SAFETY

[ddk]

Bought bar end mirror
Fitted mirror
Rode two miles
Removed mirror

Absolutely, 100% useless!

Leaving aside the issue that it moves in the wind at 30mph, the image at any speed on any surface is so blurry it's impossible to discern anything to the rear. I think I saw a pair of car headlamps following me in the gloom, but it could have been anything.

see... you bought the wrong kind of mirror


I haz the right type

a reflection on me

my mirrors.jpg (24.83 KiB) Viewed 379 times

[cal3thousand]

The mirrycle is a pretty good mirror too!

I have it an it does not move at speed. Granted, I only get 30 mph if it's downhill

[Punx0r]

I love the ghetto instrument binacle

[HAROX]

.

[Alan B]

Mirrycle bar-end mirrors get high ratings. I have several. Vibration in the bike reduces the utility. Works really well on bikes that don't vibrate. Works even on bikes that do vibrate, but less clarity. Mirror is convex which helps.

[The fingers]

The glasses mount mirror is popular, I always wear glasses anyway for eye protection when e-biking.

[Alan B]

A fuse on the battery mains. Very few have them, but everyone needs them.

As we see from chroot's recent experience, a fuse on the mains may not be enough. Any wiring from the battery that can sustain large currents needs to be considered for fusing. Charging lines, even balance lines if they are heavy enough to generate fire-starting heat.

viewtopic.php?f=14&t=41877

[ddk]

LOL
what I mean by using the words "I haz the right kind of mirrors"
is simply that those mirrors work for my particular application
All bikes and their riders are different
some, more so than others

lowrider mirror2.jpg (46.03 KiB) Viewed 334 times

The head-mounted mirrors don't work for me because I'm old and my eyes don't refocus so fast no mo' This is true about everyone over about the age of 42 where the older you gets the longer it takes.

Basically a mirror is very much user-dependent, so choose wisely user. Don't neglect using them as they can save yer a**fault

[Jeremy Harris]

A fuse on the battery mains. Very few have them, but everyone needs them.

As we see from chroot's recent experience, a fuse on the mains may not be enough. Any wiring from the battery that can sustain large currents needs to be considered for fusing. Charging lines, even balance lines if they are heavy enough to generate fire-starting heat.

viewtopic.php?f=14&t=41877

There are certainly some useful lessons there. I'm not sure about adding lots of fuses though, as I suspect it may well cause more hot spots (and hence potential fire initiation points) inside the pack. Fuses do have an appreciable loss, often they will have a few milliohms of resistance, so it would be easy to get the fuse resistance up to the equivalent to the motor winding resistance in some cases, leading to a lot of heat build up inside the pack (and a lot of lost power).

Perhaps we should take our cue from the way that big automotive battery packs are protected. The Prius pack, for example, has no internal fuses, just a large fuse outside the pack. What it does have internally is really solid cell mounts, designed to not only hold the cells firmly in position and prevent chafing from vibration, but also to withstand a significant amount of crush damage in an accident. The battery and cell wiring is also exceptionally well protected and secured.

There are too many ebike packs around where the assembler hasn't paid enough attention (in my view) to preventing the cells, wiring, BMS etc from chafing and vibration-induced failure. A fuse is a nice secondary protection system, but it would be better (in my view) to prevent the fault occurring in the first place. The cells themselves, even cheap ones, are usually pretty safe, it seems to always be the installation that creates the major failure risk.

[Alan B]

If you have only one not lead running away from the battery, then only one fuse is needed.

Physically anchoring battery, using proper wire, protecting insulation - good practices.

Prius's don't have balancing and separate charging leads, I suspect. I seem to recall that standard good practice calls for a fuse within a few inches of the battery. But having discharge leads, charge leads, and balance leads is essentially bypassing this practice if only one of them is fused.

If you have only one hot lead running away from the battery, then only one fuse is needed.

[Jeremy Harris]

Prius's don't have balancing and separate charging leads, I suspect. I seem to recall that standard good practice calls for a fuse within a few inches of the battery. But having discharge leads, charge leads, and balance leads is essentially bypassing this practice if only one of them is fused.

If you have only one hot lead running away from the battery, then only one fuse is needed.

Yes, the Prius does have balance leads, lots of them. Strictly speaking they are sense wires that go to the battery ECU, plus they aren't at the cell level, but at the cell module level, so there are "only" 28 cell modules to sense, rather than 168 individual cells. There are some photos of the pack here: http://www.hybridinterfaces.ca/stockNIMH.html .

Protection is by a single fuse plus a safety disconnect that is fairly easily accessible in the event of an accident, another good idea for safety in my view.

[Alan B]

Perhaps they provide other forms of current limiting on their "sense" wires, or they don't care since melting sense wires don't present a danger to the Prius batteries. That doesn't mean that technique applies in the ebike situation.

Many ES builds have balance leads coming out to one or more connectors. These wires are usually small gauge, so perhaps just depending on them to vaporize if they get shorted is okay. Still, that's white-hot liquid copper dripping in close proximity to the batteries, and many batteries are not well protected against that.

People with large gauge balance wires have a much more significant risk from shorts therein. Current limiting near the battery could prevent a sad day.

Small picofuses very close to the battery could protect the balance leads without much volume. In one case I made balance paralleling circuit boards with thin traces on purpose to make fuses that would protect the battery balance leads. One day a momentary short vaporized the PCB trace with no fanfare at all, didn't even know it happened until it was noticed later.

[Jeremy Harris]

Perhaps they provide other forms of current limiting on their "sense" wires, or they don't care since melting sense wires don't present a danger to the Prius batteries. That doesn't mean that technique applies in the ebike situation.

Many ES builds have balance leads coming out to one or more connectors. These wires are usually small gauge, so perhaps just depending on them to vaporize if they get shorted is okay. Still, that's white-hot liquid copper dripping in close proximity to the batteries, and many batteries are not well protected against that.

People with large gauge balance wires have a much more significant risk from shorts therein. Current limiting near the battery could prevent a sad day.

Small picofuses very close to the battery could protect the balance leads without much volume. In one case I made balance paralleling circuit boards with thin traces on purpose to make fuses that would protect the battery balance leads. One day a momentary short vaporized the PCB trace with no fanfare at all, didn't even know it happened until it was noticed later.

It really depends on the risk analysis. If you make the connections so secure, safe and well-protected that the chance of a short is near-zero, then there's no real merit in fitting lots of fuses. On the other hand, if you have the sort of build quality that seems typical for many ebike packs then fuses on the balance leads, close to the cells, might be a good idea.

It all comes down to this balance of risk, and I'd suggest that building packs robustly, with good quality connections, insulation and mechanical construction may well make adding fuses to the balance leads unnecessary. The problem is getting people to understand the risk factors and how to best build packs that reduce these to an acceptable level.

[John in CR]

.... The problem is getting people to understand the risk factors and how to best build packs that reduce these to an acceptable level.

That's asking a lot. They insist on helmets, but don't wear full face helmets when the majority of serious cycling head injuries have always been injuries to the face. Heaven forbid someone not wear a helmet to take a bike to a nearby store, but only an idiot would wear a helmet to walk to the same store despite the fact that walking on the sidewalk is more dangerous over the same distance.

[Jeremy Harris]

.... The problem is getting people to understand the risk factors and how to best build packs that reduce these to an acceptable level.

That's asking a lot. They insist on helmets, but don't wear full face helmets when the majority of serious cycling head injuries have always been injuries to the face. Heaven forbid someone not wear a helmet to take a bike to a nearby store, but only an idiot would wear a helmet to walk to the same store despite the fact that walking on the sidewalk is more dangerous over the same distance.

It's a universal human failing, the inability to assess risk with any degree of proportionality. We see things like daft new laws created to reduce miniscule risks (like local authorities not allowing hanging flower baskets in the streets because of the risk they might fall and kill someone), whilst really dangerous activities (like horse riding, which here kills and injures more people than pretty much any other leisure activity) are ignored..............

[The fingers]

Things people do may seem right to them. Others may view those actions differently.

[amberwolf]

We see things like daft new laws created to reduce miniscule risks (like local authorities not allowing hanging flower baskets in the streets because of the risk they might fall and kill someone), whilst really dangerous activities (like horse riding, which here kills and injures more people than pretty much any other leisure activity) are ignored..............

I am pretty sure this is due more to wish to avoid litigation issues than it is to prevent harm. At least here in the USA, it is highly likely someone would sue over a flower basket falling upon them out of hte sky, but less likely that they would do so if they were injured during horse riding. Plus, the horse riding if done at a place specifically for this commercially will have a waiver they must sign, absolving them of responsibilty and placing it upon the rider; there is unlikely to be such a waiver for walking down a street with hanging decorations.

It is unfortunate that the lawyers (and those that turn to them first over anything that happens) have created such a society, that does not attempt to prevent harm, but rather attempts to prevent events leading to litigation. Otherwise there would be more education, specifically about how to pay attention to the world around you, check things before using/doing/etc., and to stop and step back a moment before doing anything to see if it might be stupid and get you or someone else hurt. I know that won't happen, but it would prevent a lot more than anything else that people have tried.

[Jeremy Harris]

You're probably right, AW, except here waivers aren't legal and have no standing in court, so there's no way to remove responsibility by getting someone to sign a bit of paper. Personally I think that's a bad thing, because we're now getting a compensation culture, driven by greedy lawyers, that's similar to that in the US. I was sat in the doctors surgery last week and they even had adverts on the wall there from claim-seeking lawyers (and we have free health care here). It seems that few people are prepared to just accept that shit happens, and sometimes no one is to blame, everyone always wants to use misfortune to try and make money from someone else.

[The fingers]

lawyer pronunciation: li-ur
I asked my lawyer if one could practice law without telling lies, and he responded "I could answer that question, but I'd have to lie to you."

[evildave]

I'd be interested in seeing the study that says walking's more dangerous than biking.

Me walking 5MPH, and being able to stop and turn and dodge instantly, even jump and climb, and always waiting at crosswalks, and superb overall situational awareness...

Versus a bike going faster than you could ever run, that you may have to operate part-time among motor vehicle traffic. It can't stop instantly without spilling you. It can't dodge sideways or change directions as fast as a pedestrian can, at least not without spilling you. The faster you go, the less you can hear, and the less time you have to react to things.

I've never sustained any memorable WALKING injuries, especially not to my head... but I've spilled off a bike memorably enough, often enough.

Though the faceplant was awful (fork failure), and the bloody hamburger road rash to my face was unsightly, and the braces that saved my teeth were a nuisance, the separate incident with the injury to the back of my head that made me BLIND for most of the rest of that day was a lot more terrifying.

If there are 'more' face-first falls than other kinds of falls (citation?), cumulatively, there are more falls from all other directions combined than face-plants, alone.

I am having an awfully hard time finding any useful statistics for 'where' on heads traumatic head injuries from bicycles happen most often, though site after site reports that head injuries are the leading cause of bicyclist deaths, and helmets probably would have prevented numbers like '85%' of them. Overall, a helmet for a bike, scooter or skateboard would probably be a wiser investment than, say, knee and elbow pads. Even a two foot fall can crack your skull.
http://www.headinjuryctr-stl.org/statistics.html
http://www.aans.org/Patient%20Informati ... njury.aspx

Even if the facial protection from bike helmets is somewhat laughable, I'll keep the 270 degrees of protection to the back and sides to my head, anyway.

There are always things that the helmet won't protect you from. It's not magic. Crushed by a bus? 40+MPH into concrete wall? Over a cliff? Into a wood chipper? Yeah, the helmet probably isn't going to help much. Maybe they'll know which part of the gore to start looking for the face in, as they scrape you up and put you in baggies, but not much help to you, personally.

Nothing will replace caution and patience. But those two things only go so far. Shit happens, and sometime that helmet could make the difference between a rough afternoon cussing about your bent bike and barked arms and knees, and a rough lifetime of TBI 'recovery'. Maybe even between days in a hospital and long time in a box.

My dad actually has a good snappy come-back to the fatalistic 'just my time' argument from my brother and his Vespa (editing out the 'gayness' arguments about it).

"Maybe it's just your legs' time."

O'course, then you can soup up your electric wheelchair....

[John in CR]

evildave,

I'm simply not getting into the helmet debate again to educate someone who won't listen anyway. It's a simple fact that the rates of fatalities on bicycles don't go down per rider with the implementation of helmet laws. Find out why yourself, but the major causes are that behavior changes with the safer feeling of a helmet (normal human nature just like you'd walk more carefully along a cliff than on a city park path), and real safety issues, techniques, and instruction go by the wayside.

Since helmets obviously must increase survival chances in the event of an accident, yet fatality rates don't go down with increases in helmet use, then obviously wearing a helmet must increase the odds of getting into an accident.

Helmets aren't safety equipment except in activities like racing and off road riding, where crashing is a given. They're insurance. Cycling can be such a safe activity that the odds of a helmet paying off indicate that you should wear put a helmet on for all activities as soon as you get out of bed. Staying safe on the road is accomplished using what's between your ears, not what's on your head, yet as always threads like this go to equipment, not how to ride and techniques for staying safe.


Regarding walking vs riding. It's simply because you're out there for longer. It's statistically safer per mile by bicycle than walking.

[hjns]

Hi John,

Although I like seeing you handling the statistics, I do not agree that wearing a helmet is for insurance only. Regardless of my chances of to get an accident in general or a fatal accident in specific, I do not only feel more safe when wearing a helmet, I also have the experience that it is more safe, having fallen several times where my helmet protected me.

Therefore, safety can not only be evaluated by the number of fatalities or recorded accidents. It should also be assessed by the number of non-fatal non-recorded accidents where the helmet actually did the job and protected the rider from serious injury. Now, I agree that almost by definition we can not assess safety in such a way, which is why we then fall back to discuss individual experiences.

I did not start out with this attitude. I thought wearing helmets was ridiculous. When I got kids, I wanted them to wear helmets when biking. For safety. That's when I needed to set a good example and wear a helmet as well. Then it got me thinking, and now I will wear a helmet for the above described reasons.

[evildave]

evildave,

I'm simply not getting into the helmet debate again to educate someone who won't listen anyway.
...

It's also a really, really simple fact that hitting your head sucks.

A helmet gives you a good chance that such an event will not suck quite as much.

You're obviously from the 'Helmets are evil, and I won't ever listen, but will tirelessly try to convince people to never protect their brains from impacts in any way, and I will never cite any study at all!' camp.

You can carefully shop for a helmet, find one that combines the best attributes for low to moderate impacts versus weight, comfort, price, etc., and wear it. You know, do some homework.

Or you can blindly, madly insist that wearing a helmet will cause some sort of super-mega-death implosion if it contacts anything while you're wearing it, and blurt half-remembered nonsense you heard from some tin foil hat wearing nincompoop about some obscure, twisted 'study' that upon being peer reviewed, was laughed out existence, except for helmet-hater web sites.

Oh, and never, ever back up a word that you say with any hard science. Because 'google' takes too long.

Helmets are for brains that are worth protecting.

Regarding walking vs riding. It's simply because you're out there for longer. It's statistically safer per mile by bicycle than walking.

As for that personal opinion of yours that 'walking takes longer, so it's more dangerous'?

Don't walk anywhere! Run! Running must ABSOLUTELY be safer than walking by this 'reasoning'. Nobody ever gets hurt running anywhere, where they could have walked, because it took less time!

Looking both ways takes more time! Just cross the street at a dead run, without looking; it's SAFER!

Run with scissors! You won't be holding them as long, so you'll be less likely to cut yourself!

Run around the pool, because you won't spend as much time near it, so you'll be less likely to slip, hit your head, fall in, and drown than if you walked carefully and spent more time near the pool!

Ride (and drive) as fast as possible, EVERYWHERE! Speed limits are murderous traps! Limit the time you spend on the streets where you might have an accident by going 100MPH wherever you go!

The bathroom is statistically the least safe place in the home (more people have accidents there!) So be sure and run in, finish ALL bathroom business in as much a hurry as you can, and RUN BACK OUT AGAIN! HURRY! YOU MIGHT BE KILLED BY BEING THERE!!!

Don't sleep on your bed. That's another place people die very often. If you spend less time in bed, you'll never die in your sleep!

[evildave]

In fact, now that you have me ranting, I can't think of a single thing that GOING FASTER won't make 'safer'!

Chopping the vegetables? Less time = less exposure to the knife! Box cutter? Same deal!

Power tools? Less time = less exposure to power tools!

OK, I'm sort of driving that into the ground, and I'm sorry if you don't really deserve any of that, but I am an @$$hole.

I suppose we could underline one nice tenet of safety: Take your time!

Rushing around, trying to shave minutes off your trip can shave decades off your life. Or at least the part of your life that you could get around on your own, without help.

A bike is made to carry you at a 'running' pace over a moderate distance, much longer than you could run. Most people can't run a four minute mile, but they can beat that pretty easy on a bike.

Trying to make your bike faster, so you can ride faster all the time, might not be such a great idea. All kinds of parts of your bike aren't made for high speed, including the frame and fork. If you're going faster than 15MPH or so, your bike helmet will probably be of less help in an accident.
http://www.bhsi.org/limits.htm

If you do go faster, then buy a better helmet. Maybe a moped helmet? Maybe a DOT certified lightweight motorcycle helmet with some kind of venting.

This isn't to say that a motorcycle helmet will save you, if you're going 60MPH and crash squarely into the back of a stopped truck. That's quite a bit outside even what a motorcycle helmet is designed to protect you from. It handles reasonable loads from collisions and impacts at the kinds of street speeds you spend most of your daily life doing, at the riskiest points in intersections where you stop and go and turn. It can be the difference between 'all racked up' and 'organ donor'.

[John in CR]

Insults and sarcasm is all you have, because there is no hard evidence, and you can bet your ass if there was then the helmet pushers (lead unwittingly or knowingly by the equipment manufacturers) would know the statistics by rote. I'm no helmet hater, and I actually wear a helmet sometimes, ie when I perceive the risk of accident to be higher than normal. Go ahead and keep spewing the cute little comments you picked up from other helmet preachers, and since you think you're so smart, try explaining why cycling fatalities per capita haven't gone down with increased helmet use.