Lock up

[zebedee]

Weird (and frightening experience) the other day, my fault totally, due to car, brakes, tyres being cold and road being cold and greasy after overnight fog. Braked coming onto roundabout and thought they had failed as car wasn't slowing. Was only when I tried to steer into a bit more space and that didn't work either that i realised i must be locked up - fortunately i just had time to release the brakes get steered, then reapply them and stop. WEIRD THING IS THERE WAS NO NOISE AT ALL FROM THE TYRES - HOW SO? And yes, they were P-Zeros!

[fergusd]

This is when your track/airfield training comes into play . . .

a) so you recognise what's happening faster
b) so you've done it before

I have experienced many brief lockups on the road in marginal conditions, but I've done it so many times now, particularly on track, that I don't think much of it, and simply unlock the wheels . . .

I think this is a very usefull skill . . .

I love wet trackdays ;-)

Fd

[Charisma]

This happens to me every day in my S2.

However I had a S1 before and found the brakes exceptional.

I would have 'gone round again' and practised it.

Just look at it as good experience, when most people do get round to having an accident it is normally when the car does something unexpected.

All drivers out there should get to know the limitations of their car, but how many grannies out there do you see 'on the limit' having a practice?

[fergusd]

Another thing worth mentioning is that I also rarely 'hear' anything much when I lock a front at speed, however I can feel it happening, but sometimes it can be subtle.

The key is not to lock the rears, as this will spin he car, you should never brake with the engine disengaged from the gearbox (pressing the clutch). Keeping the engine engaged more or less guarantees that the fronts lock first.

There's a surprising amount of detail in getting the best from the brakes in any car, the elise perhaps more than others . . .

Anyway

be carefull out there . . .

Fd

[alunr]

fergusd said: This is when your track/airfield training comes into play . . .

a) so you recognise what's happening faster
b) so you've done it before

I have experienced many brief lockups on the road in marginal conditions, but I've done it so many times now, particularly on track, that I don't think much of it, and simply unlock the wheels . . .

I think this is a very usefull skill . . .

I love wet trackdays ;-)

Fd

Managed to lock up an elise at silverstone - got the thing slightly sideways then recovered nicely. I think I learnt a valuable lesson that day

I'm doing my first airfield training day on the 27th of march so that should be a bit of a wheeze!



>> Edited by alunr on Thursday 27th February 10:11

[Feuers]

Hi Zeb,

the reason you didn't hear anything is because there was no more interaction between the tyre and the road surface - hence no retardation ! This sometimes happens on wet or greasy / low grip surfaces, when the braking force applied exceeds the available grip (obviously). Less "grippy" surfaces will always make less noise on lock up. Locking up the fronts can happen all to quickly in adverse conditions...

Regards,
Felix.