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We have really wide tyres as people buy them.
Triumph of marketing.
Anyone who does their sums and looks at replacement cost.. tends to go gray and look for smaller tyres..
Most motorists do no research.
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Anyone who does their sums and looks at replacement cost.. tends to go gray and look for smaller tyres..
The problem there is to fit smaller tyres is you need smaller wheels which puts the cost up. Plenty of places sell big wheels, does anyone sell small ones?
But since the car is Type Approved with certain tyre and wheel size combinations any changes to that would need approval by your insurance company and may cost more if they would approve you fitting them. Insurers are generally happy to let you fit winter tyres if they are on the list of sizes appoved by the manufacturer, ask to fit smaller wheels and tyres all year round and it may be a different reply.
Edited by thunderbird on 23/01/2013 at 11:54
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"and so on 3 occasions I overtook trains of 6 or 7 cars doing -honestly- 25-28mph, because I had 200 miles to do. I only mention this because, to my mild amusement, on all 3 occasions the car at the front of the train turned out to be a BMW !"
These people were driving at a safe speed you were not, 50mphplus on standard tyres over packed snow the mind boggles at your stupitity
This subject has been covered many times before and quite recently I fail to see how further discussions would make any difference.
Edited by Collos25 on 23/01/2013 at 13:03
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>>"These people were driving at a safe speed you were not"
Sorry Collos, but unless you were on that same road at the same time and in my car, you cannot be certain of that. I started out slowly and gradually sped up and wiggled about etc until I found a speed at which the car would safely travel in a straight line. I was not reckless. There was no apparent need for those other cars to be going as slowly as they were. Two of the trains were on dual carriageway and I could see the road ahead for a long way, so there was no reason any braking would be required, and the distance I could see was sufficient to stop-in anyway.
>>"This subject has been covered many times before and quite recently I fail to see how further discussions would make any difference"
Sorry again for discussing something on a discussion site. Anyway, the main thrust of my post was "from a technical perspective, is there any reason why cars nowadays apparently have to have such wide tyres?"
with the aside alluding to: Perhaps if they DIDN'T have such wide tyres, we'd all be getting along dandily in the snow at nearer 50mph than 25, and therefore have no reason to post grumbles on discussion sites.
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ave such wide tyres, we'd all be getting along dandily in the snow at nearer 50mph than 25, and therefore have no reason to post grumbles on discussion sites.
Obviously you think having narrower tyres defeats the laws of physics.
You obviously have no idea of stopping speeds in snow and ice.
People driving like you appear - or claim - to do usually cause accidents to others.
Round here they kill themselves.
But of course, you don't obviously belive that the laws of physics apply to you.
Read this and think again
tinyurl.com/bzybscq
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phew, harsh!
Your link suggests the stopping distance would be increased by a factor of 3. I had 500yds clear in front of me. And I was on snow, not ice. And it wasn't heavily packed-down and glazed, because hardly anyone had driven in the right-hand lane.
And I knew I could easily stop within the visible distance, because the surface slowed the car quite a bit just by taking my foot off the gas. And I was additionally able to achieve further retardation by braking gently, without either skidding or the ABS coming in. So you see, experimentally, I established reasonably well what the level of grip and stopping distance etc etc was, before I began to execute my manoeuvre. (and no snidey comments about 'retardation', please)
I honestly could see no reason why people couldn't drive faster than 25-28mph. Come to that, with your line of reasoning, how do you know THEY weren't being reckless, and ought to have been doing 15mph? You can't know, because you weren't there at that time, that's why.
And physics is indeed what my post was supposed to be all about. Ignoring conditions of ice. In snowy stages, rally cars wear tyres that are much narrower than they do for tarmac. They will have different tread patterns and compounds too, but it remains that they are narrower. Perhaps, then, physics suggests some benefit in narrower tyres when the surface friction is reduced from optimal, e.g. maybe also in rain, even at above 7 Celsius ??
I suppose my query thus boils down to: Is it possible that, from a physics/technical/engineering point of view, there could be a chance that the (unnecessarily?) wide tyres we have foisted-upon us nowadays, are actually less safe, in anything other than dry conditions, than they would be if they were simply less wide?
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I guess the more rubber is on the road the better. BUT, snow may require more weight per area, thus narrower may perform better. Modern car's performance bears no relation to those of even 30 years ago, never mind the E-type of 50 years ago. Many ordinary cars would out-gun that now.
The Jaguar XJ6 in the 1970s is the first car I remember specifically for its wide tyres; looked so cool!!
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I guess the more rubber is on the road the better. BUT, snow may require more weight per area, thus narrower may perform better.
More rubber on the road in the snow is not the way to get grip. Narrower will perform better, there is no may about it,
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I guess the more rubber is on the road the better. BUT, snow may require more weight per area, thus narrower may perform better.
More rubber on the road in the snow is not the way to get grip. Narrower will perform better, there is no may about it,
My 1955 Austin A30 - 40 years old , very narrow tyres and 30bhp outperformed any car on snow that was not fitted with 4wd and winter tyres.
When it came to loose snow , the tyres cut through it. And the lack of power made wheelspin rare.
Otherwise it was horribel.! But cheap
Wide tyres run over loose snow - so greater resistance and less grip. And modern cars - petrol - have little torque at low revs so many owners overrev and spin the wheels.
And many ABS systems fail to work on snow..
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And many ABS systems fail to work on snow..
ABS should work in the snow but it will not work on any car at really low speed, normally about 5 mph.
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QUOTE:...""" Nevertheless, my standard-tyred 90hp Astra was comfortable at about 50mph (in a straight line with at least 500yd visibility at all times, please note), and so on 3 occasions I overtook trains of 6 or 7 cars doing -honestly- 25-28mph, because I had 200 miles to do.""
Assuming 'quite heavy snowfall' means you're driving on packed snow, 50 mph sounds like a crazy speed to be doing when there's other cars about.
OK we weren't there at the time so we don't know the exact conditions, but 50 mph on snow is dangerous unless you're on an empty disused runway or a test track or somehere like that.
Edited by Sofa Spud on 23/01/2013 at 16:36
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On slushy rubbish snow, you want more grip so you want fat tyres.
On powdery snow narrow tyres are better because they can roll through the snow and make a nice little channel by shoving the snow out of the way.
You are more likely to aquaplane with a wider tyre because there is a lower pressure exerted by the tyre on the road, so it doesn't squish the water out of the way as well.
Fat tyres are better in the dry than narrow because when the tyre spins, it suffers less distortion because there is more of it on the ground width-ways.
I could go into a detailed microscopic discussion of friction as it is a lot more complicated than it would at first seem.....
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On slushy rubbish snow, you want more grip so you want fat tyres.
Nonsense. Narrow tyres that bite through the slush onto the tarmac will give more grip than a wide tyre riding on top of the slush.
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Skidpan: "Nonsense."
Bobbin: "I could go into a detailed microscopic discussion of friction as it is a lot more complicated than it would at first seem"
Me: Q.E.D. -There certainly do seem to be conflicting opinions about! ;-)
Sofa Spud: "50 mph sounds like a crazy speed to be doing when there's other cars about."
Me: Well, what can I say? At that time and place, I tried it out, the car was stable, I mosey'd past the other cars, nothing untoward happened. For what it's worth, further up the road, after I'd passed three trains of cars, I much more gradually caught up with 2 artics who were doing 40-43mph. I didn't bother passing them, and they turned off not long after anyway. Still no sight of tarmac though. Maybe it was some special kind of snow (?)
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I'm intrigued to hear about this RWD Škoda estate - what model was that or is my memory really that shot? You'd have to go back to the 60s models (1201, 1202 etc) to find such a beastie and they weren't imported into the UK.
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On slushy rubbish snow, you want more grip so you want fat tyres.
Nonsense. Narrow tyres that bite through the slush onto the tarmac will give more grip than a wide tyre riding on top of the slush.
No. The icy, slush type snow packs down with the weight of vehicles, thus rendering it solid. You can't push that out of the way with tyres.
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Did a similar thing driving up the M1 last week, a trains of cars pottering along at 20-35 mph all huddled in the inside lane, I pulled out onto the nice grippy snowy lane three and sat at a steady and perfectly safe 50mph.I was driving her indoors's C3 which has nice narrow all-season tyres.
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Cheers Steve - so I'm not such a heretic as I first appear ;-)
The skoda was an Estelle, not an estate. 1987 130 LSE.
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I loved the Estelle, lots of character - had a few of 'em. PS better get my eyes checked as I misread your post! :-)
Edited by SteveLee on 23/01/2013 at 18:56
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The gyroscopic effects of a higher speed with reasonable tyres in a reasonably straight line will help the car to maintain some sort of progress, so long as the surface remains smooth there's no reason you couldn't travel at maximum speed in theory.
However thats all very well till something goes wrong, one of those cars doing 25mph suddenly loses traction and slides across the road and you suddenly have to slow or stop, thats when things go wrong, you won't stop and you've put all responsibility of your too fast driving onto those other drivers to keep out of your way.
I'll tell a tale i shall try to keep short.
In a previous life i used to leave really early in the morning from Northants and travel the A45 as it was (before they tinkered with the road numbers again) then via Higham Ferrers and St Neots town and out to Cambridge.
It was a cool starlit winter morning about 2.30am, probably 5'C wet roads. Cruising at a nice steady 60mph in my empty artic as was normal in those days before the EU insisted we have lorry speed limiters, about a mile before Caxton Gibbet i felt everything go light and then a few moments later in the distance i could see hazard and other lights.
I then realised the temperature had dropped suddenly and drastically and i was travelling on a sheet of ice, it took the full mile to knock the speed off, braking other than feathering would have just induced an instant lock up (long before ABS was thought of) so out of the question.
I managed to get the vehicle slowed up but it took the whole mile of buttock clenching 'willing' the lorry to slow and when i reached the roundabout there were lorries and cars at all angles some in the ditch some crashed, my mate was there he was holding on to his crashed lorry as he could not actually stand on the sheet ice, he waved me on and i slithered off into the morning.
Now this tale isn't about me being a clever dick, its about me being exceptionally lucky to have got away with it (lesson learned) and not to have piled into those already crashed.
As the posters above commented, you might be able to keep the vehicle under control in slippery conditions at high speed, but you can't stop if you need to which means it isn't under control.
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Did a similar thing driving up the M1 last week, a trains of cars pottering along at 20-35 mph all huddled in the inside lane, I pulled out onto the nice grippy snowy lane three and sat at a steady and perfectly safe 50mph.I was driving her indoors's C3 which has nice narrow all-season tyres.
50 mph on snow whilst passing other road vehicles, absolutely crazy - how would you have been able to stop suddenly had something occurred in front of you, for example, someone decided to pull out from an inside lane in to the lane you're driving along ?
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Gordon, I absolutely appreciate what you're saying, but I just want to reiterate two points: I had experimented with how the car would slow down and could be slowed down, whilst I was still behind the last car in the train; and I genuinely don't think the conditions were such that one was required to go no faster than 28mph.
So you come up behind 6 or 7 cars doing 28mph; 28 feels slower than necessary; the RH lane is empty, but after monitoring things for a bit, you conclude that none of the cars in the train is going to venture into it: What are you go gonna do? Only two options: Either elect to (apparently) have to do your whole journey at 28mph, or attempt to overtake. After a period of experimental risk-assessment, I took the latter option.
That's what all driving is like. Assessing the risk-level of the conditions, and driving within the limits. I repeat: it was not ice. Yes, someone in the LH lane, through slippage or inattentiveness, could have come to be in the RH lane at a shorter distance than I was able to stop. The same thing COULD happen on a rainy road where the respective speeds were 58 and 70mph. Any eventuality MAY come to pass, at any moment. In the early 70s, I was a passenger in my dad's car, within the 40mph limit in dry conditions, when it was written off impacting on a large dog which ran across the road from some bushes. Unavoidable. Similar thing Gordon with your story doing 60mph on the A45 - you couldn't FOREsee that the road became sheet ice - but I bet you haven't driven everywhere at 25mph ever since 'just in case'. Where would we draw the line? 5 mph and a red flag man?
It may even have been the case that the surface in the RH lane was 'safer' than that in the left. If so, it could even be argued that the drivers in the LH lane were being negligent, and more of a threat, by insisting on driving on a more slippery surface.
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"Gordon, I absolutely appreciate what you're saying, but I just want to reiterate two points: I had experimented with how the car would slow down and could be slowed down, whilst I was still behind the last car in the train; and I genuinely don't think the conditions were such that one was required to go no faster than 28mph".
So you tested every inch of the road in reality the other car users were driving at a safe speed and you are one of the people who cause accidents because you think you know better than everybody else what is safe and what is not.I am glad I will not be in the same area as you when you are on the road.
You were lucky this time one day you might not be and harm some innocent person.
Edited by Collos25 on 24/01/2013 at 11:02
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That's what all driving is like. Assessing the risk-level of the conditions, and driving within the limits. I repeat: it was not ice. Yes, someone in the LH lane, through slippage or inattentiveness, could have come to be in the RH lane at a shorter
It may even have been the case that the surface in the RH lane was 'safer' than that in the left. If so, it could even be argued that the drivers in the LH lane were being negligent, and more of a threat, by insisting on driving on a more slippery surface.
No, you misunderstand me HC which isn't unusual given my hopeless posting style, i've overtaken hundreds of cars over the years in similar circumstances, it was the difference in speed that i was alluding to.
Iwould probably have gone by them too but maybe i'd have crept by (don't know wasn't there might have done the same as you) the problem with overtaking faster is that someone might have accidentally (or deliberately) baulked you and the 25mph differential you might not have been able to lose...the dunderhead twerp civilian who thinks he should police the roads i find is on the increase, not forgetting the legion of incompetents who beg the question how did they ever pass a driving test.
I too very often find myself driving on the uncleared section by running slightly off the main course, usually when the cleared tyre tracks have refrozen due to the salt concentration diluting following melting and you can actually see the pure lumpy black ice forming, judging by how they drive some people never actually look at what they are driving on.
In a way there are no hard and fast rules, its a case of judging as best you can and hope you've made the right call, in my tale above i made the wrong one as the sudden full icing over of the road i hadn't realised and couldn't be seen as occured almost instantly.
I do understand the frustration with people who drive too slow for the conditions, but this may be what they feel safe and confident at, the real problem is they are likely to do the most idiotic things with no forethought or warning especially if they see someone overtaking them and go into panic.
I too try to get past them if safe to do so but in doing so try to keep the speed differential in a zone i can still control...well in theory..;)
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50 mph on snow whilst passing other road vehicles, absolutely crazy - how would you have been able to stop suddenly had something occurred in front of you, for example, someone decided to pull out from an inside lane in to the lane you're driving along
There was a clear lane between the lane one lemmings and me, I've got a lot of snow driving experience, fresh snow with the right tyres affords a lot of grip - far more than those in lane one probably had on their slush and compacted ice. Also they were nose-to-tail, they were far more likely to hit each other than me hit them. And if they did pull out on me it would be their fault as it would in any other situation. I was merely taking advantage of the fact that UK is today full of wet cry-babies grasping to be nannied who would rather huddle up like lemmings on packed ice than drive on "dangerous" snow.
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And if they did pull out on me it would be their fault as it would in any other situation..
If you did any form of careful thought, you would realsie that no matter how good a driver you are, it's the other ones who are important in bad conditions.
If someone pulls out on you in normal conditions, you could brake and avoid the crash. Or acclerate. In snow you probably could not...
Driving in adverse conditions is as much avoiding the luantics as it is driving well yourself.
The question of whose fault ist is when I end up dead and injured is irrelevant to me. I want to remain unhurt and so carefully avoid passing in dangeroui conditions..
Guess I'm just an old breath of foul air .
Edited by madf on 24/01/2013 at 12:06
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Again - you are making the assentation that I couldn't stop, who says I couldn’t stop? As I said the right tyres on fresh snow afford quite a lot of grip. If someone pulls right out on you you’re probably going to hit them snow or not – and yes it is their fault. The increased stopping distance due to the conditions are probably outweighed by the reduced speeds in these particular circumstances. If I thought what I was doing was dangerous I wouldn’t be doing it. Being a life-long biker I have good road sense, a few years ago I was driving in a pack of cars in the fog, “they’re going too fast” I thought and pulled to the inside lane and dropped my speed, about 40 minutes later a sea of hazard light appeared ahead – the same pack of cars were involved in a big pile up. I repeat, I don’t drive with the lemmings.
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When you a hole stop digging.
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>>"So you tested every inch of the road in reality the other car users were driving at a safe speed and you are one of the people who cause accidents because you think you know better than everybody else what is safe and what is not."
Collos, the same thing applies to ANY weather conditions. There is a speed beyond which it is unsafe because it is too fast, and there are speeds which are unnecessarily slow.
No, I don't think I know better than anyone else what is safe and what is not. I make ongoing assessments, and drive within the concluded envelope. That's what I expect other drivers to do. Sometimes within that window I go slower, because I feel like it. Other times I wish to make good progress, so I go faster, but still within the window. I have to conclude that none of the drivers in those trains wished to go any faster than 28mph, so stayed where they were. My car felt comfortable doing more than that in their lane, and also in the RH lane, so I overtook them.
As I mentioned, further ahead, lorries were doing 40-42. I expect their drivers made similar assessments.
I was able to stop well within the distance I could see ahead. If something got in my way at a point nearer than that, that would be unfortunate, but the same scenario would apply to me or anybody else in fog or rain - with the values of speed/stopping distance/level of grip adjusted appropriately to those situations.
Nothing untoward happened, but you can't know whether that was because I was merely 'lucky', or because the conditions allowed me to do what I did despite neither me nor my car possessing special abilities.
Crikey, I only mentioned this in the first place really because I was so struck to find that the car at the front of each train was a BMW! Perhaps those behind stayed there in reverence, thinking it couldn't possibly be safe to overtake a BMW...!
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You should go on a speed awareness course you are the perfect candidate .The graveyards are full of people who thought they new best.
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Well, more snow forecast for tomorrow - hopefully I'll wipe myself out at the earliest opportunity without impediment to anyone else, and that'll be a relief, eh?
But while I have the opportunity, please can I pre-blame manufacturers for preventing us from having nicely-narrow tyres, and the government for not legislating for mandatory fitment of winter ones.
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please can I pre-blame ........ the government for not legislating for mandatory fitment of winter ones.
Why? It's not even mandatory across all of Germany, only those states where it's an issue.
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It was somewhat tongue-in-cheek, RT. If I can't blame society, it'll have to be some shortcoming of the government other than their inability to legislate against my stupidity.
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I repeat, I don’t drive with the lemmings.
Nor do I. You also have an advantage of being able to see any potential hazards far ahead of you. If you're travelling in a queue at 25mph thats fine but you'd better make sure you leave a large gap. The problem with travelling with other motorists is that you have no idea who is in control of the car in front of you. At least when you're in another lane you have some space to deal with a problem. I'd rather be driving on fresh snow than compacted ice left by other vehicles.
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Again - you are making the assentation that I couldn't stop, who says I couldn’t stop? As I said the right tyres on fresh snow afford quite a lot of grip. If someone pulls right out on you you’re probably going to hit them snow or not – and yes it is their fault. The increased stopping distance due to the conditions are probably outweighed by the reduced speeds in these particular circumstances. If I thought what I was doing was dangerous I wouldn’t be doing it. Being a life-long biker I have good road sense, a few years ago I was driving in a pack of cars in the fog, “they’re going too fast” I thought and pulled to the inside lane and dropped my speed, about 40 minutes later a sea of hazard light appeared ahead – the same pack of cars were involved in a big pile up. I repeat, I don’t drive with the lemmings.
I give up.
Edited by madf on 24/01/2013 at 16:37
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