls often.

> Now that use of the material, once reserved for high-end bikes, has become widespread in the bike industry, reports of accidents and mysterious failures are on the rise.

> Reed and other experts in carbon fiber agree that any material can fail. Wrecks happen from faulty aluminum, steel, and even rock-hard titanium. The difference with carbon fiber is that it can be difficult to detect signs of damage that might signal imminent failure. Cracks and dents in other materials are typically easy to see, but fissures in carbon fiber often hide beneath the paint. What’s worse is that when carbon fiber fails, it fails spectacularly. While other materials might simply buckle or bend, carbon fiber can shatter into pieces, sending riders flying into the road or trail. And this kind of catastrophic destruction can happen to any part of a bike made with the material.

> “It’s completely reasonable for someone who wants a lightweight bike to look at carbon fiber, but they need to understand the risks,” Elrath says. “Absolutely this is getting ignored.”

https://www.outsideonline.com/outdoor-gear/bikes-and-biking/...

There are plenty of videos from competitions where the carbon suddenly fails. I've never seen that with aluminum bikes. Last three accidents from 4:15:

https://www.youtube.com/watch?v=kpeTiF_Tm04

But going back, if one is not racing, is it really worth the extra risk for minor performance improvements? Some say that after any serious fall/crash a carbon frame/component should be replaced because it's difficult to assess if it was damaged or not. How many can afford that?

I was hoping for some actual data. As I mentioned there's plenty of anecdata online, but I don't know if anyone has really studied this. The article you linked to suggests that nobody has done a systematic study.

As a counterpoint to the video you linked, I'm reminded of this video of Danny Macaskill having to work pretty hard to break a carbon rim: https://www.youtube.com/watch?v=VfjjiHGuHoc

> ... if one is not racing, is it really worth the extra risk for minor performance improvements?

It really depends on how much extra risk there is and how much the rider values the performance improvements. Without actual data about the (relative) risk of carbon fiber failure in bike components, we have to guess based on the information we have avaliable. Most of this seems to either be anecdotal, or coming from from interested parties, e.g. bike manufacturers, lawyers who make their living suing bike manufacturers, and journalists who are probably more interested in writing about something exciting happening than something exciting not happening. My impression is that the relative risk of of using carbon fiber in some (but perhaps not all) bike components is pretty small compared to the other risks involved in biking, and the performance improvements are big enough to be worth it for me, even though I don't race.

Aluminum bikes are just as prone to failure, and in fact are less likely to be left in a repairable state after an accident. A dent or a crack in the frame ofter renders it useless.

True of carbon as well, but they can be repaired in some cases; aluminum frames almost always need to be scrapped.

Re: bikes, I've found most CF frames lack fender/rack mounts. If you want utility (commuting, shopping, travel), aluminum is going to win out. For example, I can't think of a single CF cargo bike.

My username may give this away, but after tens of thousands of miles ridden on a variety of frames, I've settled on chromoly steel as the most versatile material. In fact I just picked up another steel frame bike this past weekend with a rack for panniers and a fork that can fit gravel tires.

Regardless I find it very strange to compare a laptop with a bicycle. You would pick the materials when constructing either one for very different reasons.

Specialized Diverge does have fender/rack mounts (although you need to replace the stock seat post clamp with another one for the top rear rack mounts, but Spec does sell one). It's not exactly a utility bike, but for touring around civilized Europe it's a very good bike. :-)

> why is an aluminium laptop better than a carbon fibre laptop?

It looks nice.

Which is completely subjective, of course, and purely about aesthetics. But for a personal item like a laptop, I think aesthetics are much more important than HN comments would let you believe.

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