HPsquared 11 hours ago

There are a couple of extra factors to consider:

1. Does the part give clear "warning" that failure is imminent (e.g. sound, feel, appearance), or will it just fail suddenly? (This characteristic is often a key design feature of safety-critical equipment)

2. When the part fails (note, different failure modes should be considered separately), what is the range of outcomes? (E.g. drive failure is dangerous if you're crossing the street, not so dangerous at other times; bell failure could occur at the worst possible time, etc). Then on the other hand we have structural failure of the frame and handlebars etc which are almost guaranteed injury.

So if you are riding a bike with lightweight racing components that aren't designed with a "leak-before-break" philosophy, riding in mountainous terrain in a crowded peloton, then yes - pretty much any small deviation from normal could cause a massive pileup. On the other hand, a leisurely commmuter ride on a quiet path has much more tolerance for component failure.

  • tetraodonpuffer 11 hours ago

    it still depends what component it is, when I was a teenager I was riding a bike with rim brakes, the bolt holding the front rim brake to the frame broke all of a sudden during very light braking, the caliper rotated and got caught between the spokes and the front fork leading to the front wheel immediately stopping leading to me performing a superman dismount (since then I've ALWAYS worn bike gloves when riding). There had been no signs at all that the bolt was about to fail.

    In my experience (many years of riding, quite a few years of bike commuting full time included) most mechanicals on the front wheel mean a fall/crash, but everything else just leads to having to walk home if you don't have the right tools (carrying a couple spare chain links in addition to the typical flat repair stuff and a full set of hex keys lowers the chance you'll have to do so).

  • jappgar 7 hours ago

    Sudden catastrophic failure is of the reason carbon fiber mountain bikes are a dangerous development.

    Modern mountain bikes live in this weird consumer space. They are designed to stand up to incredible stresses while remaining light and agile. But they're increasingly purchased by people who don't really need high performance gear, they just like the idea of owning "the best" stuff.

    I imagine the same thing is true with pickup trucks. What once was utilitarian becomes a vanity object. Now it's harder for people who genuinely need the performance.

    • cenamus 7 hours ago

      And "the best" for those people is definitely not a mountain bike. But I'm sure it's the same factor as for SUVs, it looks cool and is big and scary. Pretty much everyone would be better off with a citybike and a decent geartrain + wheels

  • eitally 9 hours ago

    I think this depends a lot on the rider and their level of experience (just like it does with drivers). Modern ICE cars are so quiet (to the point that many cabins feature ANC to help mask engine noise) that you'd never be able to hear a whining belt or misfiring spark plugs, and perhaps not even squeaking brake pads. Bikes are similar but the rider is much more directly connected; even so, many riders are pretty oblivious to how they work or how to fix problems.

    • alphabettsy 6 hours ago

      I don’t think automotive anc is typically that sophisticated. It plays certain fixed frequencies based on speed, load, etc. You can still hear mechanical issues especially higher frequencies which aren’t masked at all and a misfire typically causes a noticeable roughness, but that would be detected by the computer is most instances.

  • kqr 10 hours ago

    > drive failure is dangerous if you're crossing the street, not so dangerous at other times

    As TFA states, it depends on how much you're relying on it to keep balanced.

pentamassiv 11 hours ago

Modern bikes allow novel attacks too. I wrote a blog post about how to downgrade the firmware of a Shimano Di2 groupset and doing a replay attack to shift someone elses bike.

https://grell.dev/blog/di2_downgrade https://grell.dev/blog/di2_attack

  • bikesnobikes 8 hours ago

    > https://grell.dev/blog/di2_attack

    > must be within a couple of meters of the bike

    The range of radio transmitters/transceivers can be increased, and accidental transmissions from various things could affect it.

    Choosing to allow any kind of remote control over a manned vehicle is a risk. There can be benefits, but winning a race may not be worth giving up your life.

    Similarly, I don’t want IoT devices and won’t connect them when I have to buy them. I’d prefer to keep my thermostat and appliances safe, and a neighbor can turn them off if I forget.

  • tetraodonpuffer 11 hours ago

    this is why if I was a sprinter a the TDF I'd 100% be on a mechanical groupset (assuming the sponsors allowed me to) a missed shift on a sprint means losing 100%

exabrial 9 hours ago

One thing to know about torque wrenches: it’s actually more important that they are consistent rather than having absolute accuracy. (for the most part) why is this? If you have four bolts tightening down a handlebar into a stem, using a torque wrench correctly ensures consistent clamping load and avoids creating a stress point.

Whether those four bolts are at 8.86nm or 7nm is not usually a big deal. This is strictly speaking about bicycles, however, not aircraft or rockets :) there are a few bolts where an absolute clamp load on a single fastener is important: controls on a carbon bar. For my experience, though I have seen some bike shop mechanics reef on these (8-12nm) without consequence, even though the manual clearly states 4nm. I would do exactly what the manufacturer says here.

xg15 8 hours ago

OP is probably not wrong, but also the article sounds a bit like written in the Final Destination universe.

  • haiku2077 6 hours ago

    I've been on two wheels long enough and have enough titanium in my body to know this shit really does happen

    • xg15 6 hours ago

      I can imagine handlebars breaking or a wheel suddenly coming loose or a mechanical gearshift just ripping off because you were a dumb teenager and didn't realize that switching while going uphill is a bad idea. (had the pleasure of the last two)

      But seatposts "apple-coring" riders through the saddle? What?

      Or the chain springing out of the gear just while you're climbing uphill on the wrong side of a road next to busy traffic, and the sudden jolt throwing you off balance and making you sway into the traffic?

      • haiku2077 6 hours ago

        I have lost a chain twice on motorcycles! Can definitely be sketchy if you don't react immediately.

        And the seatpost thing is one I've heard about - IIRC Peloton had to recall several million stationary bikes because of a similar failure.

        • xg15 6 hours ago

          Ouch... wouldn't have thought, but thanks for telling.

donatj 10 hours ago

This undervalues how much it depends on context, how and where you ride. Cycling is varied.

My casual rides to the shop on my beach cruiser in my sleepy little town? Both my wheels could come off and I'd probably be fine. I'm rarely hitting 10mph.

Downhill mountain biking? Yeah, basically everything is important.

Aside, I was expecting an article comparing good software to a bicycle. Every part of good software being important and well maintained.

  • thorin 10 hours ago

    Downhill mountain bikers basically expect their bike to be destroyed and train to bail and are dressed for impact. Road cyclists wear no protection other than some thin skimpy lycra and don't fall often but when they do it can be catastrophic.

  • Scarblac 10 hours ago

    Yes, this article seems to be about racing bikes.

    • kqr 10 hours ago

      Or commuting in locations without good infrastructure (which is almost everywhere). That exposes you to both velocities and traffic that can be seriously harmful.

WillAdams 11 hours ago

The basics are as simple as ABC (Air, Brakes, Crank/Chain/Cassette) and on some newer bikes, a Q (Quick releases):

https://bikenewportri.org/abc-safetycheck/

There is also a certain matter of training --- badly bent a frame when I was young because I wasn't taught how to deal with a brake failure (rainy day and steel rims) --- the answer of course is to put one's foot up on the front wheel:

https://bicycles.stackexchange.com/a/7287/7344

Of course, the biggest danger could also be addressed by training --- as a part of getting a driver's license, drivers should be taught the "Dutch reach":

https://www.theaa.com/driving-advice/safety/dutch-reach?msoc...

and riding a bicycle a mile or two in practice and a use of/review of hand signals should be a part of the road test.

andrewaylett 9 hours ago

Can confirm: my chain snapped cycling along Princes Street, and I couldn't wear trousers for about ten years. Turns out that sliding down the road isn't very good for the skin on your knee.

Most frustratingly: I'd already ordered a replacement, it just hadn't arrived yet.

  • yladiz 6 hours ago

    Do you have an idea what happened? Was it a "factory" failure that you couldn't have seen coming, or was it due to something like the chain being very old and worn out?

  • spooky_deep 3 hours ago

    The tram track situation on princes street was outrageous.

Dazzler5648 8 hours ago

This piece seems ignorant of regular people's realities. Many people cannot afford the luxuries of this elusive fancy "safe" bike with well-engineered parts, kept on a professional maintenance schedule. I suspect this really isn't an issue for most HN readers, and the fear-mongering just heats simmering angst. Remember a cure for angst is to 1) ride your bike and 2) donate time and resources your local bike repair cooperative or homeless shelter.

Author seems to forget the most important part of the machinery is the rider. What a glorious machine! He also seems to forget that millions of people in the world are riding bikes, motorbikes, and cars scrapped together from whatever they can afford or find. Forced to accept the risk, they usually get where they're going. I wonder does the author check out the maintenance of every Uber he hops into? "Let me see your torque wrench!?"

I've built and maintained all my own bikes since around 2005 with no training. It doesn't take a genius or a torque wrench to keep a bike rolling. I recently dropped my standards quite a bit on two bikes: One where I took a decent 2021 FS trail MTB I'd maybe ridden ten times on a black diamond downhill singletrack and another where I took a 1998 HT MTB with seized shifters, no grips, crusty, barely-functioning brakes and a sun-baked Hellraiser-looking rear tire held together only by a thin sheet of kevlar(?) around the streets of Portland, Oregon for three weeks wearing no helmet. I know, I'm a monster.

As an aside, I ride a 2005 Yamaha YZ250 (dirt motorcycle) my ex maintains... that feels sorta... dangerous.

saidinesh5 11 hours ago

One of the surprising failure i didn't anticipate with bicycles was how little contact the tires made with the road..

Even when the brakes fully work, the tires don't provide enough traction to stop quickly ...

Ever since that last big crash I am way more cautious about all the ways my bicycle can fail me while riding.. the one good thing is there aren't that many parts to worry about with bicycles

  • kqr 10 hours ago

    I'm sure you know this but a lot of people don't: if you want to stop quickly, use the front brake while adjusting your weight backward. The rear wheel can skid along a good distance, but if you apply the front brake to the point of wheelie liftofff but no further, that's as fast as you'll stop.

    Aside from just laying down and scraping yourself against the rode, which might still be preferable depending on the alternative!

    (Gravel or other slippery surface where the front wheel would just skid? You're toast. Ride slowly instead.)

    • analog31 10 hours ago

      Moreover, a lot of casual cyclists don't use the front brake at all -- evidenced by the condition of the front and rear break pads on bikes I've worked on. I think that effective use of dual braking is vital to safe riding.

      I advise beginners (yes there are a lot of them) to practice making panic stops in a safe place such as an empty parking lot.

      • Fricken 8 hours ago

        I've been riding a fixed gear in traffic daiily for 14 years and it has never actually been necessary to panic stop in that time. I have a front rim brake and only use it on the big hill.

        As a hypothetical one would think it would be necessary to slam on the brakes more often, but the situation has never come up.

        • mariusor 7 hours ago

          I think the more you cycle the more managing speed becomes a function of predicting traffic around you than needing to react to unexpected things. Rarely an obstacle in your path is truly "unexpected" if you're able to understand how other participants in traffic will move.

          • analog31 7 hours ago

            It's come up often enough for me, in 55 years of riding.

            Experience does make a difference, but I haven't yet seen the risk of an unexpected stop drop to zero. And I think learning to control the bike is still valuable for a beginner, so they can survive to the point of developing their street smarts. A panic stop teaches you how to control the bike.

            The recent e-bike boom has been a chance to observe a lot of beginners learning to ride. One habit I've seen on the paths is being "afraid to stop," resulting in minor collisions within groups of cyclists, and cars making panic stops when the bike paths cross roads. These are the people to whom I suggest learning how to use the brakes.

      • mariusor 9 hours ago

        A panic stop while turning is a sure way to get a face full of asphalt even for seasoned riders. Don't try that please.

        • analog31 8 hours ago

          Edited per your suggestion.

    • saidinesh5 6 hours ago

      > Gravel or other slippery surface where the front wheel would just skid? You're toast. Ride slowly instead

      Yup! Can't stress this enough. The last big crash was literally slippery road and a speed bump. The bicycle did a full 180. I'd have probably been better off if i just didn't brake at all... Didn't notice the speed bump in the darkness and when i suddenly did The front brake was on, the bike hit the speed bump after skidding.

    • 7952 9 hours ago

      And tense your arms muscles and hand grip when you brake. A lot of over the handle bar accidents are due to people not being ready to absorb the force of braking.

      Also, on uneven ground you can apply a little brake to get a sense of the surface. Feel how the bike responds and moderate accordingly.

mrob 11 hours ago

I think the chain slipping off the cogs is one of the most concerning failure modes because it tends to happen only under heavy acceleration, e.g. to dodge traffic at a busy intersection. Everything can seem fine and then you're stranded without power exactly where you need it most. It's worth regularly checking for wear and correct adjustment.

decasia 8 hours ago

I was trying to reinstall my rear wheel the other day after removing a bike trailer. I apparently didn't tighten it down enough and the wheel came out of the brackets as soon as I started to ride, causing an instant crash and a lot of bruises.

Things like that make me feel apprehensive about trying to learn more bike maintenance stuff myself. It's almost inevitable to have to patch flat tires though so you're always going to be reinstalling the wheel yourself, but I don't touch the brakes even if it seems like an easy fix.

  • ddtaylor 8 hours ago

    Regarding the tires. I don't know if it messes with how you ride or anything, but we have the tire slime in all of our tires and we keep a portable Ryobi electric bike pump with us when we go on trails.

    Brakes suck. For maintenance I actually enjoy the regular brakes instead of the hydraulic ones. You have to realistically change your break pads every month or two and it's difficult to do with the hydraulic ones by comparison.

    • mauvehaus 5 hours ago

      What are you doing that you're changing brake pads every couple months?

      For non-cyclists: brake pads have a minimum thickness, and usually a wear line molded in (less common on disc brakes). If you've got enough pad material and it isn't glazed or contaminated, it isn't time to change them yet. They can last years. I've got maybe 6,000 miles on the pads on my road bike, and they're fine.

      The only normal case for needing to change pads every couple months that I've run across is people riding lift-service downhill. In which case, buy a set of digital calipers and check your rotors regularly, because they have a minimum thickness too.

      For reference: I am a bike mechanic, though not a paid one at the moment.

  • ddtaylor 8 hours ago

    This is my biggest fear when working on my bike. I tighten those with that fear in the back of my head constantly. I have to be careful not to over-tighten them because of this.

zkmon 8 hours ago

I see each part playing a functionality role, instead of safety-related role. A broken functionality might cause a safety issue. but it is still a functionality issue. A rider could fall off when a pedal is broken. That's just an undesirable consequence of broken functionality. A broken functionality always means things not working as expected, and naturally causing unexpected results. Most unexpected results can be safety issues, unless it is a win of a lottery.

dbrowne 8 hours ago

1) avoid nockoffs of seat posts, stems and handlebars. Well known 2) A worn front chain ring won't negatively impact a rider. 3) it is a bicycle, not a helicopter. 4) Fear mongering is unnecessary 5) A torque wrench needs to be consistent. so long as it is within 10% you are fine 6) sounds like a bike shop owner trying to drum up business.

scotty79 9 hours ago

I definitely had some failures that didn't really influence safety but were serious enough. I lost one of the pedals during a hike and still came back home on this bike. I guess it depends on what you do.

amelius 8 hours ago

Speaking of which. Last week I parked my bicycle against a car. The owner got angry at me, which I don't understand, people park their bicycle against my bicycle all the time. And by doing that, it is far more likely that safety critical parts are damaged.

  • do_not_redeem 8 hours ago

    Does your bike not have a kickstand?

    • amelius 8 hours ago

      Yes, but the slightest amount of wind will make it fall and this is certainly not unique to my bicycle. It is better to leave a bike in a more stable position.

      • rags2riches 8 hours ago

        Turn your handlebar all the way to the right side (assuming the stand is on the left) and it will be much more stable.

      • do_not_redeem 7 hours ago

        Just because you bought a wrongly-sized kickstand for your bike doesn't give you the right to damage people's cars.

        • amelius 7 hours ago

          The kickstand is an integrated part on most bicycles, and yes they are often undersized. However, like I said, people think it is normal to park their bicycles against mine, so why should it be different with other vehicles like cars?

          • do_not_redeem 7 hours ago

            Because a car isn't a bike.

            Do you think people should treat cars and bikes 100% equivalently (including such things as whether you can drive them in the bike lane), or would you agree society should treat the two differently?

            • amelius 7 hours ago

              Depends on the circumstances. When it comes to surface scratches caused by the parking of other vehicles they can be treated equally.

              PS: your argument is a bit silly. Analogy: all humans are equal; except that does not mean that we should treat all people the same way in all circumstances.

              • do_not_redeem 6 hours ago

                > When it comes to surface scratches caused by the parking of other vehicles they can be treated equally

                So you're saying if a stranger damages your bike, that gives you the right to pay it forward and damage some unrelated stranger's car?