Run Flat Tyres

thepharcyde · 7 Aug 2006 at 08:10

I was drving home yesterday, and the tyre warining came on on the dashboard. Immediately think great £150 etc. But I dont think I have a puncture. I was changing lanes approaching a roundabout, and their was a slight camber between the two lanes, and i have read in my manual that this could cause it to trigger. Because the way it works is it monitors the speed of all the wheels, and if one slows down it says you have a puncture. Anyway I have reset and done over 30 miles since and the light after I reset has remained off.

My concern is that you cannot tell you have a puncture with RFT, is their anything else I can check bar looking at the pressures, which if one is 2 bar down paranoid me will think it has a puncture?

Cheers

thepharcyde · 7 Aug 2006 at 09:58

anyone?

MrMatteh · 7 Aug 2006 at 10:04

2 bar down? or psi?

if it is bar, im'm gonna go out on a limb here and say its got a puncture

NickXX · 7 Aug 2006 at 10:17

Lol, 2 bar is definately a puncture. If it's 2 psi, then pump it up to the correct level, and do the same with the others and see if it loses pressure at the same rate as the others. If it's losing it much quicker you probably have a puncture - this however may be repairable.

thepharcyde · 7 Aug 2006 at 11:41

NickXX said:
Lol, 2 bar is definately a puncture. If it's 2 psi, then pump it up to the correct level, and do the same with the others and see if it loses pressure at the same rate as the others. If it's losing it much quicker you probably have a puncture - this however may be repairable.

Sorry it was a matter of speech. I have not looked at them incase one is slightly low and I get paranoid.

bullit in head · 7 Aug 2006 at 11:54

I have not looked at them incase one is slightly low and I get paranoid

now that is just asking for trouble...idiot

bullit

timbob · 7 Aug 2006 at 11:57

Doesn't have to be a puncture - could just be the tyre not seated properly on the rim, leaking a little air.

thepharcyde · 7 Aug 2006 at 12:00

bullit in head said:
now that is just asking for trouble...idiot

bullit

No I would be an idiot if the light has come back on, no need for a sarky response like that mr! The car is new to me with the first time of using RFT, non of them look flat. The reason I have not used an air line is, because air does slowly seep though the tyre walls, so if it was down a couple say 30 instead of 32 that would make me think its a puncture paranoid as that may seem.

So Bullit any thing constructive to say as to how to test a RFT for a puncture just to make sure because the light has remained off.

Nothing to add then click back on your browser please

thepharcyde · 7 Aug 2006 at 12:01

timbob said:
Doesn't have to be a puncture - could just be the tyre not seated properly on the rim, leaking a little air.

But the light would come back on right? Reading the manual you have to disable the system when using snow chains etc, because of slip. The light would have come back on withing the 50 miles I have done now since it happened right?

Rich1988 · 7 Aug 2006 at 12:03

thepharcyde said:
The car is new to me with the first time of using RFT, none of them look flat.

RFT dont look flat even when they have no air in them, thats how they work they have such strong sidewalls.

Oakesy2001uk · 7 Aug 2006 at 12:06

Rich1988 said:
RFT dont look flat even when they have no air in them, thats how they work they have such strong sidewalls.

exactly why they weight a ton and make cars handle like a bag of poop, I wouldent touch them with a 10 ft barge pole, but yes the dont look flat so you have to check them.

TripleT · 7 Aug 2006 at 12:42

As said, just go fill them all to the correct level and check them in a week to see if there's any change

P.S - I thought that RFT couldn't be repaired if they got punctured?

Oakesy2001uk · 7 Aug 2006 at 12:48

TripleT said:
As said, just go fill them all to the correct level and check them in a week to see if there's any change

P.S - I thought that RFT couldn't be repaired if they got punctured?

you would think so wouldent you??

just seems to me like they have no benefit they get you home after a puncture, big whoop thats what the spare is for! They say safety, but how often do blow outs happen at dangerous speeds with quality tyres that arent knackered? not often I'd be willing to bet.

TripleT · 7 Aug 2006 at 12:58

Oakesy2001uk said:
you would think so wouldent you??

just seems to me like they have no benefit they get you home after a puncture, big whoop thats what the spare is for! They say safety, but how often do blow outs happen at dangerous speeds with quality tyres that arent knackered? not often I'd be willing to bet.

Tend to agree with you. I was talking to the guy who put my new tyres on the back (NOT RFT may I add

) and he was just laughing at them and called them a joke really.

I suppose from BMW's marketing POV they're good. BMW being a "premium" brand, majority of drivers probably aren't the ones who'd like to have to get on their hands and knees and change a tyre

Or they're just rep's who get tyres from the company

RFT's aren't fitted to the M cars are they?

Simon · 7 Aug 2006 at 13:01

If the tyre deflection in a corner is great enough then it could think the tyre is flat I guess.

Pretty sure it is linked to a steering angle sensor to avoid this during normal corners though.

Oakesy2001uk · 7 Aug 2006 at 13:02

TripleT said:
RFT's aren't fitted to the M cars are they?

I doubt it, the M dept wouldent let them anywhere near I hope, you would have to have magneium or carbon wheels to negate the extra weight of them in the handleing, even then the fact the weight is spread around the edge of a large rim make the gyroscopic effect even worse. Unsprug weight = bad!

thepharcyde · 7 Aug 2006 at 13:37

Sorry, to drag this out, but what I am trying to explain. It can sometimes be enabled if the wheels slip, cambers etc this is what it says in the manual. I just want to know that if I have reset the warning, if I did have a puncture then surely the light would come back on right? I will take it to the garrage tonight and pump them up, I just think its pretty crap you cannot visually see if you have a puncture. How many people have had the airbag flash on, only to be a faulty sensor? I am thinking it is a rogue case.

Simon · 7 Aug 2006 at 13:39

Parents mini does it quite a lot. Quick reset using the reset button on the handbrake surround soon puts the light out. The fact there is a button for it suggests it happens a lot.

thepharcyde · 7 Aug 2006 at 14:20

Simon said:
Parents mini does it quite a lot. Quick reset using the reset button on the handbrake surround soon puts the light out. The fact there is a button for it suggests it happens a lot.

Thank you Simon, this is what I thought.

Cheers