Tyre brands

BX Tech talk
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mnde
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Post by mnde »

Way2go wrote:Possibly, but ABS as a safety system is still beneficial to have and even more so if you drive towards the handling limit of your tyres and need to brake.
Hmm... on a public road or a racing track?

You could translate the above for your average Audi-driving rep:

"I can drive like a twat in all conditions because the ABS and assorted gizmos will 'sort it all out'."

I am of the opinion that all these electronic safety aids have made it easier for more and more people to drive dangerously beyond their limits, and rely on the huge grip afforded by fat tyres and ABS to be able to steam up to junctions and roundabouts, braking at the last minute, even in heavy rain. I've seen threads on forums where people argue that the driver's airbag should be replaced by an embedded spike :lol: I can see however that ABS and TC are immensely beneficial to the average driver when driving (carefully) in icy/snowy conditions, and can dramatically decrease braking distances when someone steps out in front of your car when you're travelling through town at 30mph.

Many people might argue that if you drive towards the handling limit of your tyres ... then you are driving too fast for the conditions. Not to say that I myself don't enjoy pushing either of my cars through a series of twisty B-road bends at speeds and body roll angles that would have Lucy squealing in terror if she was sitting next to me :twisted: . I'd never drive like that with her in the car.

Cheers,

Mark.
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MULLEY
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2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - SORN
1992 TZD Turbo Estate - SORN
1991 Gti 16V - Blaze - crash damaged, will get repaired - SORN
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN
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Post by MULLEY »

I didnt think ABS would help that much if you were going sideways :lol:
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

I'm not just a username, i'm also called Matthew.
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cauchoiskev
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Post by cauchoiskev »

Philip Chidlow wrote:
cauchoiskev wrote:People think that a fatter tyre will put more rubber on the road. It won't.

For a given weight on the tyre and a given tyre pressure, the contact patch area is exactly the same whatever the width of the tyre is. The only difference is the shape of the contact patch.
Uh? I can't see how this can be the case. Can you elaborate?
Contact area = weight on the tyre / tyre pressure

So the only way to increase the contact area is to increase the weight on the tyre or to decrease the tyre pressure.

Increasing the tyre width (without loading up with sandbags or deflating the tyres) only makes the contact patch shorter and wider, which will certainly change the handling, but there is still the same amount of rubber on the road.
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DavidRutherford
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Post by DavidRutherford »

Just got back to this thread. Just have to point out that this:
MULLEY wrote:The way i was looking at the tyre difference, is that at high speed, the narrow tyre will clear a lot less water, hence the tread effectively becomes waterlogged & then aquaplanes. The wider the tyre the more water it can shift at the same speed, so it doesnt aquaplane.
Is just wrong.

Tyres simply have to clear the water that is on the bit of road that they are going to use. Wide tyres have a wider contact area, and hence have to clear more water. Narrow tyres have a narrower contact area, and hence have to clear less water. The force that clears water from the bit of road in question is related to the vehicle weight. With everything else being equal (tyre compound, tread depth remaining, vehicle weight etc) the narrow tyres have to clear less water, and hence have to do less work. Because of this, you can travel faster with narrower tyres before aquplaning occurs.

As proven last night. Drove through exactly the same puddle, at almost exactly the same speed in my DTR turbo (on 165's with very little tread left) and then later in my landlords TZD turbo (195's, with about 3-4mm tread left.) The DTR carved straight through it, whereas the TZD was slowed down a little bit, and was beginning to lose grip.

Wide tyres on modern small cars are utterly ridiculous. No warning before breaking grip, and we wonder why many young drivers end up in the ditch. The same "enthusiatic" driving in a 1980 fiesta and a 2005 fiesta will see the 1980 fiesta handle like a bag of poo, but with loads and loads of warning before it completely gives up. The 2005 one will handle much better, but when it does go, you get almost no warning.

I'll stick with my 165's.
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Philip Chidlow
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Post by Philip Chidlow »

Much interesting debate. Much sense spoken too. Best advice would be to drive so you don't actually 'test' the limits of your tyres. But how do you find out where that limit is?

I have been lucky enough to do some track driving. I have never taken a BX on there however... But I think I know when I'm approaching the limit of adhesion when driving enthusiastically on the open road. I am happy with 185s on a GTi.

The crude Firestone 145s on the GSX were OK but not confidence inspiring on smooth tarmac bends - far better on loose surface and the wet. Tells me something I guess!
• 1992 Citroen BX TZD Turbo Hurricane
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docchevron
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Post by docchevron »

mnde wrote: I am of the opinion that all these electronic safety aids have made it easier for more and more people to drive dangerously beyond their limits, and rely on the huge grip afforded by fat tyres and ABS to be able to steam up to junctions and roundabouts, braking at the last minute, even in heavy rain. I've seen threads on forums where people argue that the driver's airbag should be replaced by an embedded spike :lol: I can see however that ABS and TC are immensely beneficial to the average driver when driving (carefully) in icy/snowy conditions, and can dramatically decrease braking distances when someone steps out in front of your car when you're travelling through town at 30mph.

Many people might argue that if you drive towards the handling limit of your tyres ... then you are driving too fast for the conditions. Not to say that I myself don't enjoy pushing either of my cars through a series of twisty B-road bends at speeds and body roll angles that would have Lucy squealing in terror if she was sitting next to me :twisted: . I'd never drive like that with her in the car.

Cheers,

Mark.
All that /\ !
I've said for a long time that airbags should be replaced by spikes.
I'd much rather drive a car without ABS or TC or all the other shite they throw on cars these days.
Ironically an ABS equipped car can take longer to stop than a non ABS car (if you know how to drive...).

I'm the same with driving mate, if I'm alone in the car and I know the road well I'm happy to put my foot down quite alot, but if I've got anyone else in the car I drive like an old man, really, I do, and if I've got the dogs in the car then I drive unbelievably carefully since they are uber special to me. And Misty looks at me all disapprovingly if I drive fast, bloody clever doggy!
Smokes lots, because enough's enough already!

Far too many BX's, a bus, an ambulance a few trucks, not enough time and never enough cash...
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MULLEY
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My Cars: 1999 Xsara LX 2.0HDI (90) Hatch - Fern
2002 C5 2.0 HDI (110) Estate - Jasmine - SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - SORN
1992 TZD Turbo Estate - SORN
1991 Gti 16V - Blaze - crash damaged, will get repaired - SORN
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN
x 8

Post by MULLEY »

Thread Hi-jack alert :lol:

What dogs have you got Doc?
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

I'm not just a username, i'm also called Matthew.
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docchevron
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Post by docchevron »

They aint mine, technically, I'm "uncle Chris"... they're both K's doggies.
One's a collie / Jack Russell cross called Jasmine, very much Jack Russell sized, but very bright and lovely.

The other is a Blue Murrell collie cross called Misty, mad as a box of socks but she loves me!
We did have Jess, another collie cross, she was the best dog ever, she died almost exactley three years ago, I miss her, she really was the best.
Smokes lots, because enough's enough already!

Far too many BX's, a bus, an ambulance a few trucks, not enough time and never enough cash...
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