Caption This for 3/4/16

Fit and forget: That is something for a new generation of engineers to work on. In fact, they are working on it, some reminiscent of the lunar rover tires.

Bridgestone airless tires

I cannot believe all of us passed up on this opportunity to mention new tech. The airless tires are apparently in Beta testing now.

'No spare tire needed'? But I drive a Jeep, the spare tire sits on the back outside the vehicle. I'd look silly with no spare back there, besides, it also functions as part of the 'damage reduction' if I get rear ended.

A guy smacked into me during stop-and-go traffic on the espressway⁽¹⁾ and I got no body damage at all, not even a bumper scratch; his hood 'underran' my spare tire, and it just flexed in conforming movement, absorbing the energy before metal touched metal. He had a nasty-looking skidmark on the top of his newly-reshaped hood, but rubber on pain should buff right out, right? And some hammer work will reshape the hood to its former glory.

Notes:

1. I mentioned in another thread that 'espressway' and 'espresso' have the same rood word, which means 'to put under pressure until the output is hot and bitter.'
   

Beautiful!!!

Unless it is the smell of burning rubber, and the sound of a woman screaming! That is why the dirty old man wears an asbestos rain coat.

Adreasler - if you want nostalgia on that jeep, you could (1) keep the inflated tires all around, (2) just keep the inflated spare, or (3) put a spare non-air tire on the back, in case of some strange damage on one of the other four.

I took the knowledge that you need left-right symmetry in pressures to be a given.

Front-back symmetry is optional, but preferred for most 'passenger vehicles,' since their weight is 'generally centered.' Cargo vehicles, like pickups or semi tractors, probably do better with more pressure in the back, to support the heavier load there relative to the 'minor' weight of the driver and engine block.

I am still trying to get past why some German auto makers recommend higher pressure on one side than the other (does this depend on which side of a sloped roadway the vehicle is to be driven?)... Then trying to fit my noggin around how airless tires would attempt to match adjustable performance factor similar to inflation of inflated tires.

Could the engineers be working out something about adjusting the springiness of the airless tires? Wow!

"Then trying to fit my noggin around how airless tires would attempt to match adjustable performance factor similar to inflation of inflated tires."

the simple answer is that the airless tires will have the response of a specific 'PSI equivalent,' and they will perform at that 'PSI' until they begin to wear out and break down, slowly 'loosing PSI' as their strut and spokes wear and age from the mechanical stresses.

I read and fully understand your points all good and valid, could have been written by myself.....

But I feel that there is a case for higher front pressures for some vehicles possibly, especially for the ones that have equal pressures all round. Because in the direction of travel, when heavily braking, emergency stopping, the front tyres can have to do up to 90% of the braking/weight transfer.

Even cornering, puts more strains on the front tyres.

I saw a program on BBC TV many, many years ago, showing tyre deformation under heavy braking and fast cornering...So I looked on YouTube and found the following clip, it really gets "good" beyond the first minute, sometimes even before the tyres start to "squeak" its quite bad.

I find that to be a good solid reason alone to use the maximum legal load pressure I feel!!

http://www.youtube.com/watch?v=ZZ1uCH9ay1k

The original Minis were for example so heavily biased to just the front brakes, that the rear brakes were almost never used (brake balancing circuit) and were often found to be rusted solid at the next MOT examination, because of this. The drivers never notice that!!

I would bet real money that many front engined, front drive only vehicles (like mine) that seldom or never tow or run loaded (not mine!), may not be as bad as the Mini was, but they are far away from being a 50:50 balance......and under braking, even that front 50 will become at least 60 I feel with weight transfer, on even the best cars.

I have replaced the front disks now 5 times in 220,000 odd Kms, the rears once only.....

Although my 4 wheel caravan tows almost level, it is in fact a tiny bit lower at the front, due to the height of the tow hitch on the car. I find this to be good for general stability (in my head anyway).

But I did notice from day 1 that the front tyres ran warmer when tyre pressures were identical all round, but not hot.

So I experimented and found that running with the rear pair at a slightly higher pressure, they took more weight (I believe) and that evened out the temperatures according to the "back of my right hand"...I had completely forgotten about this until just now!!!

What is your take on what I have said?

I know the problems with pressure gauges, it has been around since Mr Dunlop invented the pneumatic tyre!!

I believe it will NEVER EVER BE FIXED FULLY FOR EVERYONE!!

Which is probably at least 50% of the reason as to why I go mainly by temperature, though it really is a long time ago.... And my simple method is available to anyone with at least one non robotic hand and "errs" on the side of safety......

Pressure gauges are just there to get you in the ball park!! If tyres run stone cold, that indicates to me that the pressure may be too high or its a really cold day!!

I say the following, knowing that some ****** here will still "jump" on it as a reason not to do it and to tell me rudely why!! But I have to admit that over the years, as I know the German police watch for large flat areas at the bottom of tyres, to fish out overloaded vehicles, I have occasionally pumped them up a bit more, to remove some of this "flatness" and I have NEVER been pulled up for a vehicle check of this type.....it has also prevented the tyres getting too hot.

It is not usually that much, never more than 10 PSI (or the equivalent in Bar).....as I do not run overload by much and not for very far!!!

The Police in all of the many countries I have driven in, in over 50 years of driving, have NEVER EVER checked my tyre pressures either!! NOT ONCE!!!

Remember, the Police here have two special weighing scales in most police cars. Some have four, or can order a second Police car to attend!! In the UK too!! Seen it many times....

I have driven though control points, shown my documents and always been allowed to drive on!!

I once, in old Jugoslavia, nearly killed a traffic cop, his fault by the way, he apologised for giving me a shock!!

We were travelling on the awful autobahns they had then (1988?), the children were small and we had our fantastic trailer tent on the hitch.

We did not see the radar hidden in a forest, but I was driving at the legal speed (80KMH) for towing and on a long RH bend, a Policeman jumped in front of the car, I had to do an emergency stop to avoid hitting him, JUST, less than a meter from him when I stopped!!!!

He had forgotten that we had gone past, he wanted to stop a large Merc, tanking down the outside lane well behind us, which he actually did stop, while still in front of us, before apologising and letting us go on our way....

Funny at the time, but it could have gone differently......

There is another aspect of under-inflated 'soft' tyres. I had a motor-cycle and sidecar 50 years ago (Norton 16H). The single rear wheel had to provide enough traction for the whole combination and tended to get better grip when running soft. It was also a softer ride - solid frame and only springs in the saddle for suspension.

The trouble was, I had a slow puncture in the inner tube. Not too much of a problem because I carried a foot-pump. Just a nuisance really. Except on one occasion I was bumping along a rough farm track (a family day out blackberry picking) and got 'stuck' in a rut and had to rev the engine to get moving. The odd things was the the wheel was spinning but no movement.

At first I thought it was loss of grip, but no, it was the tyre itself not turning. It had gone completely flat and 'loose' on the rim, but with plenty of grip, the wheel was spinning inside the tyre.

Luckily other people were around to give us a push to back to the main road and we limped home on a flat tyre - complete with a Tupperware bowl of blackberries.

The only time to underinflate tires is if you are driving on soft sand, it helps to spread the load over the larger footprint. People who run a separate setr of tires for beach driving usually run them at 10-12# and some folks actually screw them to the rims.

That's not the only screwing going on at the beach.

This is routinely done by almost every 4WDer. I had a Subaru FF1 that weighed just 600Kg and ran conventional tyres. I could drive that car over sand dunes where only beach buggies went. I changed to radials with a wider footprint and could no longer do so, even when let down. I notice that the Ford T had very narrow conventional tyres and could go through mud and soft sand. I think it was on Hemmings that i saw a video (from an old B &W movie) showing a Chev four driving through a mine site that looked like Flanders 1917. This all begs the question, "do narrow, large diameter wheels fare better in sand and mud than fat radials?"

I don't even know how to test this question. Maybe a vintage car that still has the original wheels AND has modern wheels that can be fitted to the original hubs. Mythbusters anyone?

Jim

You are saying what I have suspected for many years.

Obviously, the wider the footprint, the lower the area pressure.

Maybe there is a best minimum "pressure per square inch" that for a specific mud, sand or grit, that should not be gone below.....Wider tyres may simply have too low a pressure per Square Inch on the ground.....

I have also had good experiences with some of my cars off road (seldom) and in snow, where many others were unable to proceed, maybe due to not having extra wide tyres? Just the standard ones...

Winter 1983, heavy snow, my BMW (rear drive) was going up hill and down dale, through masses of other cars that had ground to a halt, scattered all over the autobahn. Not the best drive/car type for such conditions I feel.....

Nothing ever stopped that car....or the driver!!!!

I'm guessing, but is it possible that narrow tyres sink lower in soft sand and mud until they get a grip on something solid. Where wide tyres 'float' and can't get a grip on the slippery surface.

My personal take is that due to the higher pressure per square inch with the narrower tyre, the ground gets compacted more and therefore more stable, aiding grip.

I have even noticed the effects on tyres that from tyre designs that have quite a fine profile, nothing like a true M+S tyre for example....

Its just a guess though!!

If you ever watch rallying you will notice that the cars switch to narrow tyres when racing on snow.

And there is also the rheological properties of wet sand and mud to consider. If the wet sand is thixotropic, then once you severely agitate it you sink (quick sand). If the sand sets up as rigid by compressing this is rheopecty (and also dilitance).

Just some points to ponder.

Sadly, we have watch the finale episode of Mythbusters last week, and they pretty much just focused on (1) blowing stuff up 500# anfo bomb inside an RV (with a high speed camera watching on), (2) rocket sledding Buster through a cinder block wall (Buster evaporated), (3) truck cow plow from hell, that plowed through 20 cars in a row, and memory lane of props from the last 14 years, and (4) blowing up more stuff with record amounts of amfo (a large cement truck). When they say "don't try this at home" they really, really mean it. One has to go to New Mexico tech testing range for bomb testing.

To answer your question: The testing has to be done on one car or two identical cars, one with straight wall tires, the other with radials, even if the rims had to be custom jobs.

The best snow tires I've ever used were the old fashioned knob treads on conventional tires. 6.50x16.00 on both my '46 Plymouth and on Mom's 41 Buick. They went through roads that no-one else was able to. I still miss those tires in foul weather.

I had to ride bicycles in the snow while delivering newspapers as a teenager. I would put knobby tires on my fat tired bike and thinking they would make good snow tires. Then this bike broke and I rode my ten-speed. The skinny tires got through the snow better. But it doesn't always work this way. One night we some weird kind of snow that was going dough. And then the fat bike worked better.

Thanks to Andy, Horace, Nigh, James and Charlie for answering my question. It seems that the intuitive use of fat, high profile, soft tires may not be the way to go for snow certainly and probably also for wet sand. We have very hungry, loose soft sand that traps the best Landcruiser and HiLux 4WDers in my near vicinity. One day when i have money and time to spare i might try this out.

Jim.

I happened to read Popular Mechanics this weekend and there was a story about "fat bikes" and how well they do on sand, snow, swamps, etc. Really supports the wider tire is better side of the discussion.

http://www.popularmechanics.com/technology/a19237/fat-tire-bikes-cycling-all-seasons/

I think it depends on the situation, thin tyres if you're trying to cut through the mush & find some solid ground, fat tyres if you're staying on top of the snow or mud.

Yup!!

The pressure rating on the sidewall is the maximum safe pressure to prevent the tire from bursting.

The pressure rating on the door sticker is the recommended pressure range for best handling and fuel mileage under a normal load, with tires comparable to the factory-issued models (same wheel and hub diameters, same 'class of tire (street/all-terrain/off-road/show/etc.).

If you've changed out the tires for something different than the factory style, say, you went with stiff off-road tires instead of the standard street tires, your 'best pressure range' for handling and fuel efficiency bay have drifted, but the best place to start, aside from hiring an Automotive Engineer to calculate the values for you, would be to start with the pressure listed on the door sticker, and watch how the tire tread wears: If the center of the tread is wearing faster than the inside & outside edges, you're overinflated and need to drop the PSI a little, if the inside & outside wear faster than the middle, your pressure is low, put more air in. If the inside & outside are not wearing evenly to each other, your wheels are out of alignment and you need to get them aligned and/or ballanced.

I have found that the door pillar sticker tire pressures are also about comfort (some would call that handling, but I think of handling in terms of vehicle performance and not occupant comfort). I will usually run mine a little 'harder' than what the factory recommends because I don't like rolling over the sidewalls when I corner plus you might get a fraction of the mile per gallon improvement due to the reduced rolling resistance. If I am heavily loaded, I will generally run the maximum pressure listed on the sidewall for the 'loaded' end of the vehicle.

My Silverado pillar sticker says 40 lbs but my tire monitors are set at 35. When I asked the dealer why they said the truck's ride is less harsh at 35.I hate it when others make decisions for me.

Same here. I much prefer to be given information, pros and cons, and then decide for myself. But you and I (and most of this forum) are not the typical appliance operator sometimes called drivers. There are drivers and there are operators.

I will always keep them at or below the max sidewall pressure (unless autocrossing but that was a past life), but generally 5 to 7 psi greater than the pillar sticker.

What's strange is that for my Mark IV Jetta (1999.5 to 2005), the sticker says 27 psi up front (way too soft) and 41 psi rear (which is bordering on too hard). I found that 35 psi up front firmed up the steering response, didn't 'roll-over' in corners and was acceptable from the comfort point of view. Any higher up front and I could not detect any handling improvement but the ride gets progressively harsher of course. I run the rears at the recommended 41 to 42 psi unless I have a lot junk in the trunk, then I might go to the max sidewall pressure of 46 psi.

My 2012 VW Touareg TDI has different recommended pressures for the front and rear with lower pressure for the front (heavier due to the diesel engine) wheels and higher for the rear (lighter) ones. Our 2014 Mercedes Benz shows different pressures for the right and left wheels. I cannot understand that being a good thing. With Bridgestone winter tires that flex the tread for traction I usually would lower the tire pressure to make a broader footprint but our old VW Bug was better at biting through snow with a narrower tire with higher pressure to reduce the footprint. As they say, "brakes stop your wheels, tires stop your car", get the best you can afford.

You and I appear to think and feel the same about our tyres on our cars.....aren't we clever!!

To keep my comments on topic, the chap in the OP, might need to be warned not to over-pressure the tyre - for liability and insurance reasons. Albeit more likely, I guess he would prefer under-pressure.

It's nice to have information to help make decisions rather than being 'told' what to do, but sometimes a decision, albeit perfectly sound, counts for nothing, when for instance caught in an accident caused by somebody else, where forensic evidence (collected by others - checking tyre pressures, etc) will be used by the insurance company to avoid paying out - and they like to pick up trivia - like tyre pressures being 'wrong' - or even 'wrong' tyres. ie, owning a ton-up car but only fitting tyres with a 70mph rating because you stay below the speed limit.

Having said that, I gather (in the UK nowadays) that 'contributory cause' has to be a factor - but it's the counter-evidence that costs time and money to collect to prove your innocence.

Just a thought.

As a PS; a magistrate colleague of mine, said if confronted by a qualified engineer expressing an expert opinion that higher pressures were safe, he would respond by saying "..as an expert you should know better. You should know the importance of complying with recommended limits"......food for thought!

I think that BSR was meaning within the recommended limits if I remember correctly....which should be fine...
He seems to be more than adept at figuring out the best pressures to use, more active than me and my cheap Jack method!!
Remember, even if pressures are upwards slightly, but just outside of the car manufacturers recommended "Pillar" sticker, it still has to be proven if that was a contributory factor or not. One is innocent till proven guilty.
When I lived in the UK, what some magistrates decided was complete and utter rubbish, but you could then elect for a "proper" trial. If that is still allowed or not I could not say....

Have to agree completely with you. Did you get them changed to 40 PSI?

I would have said to him, please put that in the contract as if I have an accident (like the Ford problems with Firestone and the Explorer), I want to know who to sue for millions of $$$$$$......

Actually, my personal thoughts on these devices is that they should show actual tyre temperature, not pressure, or hopefully both!!!

No, I haven't changed the monitors on the tires. I have a dash display switchable to the actual individual tire pressures so I don't have to rely on the alarm activation feature alone.

No temperature indicator though, unfortunately.

I found this, it checks both:-

http://www.tyrepal.co.uk/

Nice link! But that model only seems compatible with tires for "hot-wheels" cars? Just spoofing you. Thanks for sharing, bro.

LOL!!

Humour is ALWAYS welcomed by myself, even from Lyn!!

The digital readout for each tire on our VW Touareg and the MB ML350 shows tire pressure changes with exposure to sunlight, road curves, downhill braking, and speed. My wife will call home to report a tire is i# higher or lower than another and I just say drive on and it will change soon, and usually it does. I would like to see tire temperature and rpm for each since inflation pressure changes tire diameter and circumference. VW actually monitors tire rpm to warn of low pressures.

Do you watch F1 motor racing? I know they are pushing to the limit but some of the cars have thermal cameras so that you can see the temperature changes in the front tyres as they go through different corners. It's interesting to see how they heat up in a corner & cool on the straights and see the temperature gradient across the width of the tyre.

They also CEMENT the tires to the rims to keep from spinning the wheels within the tires and to keep the tires on the wheels at that speed. My diesels have a lot of torque but never that much. I once threw a tread off a biased ply tire at 120 MPH and that was not fun! The fastest I drive is about 100 MPH in the American West on those long stretches that go to the horizon. I have receipts that attest to my occasional lapses of rational driving speeds. But it keeps one alert to be challenging death AND TAXES!

Throwing a tread poses an interesting thought/discussion I had many years ago, which may or may not apply to you at that time.

The mechanic where I bought my tyres (re-treads for my caravan and trailers) supported this fully...

Running tyres under inflated, as we all know here, causes them to overheat, rapidly if driving fast.

With re-tread tyres, they buff off the rest of the old tread and "glue" a new tread on.

If the tyre overheats, the vulcanisation will at some point, release the tread to fly off as new and old rubber are difficult to stay connected, BUT, for at least a few seconds or maybe minutes, the tread-less tyre stays in one piece. Allowing you to slow down and stop.....far safer....

Its the second best part of having re-treads, the first is of course the cheaper price......But you never see them anymore, here at least......

If you have new tyres running under inflated, they usually simply disintegrate and the air is gone....not much fun either.....but worse than what generally happens to re-treads under similar conditions.

Do you remember if they were retreads or not? If it came off as a ring, it may have been a new tyre...

Truck and farm tractor tires have caps of tread applied to the body of the tire. Truck companies can lease the body and recap the tires when the tread wears down or comes off. So the trucking company does not buy the tires and can "expense" the wear part and deduct the lease portion as a business rental. Same for skid steers, tractors, and backhoes. No capital outlay but all business expense, tax deductible.

Welcome to the "nanny" state, where everyone thinks they know better than the person "borrowing" the vehicle (even though they are paying through the arse nose for it.

I hate that mentality, when others think they should do or even have the right to make decisions for their customers by default. Based on some of the apparent intelligence of the voting public these days (without making any disparaging remarks about candidates), one almost feels that the vendors may not be to blame. If the automotive manufacturers are all in Japan or Europe, (or even Korea), then perhaps they suffer from a delusion that all Americans are simple-minded, and they want to treat us as "special others" who need that extra care and handling.

"The pressure rating on the sidewall is the maximum safe pressure to prevent the tire from bursting."

The sidewall pressure on my tires reads "Maximum Inflation Pressure 40psi".

I interpret that to mean that the "cold" tire is not to be inflated to a pressure not exceeding 40 psi.

It would seem that regardless of the sticker recommendations that BSR has noted are vehicle manufacturer's recommendations apparently concerning comfort, the number on the tire wall is the governing value.

The tire manufacturer is aware that rolling resistance and /or atmospheric conditions will result in an actual pressure in excess of that value.

In Europe, that reading is considered legally only for the USA. It has no legal bearing on anything here. Never has.

I take it myself as being at worst, to be an indication of maybe 50% of the pressure needed to burst the tyre. It may be even less than that, who really knows.

Certainly, if 40 PSI cold is put in, the tyre MUST handle more than just the warming pressure increases when driven.

I do not expect that 40 PSI OK, 41 PSI BOOM!!!

This USA video demonstrates that for me rather well I find:-

http://www.youtube.com/watch?v=v_5CdWLGjUk

have you watched a tyre fitter inflating a tyre to get the bead to seal? They go way beyond the recommended pressure then deflate it to the correct value.

I agree fully, but many Americans are fixed on that sidewall pressure rating......As I already said, that rating has no legal meaning in Europe at all.....

I found this:-

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=21

If you read down, you find these interesting paragraphs:-

It is important to note that the maximum load is rated at an industry specified tire inflation pressure that is often lower then the tire's absolute maximum tire pressure. The tire pressures used to determine the maximum load the tire is rated to carry is based on the sizing system industry standards applied to the tire.

However, the tire's maximum inflation pressure may be greater, such as 300 kPa (44 psi) in this example or even 350 kPa (51 psi). This is done to accommodate the vehicle manufacturers desire to tune the tires' high-speed capability, handling qualities and/or rolling resistance to better suit the vehicle.

It is important that owners consult their vehicle's tire information placard (usually found on the driver's door or doorjamb) or their owner's manual for the recommended tire pressures for their vehicle's driving conditions.

Here you can find the following, which clears up the cold to hot inflation question:-

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=196

A tire's maximum inflation pressure is the highest "cold" inflation pressure that the tire is designed to contain.

Having had the experience in my youth of a bicycle tire blowing while inflating it, due to a defective regulator in a service station, I prefer to follow the recommendations of the tire manufacturer.

Although as another poster noted, installers inflate the tire to well over the recommended inflation value to seat the bead; note that the installers also immediately REDUCE the pressure to the maximum inflation pressure.

Also note that the tires being mounted, and the tire in the U-Tube video are not subject to the heat and stresses experienced during driving on curving and/or less than perfect road surfaces (Andy, your autobahns must be a driver's dream) as well as braking.

Just sitting in my drive the sun heated the tires in one side more than the other 40-psi on the passenger side, and 38-psi on the driver side.

As long as the tread is wearing evenly, and no excess gas consumtion is evident, I go by what the manufacturer notes on the side of the tire. Maximum speed for a given tire is also noted in the sidewall.

They invest time and money on personnel and equipment to get the best product for the money the consumer spends

That used to happen quite often in my youth, bike tyres exploding, whether it was due to bad equipment, inexperience of the use of or what ever, or even poor quality tyres, I could not say.

I heard it happen also about 10 years ago while I was filling the car tank, here somewhere in Germany, one hell of a bang!! I was probably 50 meters away and I was shaken rigid.

No harm done to anything other than the bike itself....but the kid looked a bit shocked!! (ME TOO!!)

I tend to go for inner tubes with either the French connection (Presta) or the standard Schrader car tyre connection as I never did like the ones that were around in my youth (English Pattern Bicycle Tube Valves)....but for those excellent reasons you mentioned, I have never used a filling station forecourt air supply.

I simply fill them by hand (or foot!)

But, like most bikers, as I know roughly how hard the tyre needs to be and believe that I would notice a tyre as hard as stone - just before it burst!! I like to think so....

My car tyres, are primarily blown up for me by the tyre fitter when new.

I just maintain the pressures, over the life of the tyres so to say, with my method. So I would notice if say a particular filling station showed a huge dramatic sudden drop in pressure in any tyre (which could lead, as you point out, to a possibly dangerous over inflation), when I could see that the tyre was already "in the ball park" with pressure, with my own eyes.

Its not rocket science!

But relying only on garage forecourt tyre inflation alone, I personally feel is rather like Russian Roulette!! Each to his own.

At the very least, I would use my own pressure gauge (in the glove compartment), to check after filling that they remain "in the ball park!" I am only talking about minor adjustment needed maybe 2 or 3 times a year....not even weekly....

Running too cold, when conditions should suggest that should not be, or being informed that the pressures are dramatically low, when the tyre is obviously well filled, could be dangerous...

If you release air, till the pressure is say half of normal, which I have had with both a foreign objects in the tyre and "leaky" wheels on a Mazda years ago, when I replaced the tubed tyres with tubeless! (I fixed that too with a minimum of effort!), is SO obvious.

The car loses directional stability, rather as those people who have run over a police spike strip!!! You would have to be brain dead not to notice it!!

Remember, the tyre bulges well at a low pressure, it would not be safe at speed, but it is not completely collapsed at the bottom! I could see that from 100 meters away easily, and almost daily on other cars on the road.....I visually check my tyres each and every time I approach my car, I believe that most male (and some female) drivers do. Its part of the job!!

But at the end of the day, everyone must make his her own decisions on such things, don't you agree?

I wish you uneventful motoring and biking....

"I visually check my tyres each and every time I approach my car"

Same here but I recently had the misfortune to get a slow leak in one tyre. When I noticed that this rear tyre looked a bit low, the pressure in it was 18psi instead of the normal 28, quite a drop. I initially thought it might be rim damage as it took a week to lose 10psi but it turned out to be a small nail in the edge of the tread.

Well seen!

I wonder how many others here check the tyres visually as we both apparently do.

I know my wife doesn't, I could let the air out of all 4 and she would get in and start driving, maybe only a meter or two though......

True, I can recall a couple of occasions when I've had to warn someone who was about to drive off with a flat tyre.

Yes, yes, there is a 'safety margin' built into the rating, just like an elevator is able to physically move about 150%-200% of their stated 'maximum weight' and the 'overweight alarm' is usually set for about 10% above stated maximum.

We Engineers do that all the time, because the common morons people don't stop to think about anything safety factors, they assume that if something says 40PSI that they can fill to 40PSI cold, hot, no load, heavy load, and it's 'all the same' to them. Until we dump a tone of chlorine into the gene pool to get rid of all the algae get better primary education in place to make people into better critical thinkers which the government will never do, since they're all in the pocket of Big Business these days, and Big Business doesn't want thinkers, they want a dumb, obedient flock of sheep, we're stuck having to assume that the average person out there is a mindless zombie. And if that's the 'average,' then we're giving half of them too much credit as is.

That, my friends is an example of the mindset that got America into the mess we are in right now!

Actually, the average class of people is probably what spawned you, so think about what you say about them! Also consider that these morons people that you are so eager to berate, are probably very busy out there in the real world, taking their kids to school, to soccer games, going to the grocery store, going shopping, and taking the kiddos camping on the weekends. So give them a freaking break, OK? By the way, not even 10% fall into the category of actual morons, unless you include those that insist on voting for a socialist.

Perhaps we need a better 'cross section' of Americans in the media, so we can base our averages better.

There's way too many Kardashians and Honey Boo Boos out there making this country look like the movie Idiocracy was a documentary, not a comedy satire.

I think one of your "Mindless Zombies" may be running for President right now, and doing very well. What does that say about the average American voter? We survived the "W" president, we can survive the "T" President. Since nothing gets done anyway, what does it matter?

Hey moron dude: You left out the largest American voting blunder of all time: the "B.O" President, and it really, really stinks.

Just one?

Oh yeah, Carson dropped out, and Jeb!s backers backed out on him.

Still, Donald "I want to kill the spouces and children of suspected terrorists because TRUMP! It can't be a crime, because I WANT to do it!" Trump can't be the ONLY idiot out there, even if he is the loudest.

No, I totally agree with you for once, H.C. is quite possibly the biggassed idiot of all!

Did you like the video?

A lucky find on YouTube! 150 PSI in a 30 PSI rated tyre......wow!!

We had a very serious tire accident at the airport once, The movable jet-ways have nitrogen filled tires on them. One of the tires was "flat" the three man work crew started to remove the lugs from the two piece wheel. The tire was not completely depressurized. when the remaining pressure was sufficient to snap the remaining bolts. the rim separated from the force. One man lost a leg, one was thrown over the hood of a truck, the third was knocked to the ground and unconscious.

The weight of the jet-way was great enough to bring the rim to the ground, but it still contained a dangerous amount of pressure.

As an addition to your post. Today, I read an article in the current issue of Hot Rod Magazine that covered the factory winged cars from Chrysler concerning their use in NASCAR's high speed tracks. (Daytona and Talladega)

"Goodyear placed cameras low on the cars during practice to record tire deflection at Talladega. After revealing so much deflection that it looked like the tires might come unseated from the rims, Goodyear chose not to allow the drivers to see the film, the condition was so dramatic."

How's that for a safety minded company?

WOW!!

I try to avoid cornering that fast!!

I think he did it himself, the same way you did!!!

Notice I took that "tick" off from :-

Yes, this comment is very likely to be considered to be 'off-topic'.

Note: You are replying to an off-topic comment..

.....so I am not marked as having 5 OT points!!

Only 99 years and 364.845 days of community service to go.

Oooooo....that's bad!

Not if you are only 1 month old- then it's doable.

Safety Officer (from out of frame)" Mike! You need to stand back and off to the side in case that blows off the rim... and where's your eye and ear protection!"

"Man, I'm startin' to think that one can of "Fix-a-Flat" may not be enough..."

We used to use truck innertubes for sledding. And I would pump them up by hand. I would flail away like a madman. I didn't need much pressure, I just needed to move a lot of air. And pretty soon the tube would be inflated. At the rate I was going I wouldn't have fired, I would have been promoted.

I have a dual cylinder hand pump for increased air flow since it pumps both downstroke and upstroke, for filling air mattresses and large volume tubes and toys. It works for low pressures only. The high pressure electric compressors heat the air to the point that a "cold air" inflation is hardly possible.Cold in AZ would be different than cold in CO. So we have a useless scale and recommendation system. Must be a government regulation.

Todd Hoffman and his crew get ready to begin loading pay dirt from the new cut.

Boss said, "when you're finished, you can have the rest of the day off."

LOL!!!

He forgot that I test with the back of my hand!!!

I have to admit, that did have me on the floor, rolling, inflating, deflating, and laughing!

I'd change the expression to read "RunFlat or Airless tires my a**".

With so many responses aired, it is time to re-tire this forRIM

It was getting a bit flat!

Yup, and Swazi's puns really let the air out of the conversation.

Oh great, we're starting pun threads, this topic is clearly exhausted now.

I was going to stay out of this one, but now I've just got to re-ply.

That was wheel good!

Did you not mean "REM"? Rapid Eye Movement, while sleeping?

Please explain RIM?

upper or outer edge of an object, typically something circular or approximately circular. In this case the rim of the wheel.

These late comments are from a lot of loose studs who have weakened shafts!

hub ba hub ba

The squeaky wheel gets the grease, There's the rub!