The empire of C++ strikes back with Safe C++ proposal
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    56m ago 100%

    On one hand, I'm pleased that C++ is answering the call for what I'll call "safety as default", since as The Register and everyone else since pointed out, if safety constructs are "bolted on" like an afterthought, then of course it's not going to have very high adoption. Contrast this to Rust and its "unsafe" keyword that marks all the places where the minimum safety of the language might not hold.

    On the other hand, while this Safe C++ proposal adopts a similar notion of an "unsafe" context, it also adds a "safe" keyword, to specify that a function will conform to compile-time safety checks. But as the proposal readily admits:

    Rust’s functions are safe by default. C++’s are unsafe by default.

    While the proposal will surely continue to evolve before being implemented, I forsee a similar situation as in C where code that lacked initial const-correctness will struggle to work with newer code and libraries. In this case, it would be the "unsafe" keyword that proliferates everywhere just to call older, unsafe code from newer, safe callers.

    Rust has the advantage that there isn't much/any legacy Rust to upkeep, and that means the volume of unsafe code in Rust proframs is minimal, making them safer overall today. But for Safe C++ code, there's going to be a lot of unsafe legacy C++ code and that reduces the safety benefit for programs overall, for the time being

    Even as this proposal progresses, the question of whether to start rewriting some code anew in Rust remains relevant. But this is still exciting as a new option to raise the bar in memory safety in C++.

    4
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearMI
    Jump
    Public service news agency falsely stating that most accidents with pedelecs are fatal. Statistics they cite say it's 0.8%
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    10h ago 100%

    My literacy of the German language is almost nil, but it seems patently unreasonable for an author or journalist to believe that over half of the incidents involving a fairly common activity would be fatal. Now, I should say that I'm basing this on prior knowledge of the German e-bike/pedelec market, where over half the bikes sold there at electric. What this implies is that of the sizable population of the country, of the subset which are riding bicycles, and further the subset which ride pedelecs, and still yet the subset which get into a collision or other incident, that somehow it's believable that over half will die?

    That cannot possibly be true, does not pass the sniff test, and isn't even passable as a joke. If it were true, there would be scores of dead riders left and right, in every city in the country, daily. I suspect it would overtake (pun intended) the number of murders in the fairly safe country.

    Compare this with parachuting, which would be more sensible for a headline of "most accidents are fatal", I'm shocked that no one in the publication chain of command noticed such a gross error. While it's true that some statistics are bona fide shocking -- American shooting deaths come to mind -- this is a very bizarre instance of confirmation bias, since no one noticed the error.

    I was led to believe that cycling in German is "normalized but marginalized", but this type of error speaks to some journalistic malpractice.

    4
  • store.steampowered.com

    Skateboard tricks but with cars! A colleague of mine has been working on this game for a while, streaming his progress [on Twitch](https://twitch.tv/djoslin0). No firm release date but it can be wishlisted on Steam though. > Become a master of physics by launching your car into the air, performing kickflips, and grinding rails. Complete missions to unlock levels and cosmetics, practice tricks until perfection, or just goof around with friends.

    3
    1
    photo.walgreens.com

    When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences. I have not yet claimed this offer, but because it expires in less than 2 hours from now, I figured it made more sense to post this earlier than later. ~~It may be possible to also claim from the Walgreens mobile app, but I haven't tried that either.~~ Nope, the code doesn't work on the mobile app; desktop only.

    -1
    0
    https://www.cvs.com/photo/create/builder?sku=CommerceProduct_7182&category=prints

    You must have exactly two 5x7 glossy prints in your cart for the code to apply. When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    1
    0
    https://photo.walgreens.com/store/design-catalog?ptype=cards&sku=CommerceProduct_125921

    Use the code on the Walgreens app plus the website to claim the same offer twice! You must have exactly two 5x7 glossy prints in your cart for the code to apply. When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    0
    0
    What happens when the US runs out of SSNs?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    1w ago 96%

    This does not agree with what the Social Security Administration has published:

    Q20: Are Social Security numbers reused after a person dies?

    A: No. We do not reassign a Social Security number (SSN) after the number holder's death. Even though we have issued over 453 million SSNs so far, and we assign about 5 and one-half million new numbers a year, the current numbering system will provide us with enough new numbers for several generations into the future with no changes in the numbering system.

    25
  • What is the stock market?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    1w ago 100%

    For the historical questions, I don't really have answers, especially where it involves departures from the Western world. I did, however, briefly touch up on Islamic banking, which I've always found intriguing as the Islamic faith does not permit charging interest on loans, viewing it as usurious. I'm informed that Christianity also had a similar prohibition on usury, but apparently it fell due to the need to fund the constant wars in Europe.

    I'm not really seeing the difference in feudalism except a members only kind of participation with a crony pool of inbreds, not all that different than the billionaires of today.

    I think the important distinction insofar as stock markets is that the crony pool of inbreds have access, but so too does the commoner. Well, the middle-class commoner usually. And we've seen David-vs-Goliath cases where the commoners put up a decent fight against the inbreds' institutions; the whole GameStonk fiasco comes to mind. An equivalent economic upset would have been wholly impossible at any point during any feudal period in history.

    What are the idealist or futurist potential alternatives between the present and a future where wealth is no longer the primary means of complex social hierarchical display? My premise is that basing hierarchical display on the fundamental means of human survival is barbaric primitivism.

    From conversations I've had previously, possible answers to that question are presented in the works of Paul Cockshott, author of Towards A New Socialism. I've not read it, but friends in Marxist-Leninist parties have mentioned it. The Wikipedia page, however, notes that it's an economics book, which could be fairly technical and difficult to read. Sort of like how Das Kapital is more-or-less a textbook, in contrast with how Wage Labour And Capital was meant for mass consumption.

    Wealth extraction neglects the responsibility of the environment and long term planning.

    True. The cost to the environment is not "internalized", to use the technical term. Hence, it doesn't need to be paid for, and is thus "free real estate". Solutions to internalize environmental harm include carbon taxes or cap-and-trade. But the latter is a lukewarm carbon tax because it only looks at the end-result emissions, rather than taxing at the oil well, so to speak.

    I'm curious how humanity evolves in a distant post scarcity future but without becoming authoritarian or utopian/dystopian

    Might I recommend The Three-Body Problem and the trilogy overall by Liu Cixin? This phenomenal hard scifi work describes a space-faring future where the human species faces a common, external threat. After all, much of today's progress was yesterday's scifi. So why not look to scifi to see what tomorrow's solutions might be. It's no worse than my crystal ball, which is foggy and in need of repair.

    2
  • What careers are relatively easy to get into with decent unions behind them?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    1w ago 100%

    If you're in the USA, I cannot understate how useful it may be to refer to the US Bureau of Labor Statistics's (BLS) Occupational Outlook Handbook (OOH), a resource which I believe has no direct comparison:

    How can I learn about an occupation that is of interest to me?

    The Occupational Outlook Handbook (OOH) provides information on what workers do; the work environment; education, training, and other qualifications; pay; the job outlook; information on state and area data; similar occupations; and sources of additional information for more than 300 occupational profiles covering about 4 out of 5 jobs in the economy.

    As for answering the question, anecdotal conversations I've had suggest that the trades (eg glazier, electrician, plumber) in the USA are promising fields, since while the nature of the job might change with different needs, people still require electric wires and piped water. But the OOH could give you more specific outlooks for those specific trades.

    I was once told that plumbers can make very serious sums of money, even if they're only ever installing supply-side piping. That is to say, the plumbing for water supply, as compared to drainage or sewer pipe, which are generally perceived as less appealing.

    20
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearTA
    Jump
    The salesman and the utterly unusable search feature
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    1w ago 100%

    For the benefit of everyone else who didn't recognize the initialism ERP, I think it's Enterprise Resource Planning software, which seems to be a suite of applications for managing a sizable business.

    11
  • What is the stock market?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    1w ago 100%

    I'll take a shot from the hip at this question, but note that I won't add my customary citations or links.

    The stock market is the paragon of property and trusts, contracts, corporations and law, and the capitalist socio-economic system. The very existence of the stock market implies a society that has some or most of these concepts.

    For example, for shares to be traded, there generally must exist ownership rights upon the shares, distinct from the ownership rights that the company has of its own property. Or if not outright ownership of a share, then the benefit that a share provides (eg dividends). It also implies a legal system that will enforce these rights and the obligations of the company to its shareholders.

    For a tradable company to exist, it must be organized/chartered as an entity distinct from any single person. This is different than the feudal days, when ventures would be undertaken "in right of the King" or some member of the nobility. The feudal method wouldn't work for modern companies, or else the King/Duke/Count/whatever could stiff the shareholders by just taking all the earnings. The company still needs to be created by legal means, either an Act of Parliament/Congress, by letter patent from the Monarch, or the modern administrative method of applying to the state Secretary of State (USA) or Companies House (UK) as examples.

    Even the structure of a for-profit tradeable company -- when compared to a state-owned enterprise, a non-profit, a co-op, or an NGO or QUANGO -- is a representation of the values inherent to capitalism. A company is obliged to use the shareholders' funds -- which is held by the company but is owed to the shareholders -- to extract the greatest return. But this can come in many forms.

    Short-term value from buying investments and quickly flipping them (eg corporate home buyers) is different than rent-seeking (eg corporate landlords) and is still different than long-term investments that actively work to build up the value (eg startup incubators, private wealth funds, Islamic banking, transit-owned adjacent property). If a for-profit company doesn't have a plan to extract a return... they're in hot water with the shareholders, with penalties like personal liability for malfeasance.

    Another way of looking at the stock market is that if you have all the underlying components but don't yet have a stock market, it would soon appear naturally. That is to say, if the public stock markets were banned overnight, shares would still trade but just under the table and without regulation. But if any critical part underpinning the markets stopped existing, then the market itself would collapse.

    History shows numerous examples where breakdowns of the legal system resulted in market mayhem, or when corporate property is expropriated for the Monarch's wars or personal use, or when funds invested into or paid out of companies is hampered by terrible monetary inflation.

    As for what the stock market does, its greatest purpose is to organize investments into ventures. Historically, ventures were things like building a ship to sail to the New World and steal obtain goods to sell at home. Merchant ships were and are still very expensive, so few singular persons could afford it. And even if the could, the failure of the venture could be catastrophic for that person's finances. Better to spread the risk and the reward amongst lots of people.

    What was once the sole domain of the landed gentry and nobility, slowly opened to the nouveau riche during the Industrial Revolution(s), then in turn to everyday people... for better or worse. It's now almost trivial to buy a share in any particular listed company, but just opening the stock market to everyone would have been chaotic at best. I think it's NYSE that still has on-floor traders/brokers, but imagine if all shares in that market had to be traded in a single room, with no digital trading. It's already quite lively on the trading floor today, now add all the trades from middle class Americans on payday. It would become physically impossible.

    Likewise, a pure capitalist stock market would permit awful things like bribing journalists to write fake stories to crash a stock, then buy it for cheap. Or pump and dump scams. And would have no "circuit breakers" that halt a share during so-called flash crashes.

    I'm reminded of a scene from the ITV show Agatha Christie's Poirot in the episode "Appointment With Death", where a wealthy woman is not only murdered but her business empire collapses because the murderer also spooks the markets as a double whammy, causing investors to panic and sell up. The relevant implications here is that despite her company not having changed its financial picture, it got cut up for scrap and thus lost most of its value, rendering the business worthless in the end. Companies are usually valued more as a going-concern, above what all its property put together would amount to. Where does that additional value come from? It's the prospect of a return from this particular assemblage of resources.

    Suffice it to say, the stock market is a lot of things. But I view it as a natural result of certain other prerequisites, meaning we can't really get rid of it, so instead it should be appropriately regulated.

    8
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearMI
    Jump
    Watch: How DJI pulls massive torque out of its tiny ebike motor
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    2w ago 100%

    I think you're spot on, since using a random power/torque/rpm calculator online, an 85 Nm mid-drive motor rotating at a reasonable crank cadence of 80 RPM yields a power output of 710 W. That's just shy of the max power regulation in the USA for ebikes, at 750 W. And motors can definitely go faster than 80 RPM.

    Mid-drive motors could probably be built with even more torque, but because electric motors maintain near-constant torque through most of their RPM range, the motor controller would have to perform more current limiting at the higher RPMs to stay under the legal power limits. So there's less benefit, unless someone really badly wants more low-RPM torque.

    At that point, though, other parts of the bicycle drivetrain might start disintegrating under such forces.

    4
  • If the Federal Government wanted to make a new planned city, would they be able to use Eminent Domain?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    2w ago 100%

    From an urban planning perspective, there are some caveats to your points:

    A new downtown would make a subway very easy and cheap to build, you could cut and cover instead of tunnelling

    Cut-and-cover will make shallow underground tunnels cheaper to construct in almost all cases irrespective of building in an old city center or as part of building a new city center from scratch. In fact, older pre-WW2 cities are almost ideal for cut-and-cover because the tunnels can follow the street grid, yielding a tunnel which will be near to already-built destinations, while minimizing costly curves.

    Probably the worst scenario for cut-and-cover is when the surface street has unnecessary curves and detours (eg American suburban arterials). So either the tunnel follows the curve and becomes weirdly farther from major destinations, or it's built in segments using cut-and-cover where possible and digging for the rest.

    Cheeeaaap land for huge offices, roads, and even houses

    At least in America, where agricultural land at the edges of metropolitan areas is still cheap, the last 70 years do not suggest huge roads, huge offices, and huge house lead to a utopia. Instead, we just get car-dependency and sprawl, as well as dead shopping malls. The benefits of this accrued to the prior generations, who wheeled-and-dealed in speculative suburban house flipping, and saddled cities with sprawling infrastructure that the existing tax base cannot afford.

    Green field is just so cheap.

    It is, until it isn't. Greenfield development "would be short term appealing but still expensive when it comes to building everything". It's a rare case in America where post-WW2 greenfield housing or commercial developments pay sufficient tax to maintain the municipal services those developments require.

    Look at any one municipal utility and it becomes apparent that the costs scale by length or area, but the revenue scales by businesses/households. The math doesn't suggest we need Singapore-levels of density, but constant sprawling expansion will put American cities on the brink of bankruptcy. As it stands, regressive property tax policies result in dense neighborhoods subsidizing sprawling neighborhood, but with nothing in return except more traffic and wastewater.

    Either these cities must be permitted to somehow break away from their failed and costly suburban experiments, or the costs must be internalized upon greenfield development, which might not make it cheap anymore.

    1
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearDI
    DIY 3w ago
    Jump
    Gate problems
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 100%

    Looking at the images you've attached, this appears to be an 8 ft wide by 6 ft tall fence. That's a good amount of weight in just the wood, and there isn't any part of the design that diagonally braces the frame, except the steel cable... which tore from its mounts.

    My layman's view is that you absolutely need diagonal wood elements, which should only be installed after unloading the fence, either by removing the boards or by propping up the wheel-end so the frame returns to being squared. If the wheel interferes with this, remove it for the time being.

    wide wood fence with diagonal bracing

    But I think you'd still need the steel cable, and if that has broken from its originally designed mooring, then this gate is already compromised. You may have to start over with a new Adjust-A-Gate kit or repair the current one so the cable will mount to the steel parts, rather than the wood.

    I would say to rectify the diagonal supports first, before doing anything with the hinges, since if the hinges were actually the root problem, this gate would have already fallen over. That said, it seems to me that such a wide gate might have called for more substantial hinges.

    The other commenter's suggestion to consider a pair of less-wide gates is also sound, if the goal is a minimal-fuss gate that will last at least a decade of additional sagging and weather.

    4
  • Weird PC PSU Capacity
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 100%

    commercial appliances didn’t take any stand-by measures to avoid “keeping the wires warm”

    Generally speaking, the amount of standby current attributable to the capacitors has historically paled in comparison to the much higher standby current of the active electronics therein. The One Watt Initiative is one such program that shed light on "vampire draw" and posed a tangible target for what standby power draw for an appliance should look like: 1 Watt.

    A rather infamous example of profligate standby power was TV set-top boxes, rented from the satellite or cable TV company, at some 35 Watts. Because these weren't owned by customers, so-called free-market principles couldn't apply and consumers couldn't "vote with their feet" for less power-hungry set-top boxes. And the satellite/cable TV companies didn't care, since they weren't the ones paying for the electricity to keep those boxes powered. Hence, a perverse scenario where power was being actively wasted.

    It took both carrots (eg EnergyStar labels) and sticks (eg EU and California legislation) to make changes to this sordid situation. But to answer your question in the modern day, where standby current mostly is now kept around 1 Watt or lower, it all boils down to design tradeoffs.

    For most consumer products, a physical power-switch has gone the way of the dodo. The demand is for products which can turn "off" but can start up again at a moment's notice. Excellent electronics design could achieve low-power consumption in the milliwatts, but this often entails an entirely separate circuit and supply which is used to wake up the main circuit of the appliance. That's extra parts and thus more that can go wrong and cause warranty claims. This is really only pursued if power consumption is paramount, such as for battery-powered devices. And even with all that effort, the power draw will never be zero.

    So instead, the more common approach is to reuse the existing supply and circuitry, but try to optimize it when not in active operation. That means accepting that the power supply circuitry will have some amount of always-on draw, and that the total appliance will have a standby power draw which is deemed acceptable.

    I would also be remiss if I didn't mention the EU Directives since 2013 which mandate particular power-factor targets, which for most non-motor appliances can only be achieved with active components, ie Active Power Factor Correction (Active PFC). While not strictly addressing standby power, this would be an example of a measure undertaken to avoid the heating caused by apparent power, both locally and through the grid.

    4
  • photo.walgreens.com

    Use the code on the Walgreens app and the website to claim the same offer twice! When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    2
    0
    Weird PC PSU Capacity
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 100%

    How were you measuring the current in the power cable? Is this with a Kill-o-watt device or perhaps with a clamp meter and a line splitter?

    As for why there is a capacitor across the mains input, a switching DC power supply like an ATX PSU draws current in a fairly jagged fashion. So to stabilize the input voltage, as well as preventing the switching noise from propagating through the mains and radiating everywhere, some capacitors are placed across the AC lines. This is a large oversimplification, though, as the type and values of these capacitors are the subject of careful design.

    Since a capacitor charges and discharges based on the voltage across it, and because AC power changes voltage "polarity" at 50 or 60 Hz, the flow of charge into and out of the capacitor will be measurable as a small current.

    Your choice of measuring instrument will affect how precisely you can measure this apparent power, which will in-turn affect how your instrument reports the power factor. It can also be that the current in question also includes some of the standby current for keeping the PSU's logic ICs in a ready state, for when the computer starts up. So that would also explain why the power factor isn't exactly zero.

    5
  • Squatober is starting!
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 100%

    An outside description of Squatober: https://www.garagegymreviews.com/squatober

    I like the concept of a month-long squat fitness challenge but I personally don't jive with the notion of having to follow two Instagram accounts daily to get the next day's program description. My life requires a bit more advance notice than that.

    6
  • RNOP ADLH
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 72%

    Agreed, it's a very bad design. If your school speed limit covers most of the daylight hours on weekdays, is the implicit suggestion that it's fine to drive faster on weekends and during nighttime? The street should be rebuilt to enforce the desired speed limits, not with paint or signs.

    Oh, we're talking about the letters on the glass. My bad lol

    5
  • Question: dies anyone here do restoration?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 100%

    You may want to include a photo of the piece, ideally many photos from various angles.

    But to be frank, unless you find someone within a max 1 hour's travel distance, it's not likely someone will be found who is also willing to take on this project. Wood furniture is, for all its pros and cons, heavy.

    11
  • Good Computer Handbooks
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    3w ago 100%

    A few months ago, my library gained a copy of Cybersecurity For Small Networks by Seth Enoka, published by No Starch Press in 2022. So I figured I'd have a look and see if it it included modern best-practices for networks.

    It was alright, in that it's a decent how-to guide for a novice to set up sensible, minimum network fortifications. But it only includes an overview of how those fortifications work, without going into the additional depth needed to fine-tune or optimize them for specific environments. So if the reader has zero experience with network security, it's a worthwhile read. But if you've already been operating a network with defenses for a while, there's not much to gain from this particular text.

    Also, the author suggests that IPv6 should be disabled, which is a terrible idea. Modern best-practice is not to pretend IPv6 doesn't exist, but to assure that firewalls and other defenses are configured to handle this traffic. There's a vast difference between "administratively reject IPv6 traffic in/out of the WAN" and "disable IPv6 on all devices and pray no one ever connects an IPv6-enabled device".

    You might have a look at other books available from No Starch Press, though.

    6
  • Do you think I can fit 38mm tires on my bike?
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    4w ago 100%

    Other commenters addressed some of the possible clearance issues, where a wider tire might interfere with the frame. But it seems to me that the discussion on tire/rim compatibility can be fleshed out.

    To lay some background, a bicycle tire is essentially mostly a hollow rubber donut, but with the inward-facing "donut hole" walls supported instead by a pair of co-axial steel hoops, known as the beads. Thus, the beads define the inner diameter of the tire. When a tire is inflated, the air pressure will cause expansion in all directions. The tire's beads and walls (ie casing) will hold their shape, but the air pressure will try to push the two beads apart. This is where the rim walls come into play: the rim walls prevent the beads from widening apart. With the air pressure fully contained in all directions, the wheel assembly can now support impressive loads relative to the weight of the rubber and metal.

    bicycle tire cross section

    So for a bicycle rim and bicycle tire to be compatible, the two most basic criteria must be met:

    • the tire's bead diameter must exactly match the rim's "seated" diameter, ie at the bottom of the rim walls
    • the beads must fit within the rim walls, being neither too narrow or too wide, such that the tire maintains its correct shape and that normal loads will not cause the beads to slip out of the rim walls

    The first criteria is a strict match, so that's easy to check. But the second criteria has some allowance for different tire widths on a given rim, or different rims for a given tire width. We can now look at what rims you have, and whether they're compatible with your preferred tires.

    It looks like your rims are Weinmann DP18 rims, which have a trade diameter of 700C and the narrowest part of the rim walls are 12.40 mm apart. I say "trade diameter" because no part of the rim actually measures 700 mm. Instead, rim/tire compatibility can only reliably be calculated using the ISO/ETRTO measurements, which are a pair of numbers that directly answer the two compatibility criteria from earlier.

    The first number in the ETRTO system is the inner rim width, and the second number is the bead seat diameter, both in millimeters. So your rims would be universally identified as 12-622 or 13-622, since 622 mm is the actual circumference if you put a tape measure around the rim. The first number can be 12 or 13 because 12.40 mm could round up or down. Sub-mm precision does not substantially matter here.

    Now we can look at your desired tires, which have a trade designation of 700x38c but they also give the ETRTO measurement of 40-622. Unlike rims, the trade designation does actually convey some measurable dimension of the tire, but these are irrelevant for tire/rim compatibility. See the spoiler below for more.

    ::: spoiler fuller explanation of tire trade designations In this case, 700 mm is the approximate outer diameter of the tire, which is only useful if:

    • you're setting up your bike computer's speedometer (bigger diameter means more distance per wheel revolution)
    • or you need to calculate the wheel's ground clearance or its clearance to the forks

    Also, 38 mm is the approximate width of the tire when inflated. This is allowed to differ from the ETRTO width, since balloon tires on MTB bikes can be substantially wider than the rim, and road bike tires can be narrower than the rim. This width is mostly only useful to check the clearance between your forks, although it's also useful to know if you're riding near streetcar tracks.

    Narrow tires can get caught in the groove along the tracks, whereas wider tires can glide over them. A skilled rider can navigate tracks with any tire width, but it's still a hazard that needs to be identified and negotiated. :::

    So we now know the rim is 13-622 and the desired tire is 40-622. Checking the first criteria, we see that the diameters (622 mm) are a perfect match. Great! But for the width, because there is an allowable range, we need to consult a width compatibility table. Some tire manufacturers will be more permissive while others are more conservative with their published tables. And there are often separate tables for road bikes versus MTB. But these tables won't vary too substantially in their recommendations. Here are two tables, one from Continental and another from WTB.

    Continental width compatibility table

    WTB width compatibility table

    Both tables indicate that for the 13 mm rim width column, the recommended tire widths are 18-27 mm (Continental) or 23-25 mm (WTB). Your preferred tire has an ETRTO width of 40 mm, which is way too far outside of the recommendations. So no, it doesn't look like this tire can be safely mounted on your existing rims.

    But what would happen if you tried it anyway? We can see from the table that a 40 mm tire should normally be mounted on a rim with widths 17-27 mm. So 13 mm would mean the tire beads will be squeezed closer together than designed. This means more of the tire's tread will be wrapped up on the sides rather than facing down at the road. This also reduces the contact patch where the tire meets the road.

    Finally, a wide tire on a narrow rim exerts more leverage that could pull the tire up and off the rim. This would happen if the bike is loaded sideways, such as leaning the bike to one side while riding straight, or when the rider leans further than the bike in a curve. The recommended values take these conditions into account, so exceeding the recommendations might still work day-to-day but fail during rarer conditions.

    My recommendation is to pursue a new set of rims that can support tire widths suitable for your new environment. As the tables show, 13 mm rims are very limiting, but 17 mm rims are very permissive. Indeed, a 17 mm rim would actually allow you to mount your preferred tires (ETRTO 40-622) and possibly your existing tires (ETRTO 25-622 ?) too, if you wanted to.

    I wish you good luck in your endeavors!

    8
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearEL
    Jump
    Guess what happened here
  • "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearLI
    litchralee
    4w ago 100%

    This reminds me of the time I happened to be at a warehouse where an industrial motor control panel was being decommissioned. In the center of the panel is a large breaker, which was dutifully opened (ie powered off) before work commenced. But bizarrely, someone in the past managed to tap power from the supply-side of the breaker for some sort of monitoring sensor inside the panel. So when that circuit was cut through, there was a loud bang and the overhead lights went out.

    No one was injured, although everyone was jumpy from the inadvertent light-and-sound spectacle. And a set of cutters gained a 12 AWG-sized (approx 4 mm^2) hole.

    I may have misremembered some details, but my takeaway as a non-electrician was to 1) never assume a breaker handle at face value, and 2) don't assume the prior person made sane choices.

    32
  • photo.walgreens.com

    Use the code on the Walgreens app and the website to claim the same offer twice! When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    5
    1
    photo.walgreens.com

    Use the code on the Walgreens app and the website to claim the same offer twice! When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    0
    0
    https://www.cvs.com/photo/create/builder?sku=CommerceProduct_7182&category=prints

    You must have exactly two 5x7 glossy prints in your cart for the code to apply. When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    4
    0
    "Initials" by "Florian Körner", licensed under "CC0 1.0". / Remix of the original. - Created with dicebear.comInitialsFlorian Körnerhttps://github.com/dicebear/dicebearMI
    Survey of ebikes, escooter injuries: injured ages skew higher, not lower
    jamanetwork.com

    > The median age of injured conventional bicycle riders was 30 (IQR, 13-53) years vs 39 (IQR, 25-55) years for e-bicyclists (P < .001). Scooter riders had a median age of 11 (IQR, 7-24) years at the time of injury vs 30 (IQR, 20-45) years for e-scooter riders (P < .001) (Table 1 and Figure 3). As a group, those injured from EV accidents were significantly older than those injured from conventional vehicles (age, 31 vs 27 years; P < .001) (eTable 1 in Supplement 1). > e-Bicycles have lowered barriers to cycling for older adults, a group at risk for physical inactivity.9,10 Biking has clear-cut physical and cognitive health benefits for older adults, so this extension of biking accessibility to older e-bicyclists should be considered a boon of the new technology.22,23 However, as injured e-bicycle riders are older than conventional bicyclists, the unique safety considerations for older cyclists should be a focus of ongoing study. There is a popular conception that ebikes are ridden recklessly on streets and sidewalks by youths, doing dangerous stunts, riding against traffic, not wearing helmets, and incurring serious injury to themselves and others as a result. This conception is often used to justify legislation to restrict or ban ebike use by minors. However, the data suggests quite the opposite, as it is older riders which are racking up injuries. The data does not support restrictions on ebikes, but rather their wholesale adoption, especially for audiences which are at risk of inactivity or disadvantaged by a lack of transportation options. [Ebikes are not at odds with conventional bicycles](https://www.calbike.org/why-you-should-support-e-bikes-even-if-you-dont-ride-one/). The California Bicycle Coalition [offers this succinct summary](https://www.mercurynews.com/2024/08/19/increase-in-e-bike-injuries-spurs-bay-area-cities-to-take-another-look-at-regulation/): > “We think this backlash against e-bikes is the wrong direction for what we want for safer ways for people biking and sharing the road,” said Jared Sanchez, the policy director for the California Bicycle Coalition. “We don’t believe that adding restrictions for people riding e-bikes is the solution.” They also have a page on how to fight against "bikelash", aka naysayers of bicycles and bikes: https://www.calbike.org/talking-back-to-bikelash/

    19
    13
    photo.walgreens.com

    Use the code on the Walgreens app and the website to claim the same offer twice! When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    4
    0
    foldupkayaks.com

    I have no prior kayaking experience except occasionally paddling one while camping with friends on still water. That's fun and all, but I'd like to get out on the water on my own, to some of the nearby lakes near me, maybe once a month during the sunny seasons. None of these would have anything remotely considered as "rapids". My main consideration is transporting a prospective kayak, as I greatly prefer biking rather than driving a car for distances within an hour of me, which includes two or three suitable bodies of water. While I have the capacity to store a conventional hard-shell kayak at home, I'm exploring a folding kayak, since this could go with me in a car for farther locations, on a bike for nearby waters, and even a bus. I feel the hassle of moving a 12 ft hard-shell kayak would discourage me from ever using it outright. This specific model won't ship until October, which might be a bit late in the season, but it's on sale for $300 out the door, or $273 because of a 10% email coupon for keeping it in my cart for an hour. I'm aware that this isn't anywhere comparable to conventional kayaks, certainly not in price, rough water handling, and maybe not even longevity. But at this particular juncture, and for that particular price point, I think I have a use-case that aligns well with a folding kayak, and if I do develop the itch for something even better, I can always upgrade later. I can accept that this might be a "kayak-shaped toy", but if it floats on water and moves, I would be happy to start with that. To that end, my questions for this community are whether there are other comparable folding kayaks I should look at, or reasons I should or shouldn't proceed with this purchase in the coming days. Any and all advice would be greatly appreciated! **Update**: I've ordered it and hope to see how it turns out when it arrives in October

    9
    1
    photo.walgreens.com

    Use the code on the Walgreens app and the website to claim the same offer twice! When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    3
    0

    cross-posted from: https://sh.itjust.works/post/22165919 > This entry of mine will not match the customary craftsmanship found in this community, but seeing as this was formerly a pile of miscellaneous, warped scrap 2x4 segments recovered from old pallets, I think I've made a reasonable show of things. > > This bench is for my homegym, designed to be stood upon, which is why there's a rubber mat inlaid on the surface, a leftover of the gym floor. My design criteria called for even the edge of the top surface to support weight, so the main "box" of the bench uses 2x4 segments mitered (badly) together at 45 degrees, held together with wood glue. > > I then routed the inner edge to support a 1/2" plywood sheet, which is screwed into the box. And then the rubber mat is glued down to the sheet, so there are no visible screws. > > Finally, the legs are also 2x4 segments, cut so the bench sits 43 cm (~17 inch) from the floor; this is only coincidentally similar to the IPF weightlifting bench standards. I used screws instead of glue, just in case the legs needed to be shortened later. > > All edges were rounded over with a 1/2" bit, as the bench is expected to be picked up and moved frequently. And everything stained in cherry and clear-coated. > > Some of the annoyances from using scrap included: > * Stripping old paint off. Awful chemicals, awful scrubbing, awful disposal. > * Sanding away twists along the 2x4 segments > * Filling nail holes or arranging them so they don't draw attention > * My lack of experience with clamping and gluing wood that's not dimensionally consistent > > ![wood bench beside a leg press](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F235cb904-d512-402e-b620-f6cbc45b187b.jpeg) > > If I were to do this again, I'd figure out a way to reduce the amount of routing needed for the inner edge, since I essentially removed 0.75 inch by 1.5 inch of material all around the edge. This took forever, and perhaps a CNC machine would have simplified things, in addition to squaring and planing the surfaces before mitering. > >

    104
    3

    This entry of mine will not match the customary craftsmanship found in this community, but seeing as this was formerly a pile of miscellaneous, warped scrap 2x4 segments recovered from old pallets, I think I've made a reasonable show of things. This bench is for my homegym, designed to be stood upon, which is why there's a rubber mat inlaid on the surface, a leftover of the gym floor. My design criteria called for even the edge of the top surface to support weight, so the main "box" of the bench uses 2x4 segments mitered (badly) together at 45 degrees, held together with wood glue. I then routed the inner edge to support a 1/2" plywood sheet, which is screwed into the box. And then the rubber mat is glued down to the sheet, so there are no visible screws. Finally, the legs are also 2x4 segments, cut so the bench sits 43 cm (~17 inch) from the floor; this is only coincidentally similar to the IPF weightlifting bench standards. I used screws instead of glue, just in case the legs needed to be shortened later. All edges were rounded over with a 1/2" bit, as the bench is expected to be picked up and moved frequently. And everything stained in cherry and clear-coated. Some of the annoyances from using scrap included: * Stripping old paint off. Awful chemicals, awful scrubbing, awful disposal. * Sanding away twists along the 2x4 segments * Filling nail holes or arranging them so they don't draw attention * My lack of experience with clamping and gluing wood that's not dimensionally consistent ![wood bench beside a leg press](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F235cb904-d512-402e-b620-f6cbc45b187b.jpeg) If I were to do this again, I'd figure out a way to reduce the amount of routing needed for the inner edge, since I essentially removed 0.75 inch by 1.5 inch of material all around the edge. This took forever, and perhaps a CNC machine would have simplified things, in addition to squaring and planing the surfaces before mitering.

    77
    0
    https://www.cvs.com/photo/create/builder?sku=CommerceProduct_7182&category=prints

    When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    1
    0
    https://www.cvs.com/photo/create/builder?sku=CommerceProduct_7182&category=prints

    This is different than the [promo from two days ago](https://sh.itjust.works/post/20950773). When uploading photos using the desktop website, make sure to select Full Resolution in the Upload Preferences.

    7
    0

    cross-posted from: https://sh.itjust.works/post/20965205 > This is the story of how I turned a [15" Titan adjustable dumbbell](https://titan.fitness/products/loadable-15-in-olympic-dumbbell-handle-pair) to be 80 cm (31.5 inch) long. Why? Because I have [a space-constrained home gym but still wanted a leg press](https://sh.itjust.works/post/20320680), and so I had to remove its original barbell. > > In its place, I built a pair of wood mounts for a normal barbell to rest upon, covered in that earlier post. However, since this machine is wall-adjacent, such a barbell would have to fit inside the width of the leg press, so about 80 cm. But must also be wider than the spacing from outside-edge to outside-edge of the wood mounts, which is 60 cm. > > ![wooden mounts where a leg press barbell would be](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F30f0ce3c-6938-418a-8e1a-0c9e302ceebb.jpeg) > > Such a short barbell -- or long dumbbell -- does not readily exist commercially, with the narrowest one I've seen being 48 inch barbells, which are still too wide. So I decided to build my own, using my spare Titan dumbbell as the base. > > To start, the Titan dumbbells are excellent in this capacity, as the shaft diameter is 28 mm -- [not 32 mm as the website would indicate](https://titan.fitness/cdn/shop/files/430364_02.jpg) -- which is a common diameter, if I am to cut short a cheap barbell to replace this dumbbell's shaft. > > In keeping with my [preexisting frugality](https://sh.itjust.works/post/20133956), I purchased [a cheap 1-inch barbell](https://www.amazon.com/dp/B09FFQR9C8), hoping that it adopts the Olympic 28 mm shaft diameter, and not the 29 mm deadlift bar shaft diameter, as the Titan collars have small clearances. Matching neither, I find that this bar is closer to 23 mm, which although will fit into the existing collars, poses its own issues. > > Nevertheless, this 7 ft barbell can conveniently be cut in half to yield two 42 inch segments. And then the included bar stops can be loped off, and then the length further refined to 77 cm, thus hiding the marks from the bar stop within the Titan collars, and also centering the (meh) knurling from the cheap bar. > > But perhaps a picture will be more explanatory. Here, the original collar is dismantled at the top, showing the original shaft with a groove cut into it, about 1/4-inch from the end. Into that groove would fit two half-rings with an inner diameter of 20.4 mm and an outer diameter of 40 mm. In fact, all the parts inside the collar use 40 mm outer diameter, except the spacer cylinder, which is smaller at 37 mm. All of these parts are held captive within the collar using the C-ring and the geometry of the collar itself. > > ![](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F57f58ccd-ea27-4c41-a3d2-2f92f475da56.jpeg) > > To deal with the difference between the collar expecting 28 mm, and the cheap bar's 23 cm, I designed an ABS 3d printed part in [FreeCAD](https://www.freecad.org/) to act as a bushing, upon which the original Titan brass bushing will ride upon. This ABS bushing is held captive by way of its center bulge, which fits within the dead space inside the collar. > > ![](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F29cd9014-2151-4f70-baed-705c37f17e3c.jpeg) > > As for how I cut the groove into the end of the new shaft, I still don't own a lathe. So the next best is to mount an angle grinder onto a "cross slide vise" taken from a drill press, with the shaft secured in a wooden jig to only allow axial rotation manually. The vise allows precision control for the cutting wheel's depth, with me pausing frequently to measure how close the groove is to the desired 20.4 mm inner diameter. This is.... not a quick nor precise process. But it definitely works. > > ![](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F916ab05d-b76c-4c5e-93fb-d5ad5e64aa67.jpeg) > > After reassembling both collars onto the new shaft and lubricating with white lithium, the final result is a long dumbbell (or short barbell) with Titan's 3.5 inch collars on the end, with 63 cm of shaft exposed and 80 cm from end to end. The ABS bushing is remarkably smooth against the brass bushing, after some sanding with 180 grit. The whole dumbbell weights 5.48 kg empty. > > ![](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F1eefd286-80e5-4d92-ae24-30e5080f2d96.jpeg) > > Here is the comparison with the stock Titan dumbbell. It's pretty amazing how the knurling conveniently lined up. It fits well onto the wood mounts of the leg press. > > ![Don't ever talk to me or my son ever again](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2Fb9f862be-157f-4c2b-a692-1b875127390b.jpeg) > ![](https://lemm.ee/api/v3/image_proxy?url=https%3A%2F%2Fsh.itjust.works%2Fpictrs%2Fimage%2F4beca63d-17cf-4268-b1b6-b5720c5ca7ad.jpeg) > > But why would I do all this just to add a weirdly long 3.5-inch collar dumbbell to a leg press, when it already can accept weights underneath the carriage? I will answer that in [a follow-up post](https://sh.itjust.works/post/21422161).

    42
    4