Porsche should be selling bumper cars

[PhilDawson8270]

Surely the more sticky rubber you've got on the road, the more grip?

Nope, friction is a function of the coefficient of friction between the materials and the clamping force of them. As you increase the surface area the pressure acting as the normal force reduces as you spread it over a larger area. Thus the actual friction remains unchanged.

friction = coefficient of friction * force

The large tyres are there on high performance cars to dissipate and regulate the additional heat that is generated by high performance cars under hard use.

 

[Over The Hill]

I don't think you've understood my post - where have I proposed living dangerously, whatever that means.

You appear to want to ensure everyone has a car that can drive at a dangerous speed so that they have the ability to break the speed limit (the limit put in for safety). Most people do break the speed limit on motorways and safety is compromised.
So by giving them a car that will do over 70 - they will do over 70!

 

[marknotgeorge]

[QUOTE 4027693, member: 9609"]this is where it all becomes very complex. My Berlingo van with its 175/65s would undoubtedly stop quicker on a snowy road than a Porsche with 315/25s.
but on a warm dry day with soft compound hot tyres your false teeth might pop out in the porsche[/QUOTE]
It's still all about getting rubber to meet the road, though. Narrow tyres are better at cutting through slippy snow to the grippy road underneath.

 

[Tin Pot]

This is a thread about a specific technology, the private motor car, and its operation. If you want to start an "all laws" thread feel free.

As it happens cars are highly regulated already. I'm just asking for a tweak to that, and a bit more enforcement around it. The levels of protest this sort of thread and the suggestions contained within it seems to generate does rather indicate that petrol addicts have a real problem with their attachment to, and fetishisation of, needlessly fast needlessly powerful wantonly over the top cars.

Not really, I see it showing that those who hate fast cars for a variety of prejudices will try any bend of logic to get their way, and take cars away from people.

Luckily it not going to happen.

 

[Over The Hill]

Modern disc brakes came from racing
Crumple zone development was done in racing
Modern armco crash barriers come from racing
Seatbelts come from racing
ABS although an aviation invention, was first used on cars in racing
Superchargers came from aircraft but then through racing, superseeded by turbo chargers. These in road cars allow for amazing MPG depending on configuration
Aerodynamic improvements for economy came from racing
Electric Hybrid systems came from racing
Modern race regulations on engine size and fuel usage, result in technology being developed for more and more economic engines on the road

Of course, all this racing is terrible for the car industry. I mean, it's not like they have developed anything significant. (Sarcasm if you didn't guess). Motorsports development has made road cars, safer, and more economical. All the things people seem to want. I own a sports model Civic, but with a small engine. As I want the economy, but like the styling. Why should it matter to anybody what my tastes are?

Also, I would be interested for you to link to a UK advert of cars being raced around built up areas.

First one I can think of - there are lots.

View: https://www.youtube.com/watch?v=rClaXKtD-c8

If you drove like this you would be pulled over.

I have not said motorsport or racing is bad. And of course it is a testing ground for innovation. Innovation will continue without racing (look at how headlights have improved for example).
But really you cannot deny that many cars on the road are sold on the basis that they are linked to a racing car and promote a racing culture on the public road. The whole GTi craze was due to the appal from racing. Most motorbikes on the road seem to be replicas of racing bikes and are driven like them.
The whole culture of racing and speed prevails with many road users. Lots of people are killed as a result. There are alternatives.

 

[PhilDawson8270]

But really you cannot deny that many cars on the road are sold on the basis that they are linked to a racing car and promote a racing culture on the public road. The whole GTi craze was due to the appal from racing. Most motorbikes on the road seem to be replicas of racing bikes and are driven like them.
The whole culture of racing and speed prevails with many road users. Lots of people are killed as a result. There are alternatives.

They certainly are based on race vehicles. Superbike and Supersport racing, require the bike being raced to be available to the general public. Same with Rally, and touring car racing, and GT racing.

Don't think I'm wholly disagreeing with you. I don't disagree that things need to change, I simply disagree on the cause.

You believe changing the cars will fix it, I believe that the cars are fine, it is driver attitudes that need to change.

 

[Over The Hill]

They certainly are based on race vehicles. Superbike and Supersport racing, require the bike being raced to be available to the general public. Same with Rally, and touring car racing, and GT racing.

Don't think I'm wholly disagreeing with you. I don't disagree that things need to change, I simply disagree on the cause.

You believe changing the cars will fix it, I believe that the cars are fine, it is driver attitudes that need to change.

I think the task is very difficult and will be a long process. Certainly motor sport and road driving have been linked since both existed.

Manufacturers like racing and see it as a positive image - even Volvo get in on the act!! The racing culture is fed by the cars. The attitude is there.
I do think that if speed is not used to sell then something else will be used. Elsewhere in the world it is so. I have driven in Canada and found everyone tootles along very relaxed while in France they had a bit of a culture of making comfortable cars rather than fast cars.
I am not sure if you can sell this bike to this rider and say it is his attitude alone if he rides it fast. Surely the influence of motor sport is there and he is buying in on the culture and acting accordingly by copying.

 

[PhilDawson8270]

[QUOTE 4027888, member: 45"]I'm sure you're aware that you're being too simplistic. There's a good post on a thread here that explains it more betterer than I can. It's not just about dissipating heat.....

http://www.pistonheads.com/gassing/topic.asp?t=78848[/QUOTE]

Yes, It is a little simplistic, but it's true. The products of friction they're discussing there are very well studied in a number of academic papers about rolling resistance of objects that deform.

The friction isn't being generated though in most cases by the increased contact area, but through the deformation of the tyre. The deformation causes a resistance of rolling. That's not strictly the same as saying "greater contact patch = greater grip".

From my knowledge of drag racing, I disagree with the PH comment about tyre pressures being lowered for grip. They generate massive amounts of heat, which expands the air in the tyre. They lower the cold pressure to get a correct pressure at working temperatures. Morons in road vehicles do it because 10 000bhp drag cars do it.

 

[PhilDawson8270]

I think the task is very difficult and will be a long process. Certainly motor sport and road driving have been linked since both existed.

Manufacturers like racing and see it as a positive image - even Volvo get in on the act!! The racing culture is fed by the cars. The attitude is there.
I do think that if speed is not used to sell then something else will be used. Elsewhere in the world it is so. I have driven in Canada and found everyone tootles along very relaxed while in France they had a bit of a culture of making comfortable cars rather than fast cars.
I am not sure if you can sell this bike to this rider and say it is his attitude alone if he rides it fast. Surely the influence of motor sport is there and he is buying in on the culture and acting accordingly by copying.

I used to own a similar bike, in fact, here I am with it

I also used that bike for daily commuting 50 miles each way, down the motorway. I never broke the speed limits on it, nor did I use its performance inappropriately on the road. As I understand the risks of that attitude on a public road and the dangers. I enjoyed it's performance on the track. I couldn't afford 2 bikes at the time. These days I am fortunate enough to be able to afford multiple forms of transport and motorcycles are rarely used on the road.

I have grown up with motorsport and racing. I have raced (before smashing my arm to pieces), but that does not mean that I am irresponsible on the road. You could say I have "bought into the culture", but that does not correlate directly into being a dangerous road user.

 

[vernon]

[QUOTE 4027771, member: 9609"]an emergency stop would test this boys brakes

125mph in a petrol tanker LOL[/QUOTE]

108 mph actually knocking off a handful of mph because of overreading and it's probably doing a ton.

 

[vernon]

[QUOTE 4028018, member: 9609"]it is getting away from the car and the vid is titled 200kmh.
I'm a generous sort of bloke, I will do you a good deal here, 115 and its yours![/QUOTE]

Watch the speedo in the video - it reaches about 175 km/hr. It dial maxes out at 180km/hr.

 

[GrumpyGregry]

Not really, I see it showing that those who hate hand guns for a variety of prejudices will try any bend of logic to get their way, and take hands guns away from people.

Luckily it not going to happen.

Cars as weapons?

You could write copy for the NRA

 

[GrumpyGregry]

@GrumpyGregry, I see from an earlier post you like to spend your hard-earned on bikes. Now this is fine and dandy, and I can see how you'd want different types of bike to suit different tasks. The fact remains, though, that you've still only got one backside. Whichever one of your stable you choose, the others are going to be gathering dust in the shed, a waste of the earth's finite resources and that.

&c &c

Wasn't a bad post until the bit about the Chinese tyres.

However, pointing out that I, in my own way, have not yet overcome my own consumerist conditioning doesn't advance your cause on jot.

Two wrongs don't make a right

In an attempt to curb my bike buying habit I use a simple yardstick. Were I, an overweight middle-aged unfit man in his fifties, to catch sight of myself riding this bike would I cringe? See how shallow I am?

This explains the absence of carbon fibre pro-peleton apeing fast road bikes in my shed. And needlessly fast cars on my driveway...

 

[marknotgeorge]

Wasn't a bad post until the bit about the Chinese tyres.

However, pointing out that I, in my own way, have not yet overcome my own consumerist conditioning doesn't advance your cause on jot.

Two wrongs don't make a right

In an attempt to curb my bike buying habit I use a simple yardstick. Were I, an overweight middle-aged unfit man in his fifties, to catch sight of myself riding this bike would I cringe? See how shallow I am?

This explains the absence of carbon fibre pro-peleton apeing fast road bikes in my shed. And needlessly fast cars on my driveway...

To be honest, I don't care one jot how many bikes are in the shed. Or how fast your car is. As long as you're not being a nobber about it. Because that's the real issue: too many nobbers about.

 

[GrumpyGregry]

To be honest, I don't care one jot how many bikes are in the shed. Or how fast your car is. As long as you're not being a nobber about it. Because that's the real issue: too many nobbers about.