Tyres

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kafkaian
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Tyres

Post by kafkaian »

Winter's well and truly here and although this topic has probably been done to death I thought I'd resurrect it.
Recently my ABS failed and I needed a new sensor, but between being replaced and getting the parts I noticed an appreciable degradation in stopping. The front end just slid a few yards on heavy braking. With ABS of course there is no such problem.
Now a good friend of mine, who recently purchased an M reg diesel without any ABS supplied as standard, claims he does not have this problem and recently had to do an emergency stop from 40 mph without any skidding. I'm rather sceptical about this but as an explanation, do the quality of tyres really make that much difference in this respect? Or is my friend exaggerating his car's stopping ability. Will a Xantia without ABS skid whether it has Mich's, Conti's or cheapies?
I do expect some difference in performance but not to the extent that some tyres skid whilst others don't, rather just the amount of skidding. Hmmmmm
Robin
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Post by Robin »

Hmmmm, indeed. You have opened a can of worms here.
The degree to which a wheel will skid or slide does depend heavily on two principal factors. Tyre construction and the road surface naturally. Lateral skid or slide is well dealt with by tread pattern and compound however the need to remove water from the tyre footprint does compromise the forward ability to avoid skid or slide.
I would say that tyre make or design does materially affect braking distances in identical situations. So tread pattern will be a major factor on wet or greasy road conditions.
Block treads are less able to cope with greasy or wet surfaces than fine siped tread patterns equally the remaining tread will also have an effect. New tyres being better than worn.
Over to you to counter the argument!!
David W
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Post by David W »

I run my Xantia on a set of Goodyear Venturas. They were optimised for wet use in the design and handle/stop in the wet better than any other tyre I can remember in over 20yrs. I have used other tyres on a Xantia that only need to sniff wet or particularly roundabout "grease" and they would slither all over.
I noticed after first putting on the Venturas that the ABS was far less likely to kick in (wet road) as the tyre did its job so well.
Another plus side is that they reduce the bump-thump on sharp undulations some don't like on the Xantia. A small downside is a loss of absolute dry road grip and turn-in feel...would only be a problem to those pushing rather harder than is sensible on public roads.
So you are right in the closing sentence...the diferences netween tyres can be that great.
David
kafkaian
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Post by kafkaian »

Thanks guys.
Well does that question the need for greater tyre standards? If cheapies are that much poorer then surely they should not be passed ro sale? And if the tread is of importance, and maybe suited to certain vehicles, then this should surely restrict what is legal on any particular vehicle?
Hmmm, I must bow to your superior knowledge here guys, thank you. How much are the Venturas David?
kafkaian
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Post by kafkaian »

I also have to assert that my fronts are appalling from rest. I appear like a boy racer at the slightest need to get awy more quickly than usual - even with correct tyre pressures. So really, my cheapies must be bad and need replacing.
However, with resale values on these machines decreasing by the minute and my wife urging us to get an update (newer Xantia or 3 year old C5 diesel) I'm a bit loathed to commit.
However, with abs now functioning as should, I'm not too concerned
David W
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Post by David W »

I think the last Ventura was about £50-£55 fitted with valve and balance....in the older 185/65x14H size.
I think the thing about tyres is that like everything in life there will be average and better performing products available.
If folks want to put on budget tyres in 99% of driving circumstances they will be OK so that's fine.
To say budget tyres couldn't be sold because they were not as safe as a premium type would be a little like saying all 2CVs should be taken off the road because they are not as safe as a Xantia.
You have to make a choice in life...you can't always have good tyres and a nice hi-fi!
David
NiSk
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Post by NiSk »

In general, tyres made by well-know manufacturers are considerably better than "cheapies". They have better grip and are often aimed at providing a specific type of performance (i.e. they can be aimed at high speed driving on German autobahns, or wet weather in the UK, or cold conditions with either snow or ice). This is the reason why competition cars change tyres so frequently - one tyre can never be best at everything - check out the WRC events - they change tyres for almost every type of surface. Its only the well known manufacturers who have the competence (and the money) to develope such tyres, which is why no one rallying ever uses "cheapies" - you loose too much time AND reliability.
You have the benefit of being able to choose a) how much you are prepared to pay and b) how you adjust your driving style to accomodate the tyres you have bought. Just make sure you know what you want when you go shopping.
//NiSk
john alexander
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Post by john alexander »

check out viking international. I bought 4 pirelli p3000 for half the kwik fit price , they dont do fitting but a local indi did it for £20 the lot. viking do special offers,ask them whats on offer,once got conti premium contacts for £32 each. regards john.
davethewheel
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Post by davethewheel »

when the abs went off on my xantia i had the same problem is was coming into roundabouts when it was wet and sliding straight on, seems to be ok now i'm used to it.
kafkaian
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Post by kafkaian »

Thanks fellas (Each and every one of you), great advice.
Thunderbird

Post by Thunderbird »

When I replaced the original Michelin Energy XH1 on my Xantia by four Michelin Pilot Primacy, the difference in braking was amazing - it was like replacing the entire braking system by a much better one.
What surprises me more is how tyres from the same brand result in an entirely different braking performance.
simonelsey
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Post by simonelsey »

I had similair problems with a toyota carina, had slightly cheaper unknown tyres and when braking / turning on roundabout rear end would break away, and slide in opposite direction, This would only do it in the wet , Tyres lasted just over 1000 miles before getting rid of the damn things ,as it was dangerous, replaced with ATS own brand all ok . I shall never buy unknown cheap tyres again as too dangerous.
simon elsey
NiSk
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Post by NiSk »

T-bird, you've just explained the reason yourself! Michelin ENERGY are low-rolling resistance tyres, built to save fuel. Can you guess the major factor in braking efficiency? Friction, maybe? High friction = high rolling resistance. I'm not in the least surprised that two different tyres from the same manufacturer differ so much, in fact I'd be very surprised if they didn't - otherwise why would they market two types of tyre? I think the answer is pretty obvious - they are aímed at different market segments. You can't have low rolling resistance AND high friction in the same tyre - it's physically impossible.
It's the punter who decides if he wants an "economical" tyre or a "sporty" tyre.
//NiSk
Thunderbird

Post by Thunderbird »

Nisk,
I follow you 100%! I will just slighty touch your final sentence:
It's the punter who decides if he wants an "economical" tyre or a "sporty and safe" tyre. [;)]
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