chiark

Lift off oversteer was easily reachable in my wife's old 1.1 Saxo at around 20mph in the wet.

They're missing the point that front tyres will wear fastest on a fwd car, though. So they're being a bit silly. It was probably well meaning though.

DavidRB

Hmm, I can see their point. It's not so much the speed that's the problem, it's the tightness of the turn. A very sharp turn at 30 might be enough to unsettle the car, but clearly at 50+, the effects are more dramatic.

That said, I hadn't thought about the issue of braking, but I would want to see that Corsa do a straight-line braking test to see how much the distance was affected by worn tyres on the front.

Even with worn tyres, my guess is that the car would still stop in under the highway code Morris Marina distances.

Modern drivers have less experience of oversteer than previous generations because they grow up driving FWD cars with well-tuned suspension that tend to understeer under all conditions.

When faced with oversteer, most people are unable to react correctly in time, whereas understeer is much easier to deal with.

It's no different (IMHO) from advising people not to mix radials & cross-plys.

Mo

On the subject of tyres....

they stated that if you are only going to replace one set of tyres you should replace the rears and leave the worn ones on the front.

To demonstrate this they showed what would happen if you were to lift off on a right hand bend at 56mph in the wet with the new tyres on the front...obviously severe oversteer and with no correction the car spun. This was then repeated with the new tyres on the rear and the car pulled back into shape.....therefore justifying the statement to fit the new tyres to the rear.

<I>So exactly how many people driving a supermini will be travelling fast enough to experience lift off oversteer?</I>

<I>What about the braking distances?</I> With worn tyres on the front on a wet road the braking distance would be greatly increased. Surely this is more likely to be an everyday scenario.

.....isn't this advice ever so slightly dangerous/misleading or am I just moaning about nothing?

Comments please............

NDT

Seems a bit unwise to reduce the grip on the end which does all the steering and most of the braking....
I would have thought that you'd still end up with problems - front end understeering under power (and giving oversteer if they lift off) and terminal understeer under braking.

GranTurismo

The fact is that for most people FWD is safe becuase they have a natural reaction to lift off it it goes a bit wrong round a bend. Thefore that part of what driven say makes sence.

However the point you make about straight line stopping is valid. I would like to know the difference then.

Personally I find a Scooby, all new SO2's and a big credit card bill to be the best solution.

longun

This may sound like a silly question but how do you recover from lift off oversteer?

Young driver having only driven front wheel drive vauhall's that only ever understeer.

P.S. I've now got a 306 and have heard that these are prone to lift off oversteer is this true?

Thanks.

S

Mo,

Within the parameters of Drivens little experiment, in my view they are bang on. I used to have a Rover 16v. Needed new tyres as the fronts were a bit kojaked so I put new on the front and left the rears alone.

In the wet, the car oversteered bigtime on a feathered throttle, for example going round a large roundabout and showed no sign of understeer.

This could be recovered from but required full opposite lock and the power kept on. If you opposite locked it and lifted off, the carwould dig in and oversteer the other way. Fun in a controlled environment but really dodgy in all other situations.

Older tyres on the front and new on the rear would cause the car to understeer which is more controlable and most mundane cars are set up to do thisd anyway. this characteristic would be magnified by the tyre set up.

Outside the parameters of their experiment, there would be the issue of increased braking distance with the worn tyres on the front.

cheers

S

robski

surely the braking distance would only be increased on wet roads?

surely the less tread you have the closer to a slick you have got, and therfore more grip in a braking type situation on dry roads?

robski

scoobysnacks

S,

A mate of mine has a Rover 216 GTI and was wondering if you know of any disussion boards for his car or performance Rovers in general? Can you help?

Don Palmer

I once ran a controlled test in a fully instrumented car changing the tyres to see what happened at limit handling speeds on a track I have driven for over 20,000 miles.

In the wet, bald all round was fun and dangerous - the car aquaplaned badly at 50 mph and became undrivable in corners. - Fantastic fun on a track as long as you went slow enough and had room to fall into when it went **** up.


Changed the fronts to new treaded tyres and went out –

The car was much worse almost spinning on the first kink in the road and failing to go round any corner at even modest speeds without gross levels of oversteer. – Much more giggling than should be proper.


Swapped the tyres front to rear so we now have wet grip at the back and bald tyres on the front.

The car under steered off the track - it became boring in the extreme to drive because it was so unbalanced – you just had to go slow enough for the fronts to grip and the rears followed like sheep.


We then put new tyres all round and drove the track almost as quick as in the dry - lovely balanced car safe and fun.


Two days later we did the same in the dry and got the opposite response in terms of balance.

LESS GRIPP is afforded by long fully treaded tyres! When they went on the back and baldies on the front the car became oversteery in the extreme. Just like a wet car with the good tyres on the front.
Swap them over and the car became understeery.

We did the same with Front wheel drive and rear wheel drive cars to very similar results

Just to put the thing in perspective the difference in these set-ups was amazing - instrumentation showed that 40 degrees less steering wheel input was required to drive the car at the same average speed (near to the limit) with the oversteery version compared to the standard car!

IE you needed far less steering input in to do the same job – provided you could control the car’s tendency to spin off into the wilderness.
This car was a nightmare to drive fast.

We have had some other memorable moments in customer cars attending the wetter the better courses.it’s an experiement that you should try if ever you get the opportunity.

Don Palmer The Wetter the Better
Anyone interested in The Bigger the Better?

Don Palmer

Long gun
specifically the advice i give is always to steer with hands on the wheel at quarter to three and never shuffle on the wheel - because you stay in touch with the front wheels.
Secondly always look where you are going or where you want to go.
LOOS only normally happens near to the limit of the vehicle's performance envelope so you will have to be going at it a bit.
suppose you are going round a corner very fast - the natural inclination is to lift off the throttle. This causes a weight transfer to the front, rear grip reduces and front grip increases. If you have already put in lots too much steering (understeer) the front wheels will take you on a tightening line - the rears on the other hand will tend to do the opposite.
The car may well spin.


My recommendation
Do as little steering as possible in all cornering situations and you will be less likely to experience gross levels of LOOS

Hope this helps

Don Palmer
The wetter the better course

longun

Thanks very much.

Now all I need is a big safe enviroment to try it out on.

Anyone own a airport?

S

scoobysnacks,

no idea of any Rover message boards or anything, only mods that mine had were to the body work and we ain't talking spoilers and sideskirts if you know what I mean

S

DavidRB

From the horse's mouth, so to speak!