Aside: if anyone's trying to talk someone they care about out of purchasing something like this, I suggest tricking them into getting a skateboard first. I think that would ground most people in reality. Fuck around enough at low speed in less-than-lethal environments, you'll get onto a first-name basis with Newtonian Physics, and it'll clarify, on a viscerally intuitive level, what these types of machines are really about.
The first thought that comes to my mind looking at this device is "these are failure-is-not-an-option situations". There's many ways to fall off a skateboard without dying, and to me it's viscerally obvious, absolutely none of them will ever apply here. You can't recover onto your feet, because these lithium-battery things are like 300% faster than your top sprinting speed. You can't fall onto your arms either, because your inertial speed is faster than your autonomous reflexes. (You learn all about your autonomous reflexes). It's just your face, and skull. This is the first thought that comes to mind: there's no way to bail, 0% chance. It's just completely not-an-option to fail on such a device at cruising speed. And I'm grounded enough to realize, I'm not a person who never fails physical feats. That's not what a human is.
I built my own electric longboard with enough power to throttle my hefty frame up to 25mph. It was perfectly tuned for me. I swapped out so many parts to get it just right. In the first hours of riding it, I took a fall that had me out of commission for a week. I was going 10mph!
Once I got the hang of things, I used the board to commute daily for a few months - putting ~ 8 miles on it daily. To this day, I consider daily rides on this board to be the single highest life threatening risk I have taken to date. I realize that now.
For anyone looking to use a board or one wheel or e-unicycle, please reconsider.
All it takes is one missed sign, one pothole, one inattentive driver, one loose bushing, one nail on the road, one patch of oil. You get the idea. The number and variety of risks and significance of the damage they could do should be enough to avoid.
With electric boards (not the one wheel) you need to constantly manage your center of gravity. This means if you want to break because of a hazard, you MUST shift your center of mass to lean in the direction of travel while slowing down. It takes some time to naturally manage throttle/brake in unison with your center of mass. After 3 months of daily rides, it still required intentional planning. Just let that sink in... All it takes is one "oh shit" moment where you miss the transfer of center of mass. You face plant and possibly slide directly under the path of the hazard you braked for.
If you still want to, get kevlar gear like motorcyclists use. Many have shoulder, elbow and back pad inserts. ALWAYS be padded and helmeted!
I rode an e-unicycle (EUC) for a few years as my main mode of transport. It was super fun, and after my first year I was really quite good at it, good enough to even dodge a few cars on instinct: my response was entirely unplanned, a reflex—a sharp turn, rather than an attempt to slow down, that I was shocked my body performed in retrospect. (Turns rely on center-of-mass and rubber friction, rather than motor acceleration or deceleration, which are limited.)
I loved riding that thing, it felt like flying. It was addictive. I rode it like wings, my instincts were so good it felt like I was one with it—it no longer required any intentional planning. Sure, I had my share of spills, but learned from each one where I'd messed up and how to become exceptionally careful, and was fortunate that I recovered from each in a few days.
I say all this because, like you, I now realize it was the single most life-threatening risk I've ever taken in my life. These things you write are 100% true:
> All it takes is one missed sign, one pothole, one inattentive driver, one loose bushing, one nail on the road, one patch of oil. You get the idea. The number and variety of risks and significance of the damage they could do should be enough to avoid.
> All it takes is one "oh shit" moment where you miss the transfer of center of mass. You face plant and possibly slide directly under the path of the hazard you braked for.
You are extremely exposed, and trusting your life to firmware developers.
99.99% of the time it is the unbelievable feeling of flying, slicing through the wind.
0.01% of the time it is slamming your body into rough pavement at 20mph, like diving face-first off a two-story building, no warning. No way to see it coming.
One day I decided to ride a cheap, narrow, narrow-wheeled skateboard down a fairly steep access road that led to a beach parking lot where I grew up.
At some point during the descent, the board started to shimmy violently, forcing me to jump off... but I was already going faster than I could run. But run I did, and my feet and legs literally fell behind my torso... upon which I fell and skidded down the asphalt, shirtless. I did manage to keep my chin up and off the pavement as I slid, however.
It was night-time and we were at the beach with some relatives. I gritted my way through playing in waves and showing my relatives around. Nobody noticed anything. When we got home and I walked into the light, my mom gawked at the shredded skin on my chest and, being a woman of considerable decorum, did NOT shout "WTF!!!" But that was definitely the nature of the response.
I’m sat here with a bunch of metal in my shoulder and a brain full of analgesia after coming off my mountain bike. I crashed at about a tenth of the speed I’d normally be going.
My helmet was trashed and definitely saved my life. I’m wondering whether extra padding would have saved me from weeks of pain, a surgery and months of immobilisation followed by months of rehab.
The thought of blasting down the road on a One wheel in T-shirt and jeans gives me chills now.
I mean bikes are soo much better than one-wheels and boards... the way you can "just" use tha brakes more or less freely on a bike without worrying about getting your CoG right before you do.. priceless.
But yes, of course people get hurt on bikes, too. But I believe you can be an order of magnitude safer at least.
Couldn’t say if that was a power loss issue or the wheel just got too deep in the mud, but doesn’t look fun especially if you imagine that fall on to concrete.
He’s probably going about 1/4 of this things top speed too.
I’ve had this same thing happen on a electric skateboard at about this speed but on asphalt. Shoulder dislocated, elbow broke, wrist sprain so severe I had to relearn how to use my hand. And I was a skateboarder my whole life leading up to that so I knew how to take a fall.
I still use electric bike and fat tire scooter/bike. But the high speed even on that feels sketchy. All it takes is a little gravel or something and you’ll lose your front wheel and eat it hard. That actually happened to a friend growing up, we were flying down a steep hill (ok maybe 20mph) on our BMX bikes. He hit gravel and the front wheel slid out. He had to have his upper lip stitched back on.
And you'll notice that he successfully plants his left foot, but momentum just carries him ahead and into the fall and roll. And this is a best case scenario.
"The deaths came as a result of head trauma, with at least three of the accidents happening with the rider in a helmet."
Where are you getting that quote? The article seems to contradict that:
"Alongside the US Consumer Product Safety Commission (CPSC), the company now seeks to remedy the products after four known death cases — three without a helmet — between 2019 and 2021."
I see someone riding one of these around my neighborhood in what is essentially full motorcycle gear:
- full helmet with closed visor
- armored jacket with elbow pads
- knee pads
- all high vis
Still doesn’t look like it’s enough while they cross a street in front of turning cars.
All various motorcycle helmet standards. ECE is the EU standard, DOT is the US Department of Transportation standard, FIM is another, stricter EU standard (Functional Independence Measure), and Snell is not an acronym but is an independent safety testing organization.
Also when I was buying my motorcycle gear (8 years ago) the general conses I recall is that ECE ~= DOT. Not sure what OP means regarding DOT certification.
- is nearly 50 years old without meaningful changes to reflect half a century of head injury and brain injury research
- has significantly lower standards for how much force can be transmitted through the helmet to your skull - well within values that commonly cause skull fracture
- does not have any brain injury criteria for rotational trauma
- does not have any independent random testing, and limited independent random test studies have found 50% of labeled helmets don't meet the standard
The last point is especially frightening! ECE has fixed all of these issues. Fortnine's videos on this (and the problems with Snell 2020R/2020D) are a great place to learn more.
He hopefully wasn't expecting to stop himself like that, that looks painful, it's asking for a sprain! But what a nice roll, does the fellow practice judo?
During my brief stint with longboarding, I found that tumbling (as taught in gymnastics, martial arts, parkour, etc) is quite useful for a high speed unplanned dismount. That would be applicable here too. However, my stint with longboarding was brief because less than 100% of crashes led to a successful tumble.
If you are riding with good posture and awareness it you can run out and roll from a one-wheel.
You might not be able fully "run it out" given the speed, but every step you take when bailing is a good thing and rolling out after you take a few steps will help as well.
At the end of the day, it's obviously going to be more dangerous than a bike or a scooter, though. My issues with future motion is more to do with their extremely poor response to design flaws, though.
I think that riding at more reasonable speeds and riding with focus and awareness is still reasonable, but the faults we've seen add hidden risks that are difficult to address as a rider.
That might be true unless your knee buckles or foot sticks blowing out your knee, acl, mcl, cartilidge which happened to me at 9mph. Luckily I only sprained the MCL for the 3rd time.
Wait what? I mean I agree about being able to fractionally run it out (I spilled at full speed when i first rode one of these and came out mostly fine because of a decade of skating) but there's no way that these are more dangerous than bikes or scooters. There are way more ways to get tangled/impaled (not usually literally, but more ways to have crash force concentrated in a smaller area) when crashing a bike/scooter.
Scooter I can kind of see the argument for. But bike not so much. Assuming we’re talking peddle bikes here, then they’re naturally self stabilising, and capable of far heavier breaking than a One Wheel is.
A One Wheel requires quite a lot of active balance from the user, a bike requires some balance, but hard cornering on a bike, or slamming the breaks on hard don’t generally result in unplanned dismounts, even with amateur bike riders. A One Wheel on the other hand, even experienced riders will still end up doing unplanned dismounts when performing rapid unexpected manoeuvres (such when avoiding another vehicle or pothole).
It’s only anecdata, but I’ve personally never had a serious unplanned dismount on a bike (after thousands of hours), and includes while mountain biking. I’ve have had a couple of nasty unplanned dismounts on a One Wheel just riding around a park. I suspect broader stats (assuming anyone’s even collected them) would probably find that my experiences of each mode of transport is pretty representative.
Been a long time and the link is lost but I saw a California DOT study that had Italian style scooters as dangerous as bicycles. It's at odds with what motorcyclists think. Also at odds the risk from motorcycles goes up sharply with displacement.
My personal experience was all dismounts from bicycles lead to bruises if that. And friends crashing at high speed tend to end up with hand and wrist injuries. Flip side I have three friends that needed knee surgery after stand up scooter accidents.
So I agree the typical dismount is really important.
That's a fair point, in terms of the odds of an incident being bad I would say scooters and bikes are more dangerous, but the odds of an incident happening at all on the onewheel is much more likely .
I think I would agree that you can probably have a much worse incident on bike vs a One Wheel. A bike allows you reach effectively unlimited speeds (provided you can find a big enough hill and tail wind), which brings with it uncapped risk.
But I think for most average bike riders, people who just ride a bike to get from A to B, rather than for sport (more speed always means more risk, at certain point I agree a bike becomes inherently more dangerous just due to the higher speeds). The odds of them having a bad incident on a bike is much lower than on a One Wheel. It’s quite hard to have an incident on a bike that results in a guaranteed head injury (please wear a helmet, it only takes a single bad head injury to ruin your life), whereas it’s quite hard to avoid a head injury from a One Wheel incident. Most bike related incidents (where someone isn’t just riding into a stationary object, in which case I don’t think the mode of transport matters much) result in the bikes wheel slipping out from under you, the consequence is moderately slowed, but quite painful fall sideways. The time it takes the bike to fall out from under you gives you a bit of time to prepare for the impact. All this assumes reasonable low speeds (not much faster than a run), due to non-sport based riding.
On a One Wheel or similar, dismounts tend to result in full bodied face plants. If you’re not able to come of the device, and catch yourself by running, then you tend to go face first to the pavement, and there’s nothing slowing you down. No bike frame or similar sliding across the ground and buying you time, just a whole load of empty air between your head and the ground.
If the rider is actively balancing then it doesn’t need to immediately nosedive. In reality that’s the usual effect, but keeping a low center of gravity and trying to keep it balanced go a long way toward a smoother slide/roll instead of a faceplant.
The rider leans forward to accelerate the OneWheel, so they are not "actively balancing" - the OneWheel self-balances "against" their lean. Until the motor gives out, that is.
Simply carving , which is how you turn, requires some balancing by the rider. Going fast over anything but ideal terrain also requires active balancing. If you ride one in any capacity beyond a few mph in a parking lot, you’ll feel it in your legs.
It’s very rare that bicycle is going to mechanically fail and send you flying.
Short of the time I was hit by a car, I’ve never had a bicycling emergency — road or mountain — that I wasn’t able to walk away from through some combination of hoping obstacles and/or putting the bike down in a controlled side-skid.
I've been an active skateboarder, snowboarder, and surfer for 25 years, and have ridden a One Wheel XR for about three years.
All are different in terms of most of the skills needed to do any of them.
The One Wheel is much more like a snowboarding in soft powder than it is like skateboarding, but even then, it's not quite the same. There's a sort of softish center pivot feeling, where on a snowboard it depends on where your edges are.
Skill wise, you don't need any to make the One Wheel do what's advertised. You do need skill to ride it confidently, but you gain those skills as you use it.
I've had one very bad fall on the One Wheel, and it was bad. It slide out while going fast down a steep slippery/sandy hill, and then nosedived, which sent me cart wheeling, then whipped my heel into the ground, shattering it into 23 pieces. I was in bed for 6 months, and didn't walk without help for 12.
I actually think my other boarding skills made the injury worse. I reacted as if the board was a skateboard, where a sideways slide is something I'm super comfortable with and do on purpose. That reaction was to lean deep, counter to the forces of the slide. The big fat gripping tire of the One Wheel bit in, then acted as a fulcrum with my body as the lever, and I just went sailing.
The advice from the GP to have One Wheel-curious people try a skateboard first is indeed good advice. It won't teach you how to ride a One Wheel, but it will teach you how hard the ground is.
Another good option for new riders is to learn to use a balance board first (like a Vew-Do). At the very least, step on the Onewheel while it’s powered off, slowly raise it to level and hold, then alternate slowly setting down each end and returning to level. If you can do that, you can recover from some situations that would otherwise result in a nosedive.
And another important one: braking. Something that has wheels and can move from inertia will need some mechanism to brake, and to emergency brake, especially on inclined / declined paths.
Here in Barcelona these things are super common. The riders seem to be pretty adept. The problem is more that they don't care about pedestrians, they zoom around while on their phones on the pavement where they're not allowed and zip around pedestrians way too fast.
I don't care if they kill themselves but they're risking other people's safety more.
I know a few people that bought these to commute around town. I always thought they were bat's hit crazy and did try, unsuccessfully, to talk the out of it.
I skateboard when I was younger and generally feel comfortable enough on any board where I can stand sideways. No way in hell I wanted to try these though, the top speed alone masks me way too nervous even with experience skateboarding, surfing, and wake boarding.
I have and ride a onewheel but never skateboarded. It really is a different balance; one-wheeling hasn't helped me a bit for skateboarding skills either.
My take on the safety bit is I would never ride the one-wheel at the top speed the device supports, and would never ride without a helmet or on a road with traffic. It can and will dump you. I've had the battery-out dump (when I knowingly experimented after its low power warnings). Basically if you go faster than you can run out/step and roll out from you're inviting yourself trouble.
Heck, just try skiing or snow boarding. I could never get over my fear of Newtonian motion, even with soft powder to make falling less dangerous, there were always just too many trees around.
Roller blades and ice skating are similar before you learn braking. I used to get Aron d on my rollerblades a lot, in a time before helmets were more common.
Both are far more forgiving than skateboarding, even given the speeds you're sometimes wiping out at.
You just sort of bounce down the slope, and it hardly even scuffs up your snow gear.
Wipe out at a quick on a skateboard - the pavement has no give, and you're not all bundled up because it's summer. You're getting road rash, minimum, maybe some more serious damage to bones, head, etc.
Rollerblades, not quite as bad. They aren't constantly trying to run away from you. Similar failure mode though.
Ride in the middle of the run to avoid the trees! Falling on hard pack is an excellent way to jolt yourself awake ;) In any event, carving at high speed keeps your body pretty close to the snow.
Was high speed carving a couple of years ago. Blew a turn and rag dolled. Broke 2 vertebrae in my neck and two in my back. Fractured the back of my skull. Speed + impact can get intense.
Ouch! Personally I try to keep speeds to the 40s now. Worst thing I ever did was start using those run tracking apps which conveniently also give you your speed. Got in a competition with a friend on the other coast and was regularly hitting 55+ on runs that a wipe out could easily end in the trees. What stopped me was when a late teen girl did just that and died going at far slower speeds.
What I like about snowboarding is it feels fast, even when you're going not-that-fast (at least in my case). I once had a friend video me coming down the hill, and when I watched the video, I thought: wow, I thought I was going much faster than that!
> It's just completely not-an-option to fail on such a device at cruising speed.
I recently flew off a normal bicycle because someone spilled oil or something in the middle of a roundabout. The helmet has a large dent, broke my arm.
I'd need full motorcycle gear before I try a monowheel/Onewheel/etc.
Think how many times a toddler entertains the carpet with his face whilst learning to walk and run - years of training is involved in us walking normally.
You need similar training to learn these other devices which can operate VERY unexpectedly compared to normal balancing.
The gamut of human capability when crashing vehicles is SO MUCH larger than most people realize. The average bike commuter probably has a much higher chance of injury in a solo crash than someone who's skated for decades on a onewheel. When I see discussions of safety I rarely see "get good at crashing" brought up, but it's such an important skill.
When I ride my bike I'm always hopping up curbs at speed, doing quick whip skids/ted shreds etc, not just because it's fun, but because those are the skills you need to stay alive in abnormal situations. It's honestly kind of baffling to me that most people don't actively work on expanding their safety envelope.
You can get good at crashing, and at avoiding crashes, and when you do you can either do the same things safer, or do more fun things with the same level of safety. This is why Alex Honnold isn't dead (yet).
> When I ride my bike I'm always hopping up curbs at speed, doing quick whip skids/ted shreds etc, not just because it's fun, but because those are the skills you need to stay alive in abnormal situations.
I've cycled to work for 15 years, and I've never hopped up a kerb and I don't even know what a whip skid / ted shred is.
I used to commute through London by bike. Like the cliche I was I ended up riding a fixie (everything else either got stolen or broke).
I found through trial and error that riding aggressively was safest, not because it was inherently safer but because everyone would take note of the idiot hooning around too fast and take extra caution. Of course the failure mode here is when someone doesn’t notice you…
Years later I now commute by bike in Cornwall where the local population is ignorant of cyclists. I ride an electric cargo bike with my son on the back and I’m incredibly conservative.
There’s no real difference in incidence of accidents, but incidence of “near-miss” and severity of possible accident? Hands down riding conservatively with no hopping around is safer. Duh! ;)
> I've cycled to work for 15 years, and I've never hopped up a kerb and I don't even know what a whip skid / ted shred is.
My commuter e-bike weighs a solid 80lbs fully loaded. I'm not hopping curbs or doing "whip skids" on it. I basically ride it like a touring motorcycle.
I think your chances of ever encountering a truly abnormal situation on a bicycle (that you couldn’t get out of with knowledge of how to use your brakes) is not something that happens to most people even once in their lives.
I once took a bike safety class that included practicing "quick turn", "rock dodge", and rapid braking. (I guess the last is included in "how to use your brakes".)
I'd like for my skills at each of these to be better than they are today, and I ride my bike quite a bit.
I rode in London, a lot. Fast, too.
Couple of accidents, once slipped off a pedal it speed, ran over my foot, but stayed on (thanks, physics), once got too close too a rising curb and couldn't steer, hit a fence at speed, got deep cuts and lots off bruises, but bike took most off the damage.
Have had accidents since, usually from heavy breaking, with complication leading to launching over the front.
I cannot see how these boards could be safer, any dismount at equivalent speed would need considerable skill to not face plant, and any complications would just add energy too the impact.
That or you could simply quail too stop in time and hit something (like a car door opening, or a truck pulling out, or that kid/dog that ran in front of you)
I've only crashed once in Copenhagen, when a tourist turned left directly from the right side of the lane.
Oh, and once when I was so drunk I fell off 2 seconds after getting on the bike.
In London it's necessary to plan a quieter route, using roads most people don't even realise exist. It can't be as nice as the Netherlands, but it can be OK.
A toddler's tiny mass, along with a rubbery and flexible body, allow them this luxury. An adult's mass quickly runs afoul of the above mentioned physics-gut-check.
That greatly depends on the surfaces involved and the persons skills.
I’ve fallen off the back of a galloping horse before as an overweight 6+ foot guy and been fine, but that frequently causes severe injuries. I doubt a one wheel rider is dealing with significantly more energetic collisions. They are however dealing with the dangers of urban environments.
Replace body fat with muscle mass and you'll have found the sweet spot. Muscles need to protect and hold everything together to protect them from shock. They also provide more of a barrier.
Body fat is just extra weight, it's not going to hold up anything.
I’d wager the primary factor is how you land, whether you hit your head, etc. If you land on your buttocks first it likely wouldn’t be as bad as landing flat on your back and striking your head. Although getting that much shock/compressive force applied to your spinal cord probably isn’t great either.
Had an electric longboard and loved it. I did normal long boarding for a short time but found the electric variant much much safer because I could break much better than “slowly grind foot on the ground”
Had one crash, fractured my hand, used it for a while at very low speeds to get around my neighborhood, then sold it
Still very very fun and may get another one for my neighborhood at some point, but one crash makes you realize that, yes, you are in fact not invincible
They changed the article after I got the quote from there. You can see the original quote ("The deaths came as a result of head trauma, with at least three of the accidents happening with the rider in a helmet") in Google Search results, but if you click on the article, the sentence isn't there anymore
- Most motorcycle helmets sold in the US are inadequate DOT helmets. ECE 22.05/22.06 helmets are literally 50 years ahead of the DOT standard, but you have to specifically seek one out in the US to get one.
- Most people purchase helmets in too large a size.
- Many people do not correctly adjust the helmet straps.
1. Doesn't do a great job protecting the face or the side of the head;
2. Not designed for motorized vehicles, it can't absorb enough the kind of forces involved in these incidents.
You need a full face helmet, designed for motorized vehicles.
A motorcycle one is great, but probably an overkill (no pun intended).
There are good downhill helmets that can do the job well enough. Fox and Leatt are trustworthy brands. There are other good ones. It should be obvious, but don't trust Chinese brands.
I got a Boosted board and basically bought all protective gear and did laps around a school find all about said physics before using it as a daily last-mile transport. Helmets are so important.
This. I own two Pint Xs. Ride almost every day for three years. Had two nose dives at full speed and ran both out. I'll never upgrade to a faster model for this reason. You can't run out a nosedive going any faster. Also, the Pint X is just so nimble and fun. To me it's the sweet spot.
> This is the first thought that comes to mind: there's no way to bail, 0% chance. It's just completely not-an-option to fail on such a device at cruising speed
This is completely false. Bailing off these things at a variety of speeds is absolutely a skill you can learn. Some bails can be ran put, some are better handled with a roll or a controlled slid on your gear. Higher speeds always carry higher risks in a fall, but "cruising speed" is an individual choice and can easily be one of that you have the skills to safely bail at.
There are always risks, like in any extreme sport, but those risks can be managed with the combination of skills, equipment and good judgement.
I do highly recommend that people who want to buy a device like this take the time to learn the risks and not rush themselves to ride at high speeds before they build their skills and understand their equipment.
I had a good laugh with a co-worker a few weeks back when we saw a chick wearing sunglasses with her hands deep in her hoody pockets riding a similar single-wheeled vehicle at an intersection. Looking cool trumps common sense for certain personality types.
These sort of snide remarks are so closed minded, maybe she spent a lot of time honing her craft. I can probably ride my brakeless track bike in SF traffic with a higher safety margin than most people on a normal road bike. Don't underestimate human skill.
I know a handful of people that are absolute zealots when it comes to One Wheel and electric unicycles, riding all kinds of crazy contraptions, and doing so with incredible skill. They all still wear helmets and pads, all it takes is some wet leaves and you’re going to have a really bad day.
You sound like the people who explain that they're good drivers while using instagram on a phone because they have a lot of experience driving cars and using phones.
Which is unfortunate because one of these things has an energy of 1MJ and the other has an energy of 50kJ, claiming some sort of equivalency is totally unrealistic.
You’re right, they’re not equivalent at all. When you’re in a car you have all manner of protection around you to shelter you from injury if you crash. The other, uh
It's not about you, it's about hurting others, you're welcome to set your risk tolerance wherever you like, the problem is how your actions effect others.
That's not why, I ride without brakes because it fundamentally changes the space I am operating in. If I want to ride with a reasonable safety margin (I do) I have to think about the world in a completely different way. I enjoy that.
Think of it akin to driving a little car with skinny tires on twisty roads. You're shrinking your envelope so you can spend more time near the edges where it's fun.
Until you drop a chain with clipless shoes with clipless shoes on, so you can't even shoe brake very well like BMX riders do. I had that happen with MTB shoes on, and I completely wore down one of the lugs. I've also accidentally unclipped, before I switched to running my Time ATAC cleats reversed which I think is an old messenger trick.
And that is why I only ride my NJS frame on country roads, not in the city anymore :)
I'm a strong advocate for front brakes, but to me it seems damn near impossible to drop a chain on a fixed gear transmission. Some foreign object would need to be overlapping the chain plane somehow, which sounds like you're already crashing anyway. I think it's far more likely for the chain to outright break.
I've had it happen a few times, and on a few different bikes. Usually the cause is a chain that is too loose, and especially if the wheel is cocked to the left due to the drive side of the wheel being pulled forward from hard pedaling.
One chain tensioner on the drive side is a good preventative measure, I prefer both sides since it makes things easy.
Competence is a larger factor in safety than equipment in many cases, yes, which is why the girl is probably still alive and uninjured. Even so, I wouldn't mind having some safety equipment as a backup.
Competence is a large factor in not getting into unsafe operating conditions. Once outside the envelope, it's only a matter of time before you're unlucky.
> You can't fall onto your arms either, because your inertial speed is faster than your autonomous reflexes.
I don't understand this. Your initial spped along y axis is zero. Falling from a skateboard should be no different from falling from a standing position in terms of the time it takes for your head to hit the ground.
Your head and feet are moving at the same speed. Very fast. The board leaves you behind by stopping. You now put one foot on the ground. Because of friction, your foot stops and goes flying behind you before you can put your next foot on the ground or apply any meaningful weight to it. Because your foot was thrown backwards, it applies angular momentum to your body and you begin spinning around your center of mass (aka, falling forward). Less than 100ms has passed at this point. In the best case, your other foot is impacting the ground, right now, directly under you. But it can't take your weight before it has flung behind you and adding to your angular momentum, forcing you to go face first. It is at this point, you are capable of realizing you are going to fall face first. You have ~80ms to realize this, and put your arms up, before impact. Even if you have amazing reflexes, an impulse isn't reaching your muscles in less than 40ms, that means you need to move your arms from 'keeping balance mode' to 'defensive mode' (including applying resistive power to keep them there) in less than another 40ms. It literally isn't happening.
People who fall from standing by their own volition usually have a sense something is wrong and can fall relatively gracefully. People who are tripped from standing collapse like a sack of bricks. Same thing, you don't see falls coming on these things.
>There's many ways to fall off a skateboard without dying, and to me it's viscerally obvious, absolutely none of them will ever apply here.
As someone who's not a skateboarder but has fallen off various skis, snowboard, cycles, motorcycles etc you can fall off a fast moving thing without dying.
The usual is to kind of flop down taking the force of the fall from standing in a king of rolling motion of to your legs then arse. The main issues are you will slide along which can grate skin if you are not wearing strong clothes, and you may hit your head on something hence crash helmets. The stuff worn by motorcycle racers is probably ideal but maybe an overkill if you are going 20mph rather than 100. Fatalities are normally hitting a hard solid object at speed like a tree or similar.
The first thought that comes to my mind looking at this device is "these are failure-is-not-an-option situations". There's many ways to fall off a skateboard without dying, and to me it's viscerally obvious, absolutely none of them will ever apply here. You can't recover onto your feet, because these lithium-battery things are like 300% faster than your top sprinting speed. You can't fall onto your arms either, because your inertial speed is faster than your autonomous reflexes. (You learn all about your autonomous reflexes). It's just your face, and skull. This is the first thought that comes to mind: there's no way to bail, 0% chance. It's just completely not-an-option to fail on such a device at cruising speed. And I'm grounded enough to realize, I'm not a person who never fails physical feats. That's not what a human is.