New tyres - which end?
Discussion
joewilliams said:
I've always thought this.
However, my wife's Panda recently had two new tyres put on the front, with the original eco low-rolling-resistance tyres still on the back. Going round a damp roundabout, with no sudden change in inputs, the back end slid impressively sideways which woke up the kids
I swapped the tyres front to back, and it's back to predictable understeer.
IMHO, that was nothing to do with the "newness" of the tyres and everything to do with the fact that they were tragically mis-matched. If you had put two new eco low-rolling-resistance tyres on the front, I don't think you'd have had the kiddy-waking moment at all.However, my wife's Panda recently had two new tyres put on the front, with the original eco low-rolling-resistance tyres still on the back. Going round a damp roundabout, with no sudden change in inputs, the back end slid impressively sideways which woke up the kids
I swapped the tyres front to back, and it's back to predictable understeer.
Remember the old ad about mixing radials and crossplies? - similar effect in action here, I reckon
supersport said:
There was a program some time ago, maybe Fifth gear, that looked at this and the effect of the worn tyres on the rear in the wet was unpleasant, the FWD car over steared into trees on bends.
I am sure this has been covered on here in the past but can't remember the explanation, but it certainly made sense. Something like, the rear is likely to be the lightest and therefore needs the grip from the tyres.
it appears they may have done this test twice, i remember one with an old rwd yank carI am sure this has been covered on here in the past but can't remember the explanation, but it certainly made sense. Something like, the rear is likely to be the lightest and therefore needs the grip from the tyres.
for 99.9% of normal road users they never get near even a half the tyres limit in normal driving
in my mind the 3 most commons situations in the wet that a normal driver will come across that's affected by tyre depth is hitting standing water, emergency breaking, and emergency avoidance. Standing water and emergency braking are done in a straight line so the front tyres clear a good amount of the water out of the way of the rear wheels and in avoiding action if you cant steer out of the way because the fronts have low tread and grip your boned no matter what the rear does
Edited by Dave Hedgehog on Sunday 29th April 12:43
AnotherGareth said:
powerstroke said:
I guess you could prove or disprove anything with a "test" like that useing your own drivers !!!!
Since you're not interested in independent expert comment I'm not sure why you're contributing to this thread.Edited by AnotherGareth on Sunday 29th April 12:57
there's the expert proof 
Edited by powerstroke on Sunday 29th April 18:57
powerstroke said:
Errr what inderpendent expert comment was that ??? If you are talking about the michelin test then !!! Ok we think people should put new tyres on the back right test drivers you know what to do!! hammer into a turn and lift off in a nice low gear and when the back steps out resist the temptation to corect let it spin out job done
They will still sell the same amount of tyres, so why would they want to 'fix' the test?Edited by powerstroke on Sunday 29th April 18:54
Reading this topic, there seems to be an obvious conclusion staring us in the face:
If you're the kind of driver that regularly encounters unexpected situations (the kind that need the absolute maximum of emergency braking to avoid), then new tyres on the front.
Alternatively, if you're the kind of driver that likes to go round corners in wet weather (and your name isn't Troy Queef), then new tyres go on the back.
Sorted.
If you're the kind of driver that regularly encounters unexpected situations (the kind that need the absolute maximum of emergency braking to avoid), then new tyres on the front.
Alternatively, if you're the kind of driver that likes to go round corners in wet weather (and your name isn't Troy Queef), then new tyres go on the back.
Sorted.
My only experience with tyres and front wheel drive is with three cars:- Peugeot 205 1.8D, Citroen ZX 1.9D and a Volvo V70 2.4 Petrol.
Both French cars had bad lift off oversteer, the Swedish car maintained perfect balance. I deduce from this that it is cheap diesel cars that have a problem with the new tyres on the front.
Both French cars had bad lift off oversteer, the Swedish car maintained perfect balance. I deduce from this that it is cheap diesel cars that have a problem with the new tyres on the front.
DJ_AS said:
powerstroke said:
I guess you could prove or disprove anything with a "test" like that useing your own drivers !!!!
Gary
Always have the best tyres on the front of a car...
If its a front wheel drive car then all stress' and forces go through the front wheels and thus the most grip should be available to those front wheels.
In the case of a Rear wheel drive car then your must imagine which wheels are going to be able to collect the car car up should it start sliding? Again the front wheels are needed to point the front of the car where it needs to go to straighten it up again.
In both cases having the best tyres on the front end will be benefitial in combatting understeer.
As a final point please don't forget that all decisions about tyre placement on a car depends apon the quality of the new tyres that have just been purchased. If you have just bought a pair of remoulded rubber for 20quid a corner and still have some part worn dunlops, michelins etc then it's best to keep them on the front.
Before I hide away awaiting the comments about this post, when was the last time you saw a touring car coming in for a new set of rear tyres and leaving scrubbed fronts on?! Any good driver will agree that more grip on the front end is better.
If its a front wheel drive car then all stress' and forces go through the front wheels and thus the most grip should be available to those front wheels.
In the case of a Rear wheel drive car then your must imagine which wheels are going to be able to collect the car car up should it start sliding? Again the front wheels are needed to point the front of the car where it needs to go to straighten it up again.
In both cases having the best tyres on the front end will be benefitial in combatting understeer.
As a final point please don't forget that all decisions about tyre placement on a car depends apon the quality of the new tyres that have just been purchased. If you have just bought a pair of remoulded rubber for 20quid a corner and still have some part worn dunlops, michelins etc then it's best to keep them on the front.
Before I hide away awaiting the comments about this post, when was the last time you saw a touring car coming in for a new set of rear tyres and leaving scrubbed fronts on?! Any good driver will agree that more grip on the front end is better.
There are a lot of variables that come into the equation and it really depends on how worn down of tires you are talking.
Generally from my experience / experiments racing FF (front engine fwd) and FR (front engine rwd) cars I would rather purposely create an oversteer condition as opposed to an understeering condition and then tune my chassis to settle the rear end of the car.
A lot of time with a FWD you will have a harder time rotating the rear under heavy throttle application, so if tires were the only thing you could change I would hands down put worn tires on the back of the car any day. You could then use the brakes to rotate the front of the car and rely on the natural understeer FWD creates to balance things out.
The tighter the track the more noticeable this would become.
Generally from my experience / experiments racing FF (front engine fwd) and FR (front engine rwd) cars I would rather purposely create an oversteer condition as opposed to an understeering condition and then tune my chassis to settle the rear end of the car.
A lot of time with a FWD you will have a harder time rotating the rear under heavy throttle application, so if tires were the only thing you could change I would hands down put worn tires on the back of the car any day. You could then use the brakes to rotate the front of the car and rely on the natural understeer FWD creates to balance things out.
The tighter the track the more noticeable this would become.
Zero 1 said:
There are a lot of variables that come into the equation and it really depends on how worn down of tires you are talking.
Generally from my experience / experiments racing FF (front engine fwd) and FR (front engine rwd) cars I would rather purposely create an oversteer condition as opposed to an understeering condition and then tune my chassis to settle the rear end of the car.
A lot of time with a FWD you will have a harder time rotating the rear under heavy throttle application, so if tires were the only thing you could change I would hands down put worn tires on the back of the car any day. You could then use the brakes to rotate the front of the car and rely on the natural understeer FWD creates to balance things out.
The tighter the track the more noticeable this would become.
Fine on a track, but on a road you do not have the time and space to utilise correction methods, the tree/lamppost/ditch/guy coming the other way tends to mess it up a bit.Generally from my experience / experiments racing FF (front engine fwd) and FR (front engine rwd) cars I would rather purposely create an oversteer condition as opposed to an understeering condition and then tune my chassis to settle the rear end of the car.
A lot of time with a FWD you will have a harder time rotating the rear under heavy throttle application, so if tires were the only thing you could change I would hands down put worn tires on the back of the car any day. You could then use the brakes to rotate the front of the car and rely on the natural understeer FWD creates to balance things out.
The tighter the track the more noticeable this would become.
It's not a slight difference in grip we're talking about here, it's about the tendency to aquaplane on bends at low speeds. That kind of sudden and total loss of control isn't the same thing as a slightly oversteer-y balance.
Beware of potentially dangerous advice being given by people who don't understand the difference.
Beware of potentially dangerous advice being given by people who don't understand the difference.
kaf said:
Fine on a track, but on a road you do not have the time and space to utilise correction methods, the tree/lamppost/ditch/guy coming the other way tends to mess it up a bit.
I would still much rather correct the back end from sliding than go head first into a tree/lamppost/ditch if the car started to understeer!!S. Gonzales Esq. said:
It's not a slight difference in grip we're talking about here, it's about the tendency to aquaplane on bends at low speeds. That kind of sudden and total loss of control isn't the same thing as a slightly oversteer-y balance.
Beware of potentially dangerous advice being given by people who don't understand the difference.
So again you would rather loose all grip on the front of your car whilst trying to turn a corner?! Track driving or road driving I would the balance of grip to remain on those front wheels to get the car through the corner...Beware of potentially dangerous advice being given by people who don't understand the difference.
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