Run-Flats ? Repair or Change

[yky]

My friend's E90 is shod with run flats all round.
PML advises against doing patching if one of the tyres get punctured, but to replace the tyre...almost $400 per tyre!!! Quite expensive for simple nail / sharps injuries.
What is the general opinion? Do a $10 patch repair job or go for a $400 replacement tyre?

[yendor]

IMO, patch up the bugger with an internal vulcanising patch and drive until tire botak or no flower, then change to normal performance tires....

[BZSAB]

Interesting! I was told the cost of replacement is about $200 each.

[yky]

No man. I was told by the salesperson yesterday ( I was with friend when she collected the new 320i from PML ) that the run flats for the 3 series is about $400 going up to almost $800 for the 18 inch.

OK, we patch it up if it kenna a nail / screw. But would that make the tyre 'non run flat' anymore? Can any 'ordinary' neighbourhood tyre shop repair runflats or must go to specialist ones like Stamford, etc.

If u remember Yendor, I ( 730i ) changed the diff / engine / trans oil to Torco and the plugs as well the other evening at UM2. Very smooth, free reving and quieter and the gearchange feels much 'softer', can't really put it in words, but it was well worth it. Can't feel much change in throttle response though...heavy car.

[zag]

Originally Posted by yky

No man. I was told by the salesperson yesterday ( I was with friend when she collected the new 320i from PML ) that the run flats for the 3 series is about $400 going up to almost $800 for the 18 inch.

OK, we patch it up if it kenna a nail / screw. But would that make the tyre 'non run flat' anymore? Can any 'ordinary' neighbourhood tyre shop repair runflats or must go to specialist ones like Stamford, etc.

If u remember Yendor, I ( 730i ) changed the diff / engine / trans oil to Torco and the plugs as well the other evening at UM2. Very smooth, free reving and quieter and the gearchange feels much 'softer', can't really put it in words, but it was well worth it. Can't feel much change in throttle response though...heavy car.

just wondering how would a run flat become non run flat just becoz one put a patch on it.

I think the whole thing about runflat tyres has consumer misinformed etc. etc. and PML also could not give you a good reason for not repairing a run flat.
imho Run flat tyres basically has stiffer side wall such that in case of puncture and loss of air pressure, the stiffer side wall can sustain the car weight and run at mild speed with no safety being compromised. Good thing about run flats when you are doing 150kph and boom! the tyre went.. the runflat will safely tread the speed down till you stopped safely.

Now back to topic. the only reason i can think of for not repairing a run flat is after a puncture and one continues to drive the car for a considerable distance till the next workshop as such the tyre characteristic particularly the side wall has changed and manufacturer deem it unsafe to be used again.

anyway.. i think run flat still sucks until the next generation when they improve, noisy and all but i like the stiffer side wall giving the crisp steering feel. 18" run flats cost $500 only nowadays for the lousy dunlop or better B/stone.

[yendor]

The run flats has very stiff side walls to keep some tire height even though there is no air. Patching will not degrade the run flat performance. "Tire Specialists" is very subjective matter. There is basically 3 methods to patch a tire:

1. Insertion of a sticky rubber thread about 5mm in diameter and 10cm long through the puncture. This is done from the outside and the man will stand over the tire and use a T shaped tool to push the repair material through.

2. Rubber plug method. This uses a round rubber plug that has a "head". The plug is inserted into a gun shaped tool which has a hollow tip. The tip is pushed through the puncture and the tool squeezes the "head" out. The tool is withdrawn and this leaves the plug in place.

3. Interior patching. The tire is removed from the rim and the inside surface is prepared by light grinding. Some rubber cement is applied and a vulcanising patch is adhered. The area is sometimes heated to completed the curing process.

Needless to say the interior patching is the best as high speed cruising seals the area better compared to the 1st and 2nd methods which may leak due to centrifugal forces.

Cheers

Dr yky... of course i remember you. First 7 series oil change at UM2. So far your car is still the fastest coming down the hoist. Hmm funny that you get no throttle response improvement. There is another member in the forum that used the plugs in his 730. Well continue to monitor your car and let us know.

Thanks

[sszone]

Originally Posted by yky

My friend's E90 is shod with run flats all round.
PML advises against doing patching if one of the tyres get punctured, but to replace the tyre...almost $400 per tyre!!! Quite expensive for simple nail / sharps injuries.
What is the general opinion? Do a $10 patch repair job or go for a $400 replacement tyre?

the only question i have here is.....$400 for a tyre? so ex meh? can go to those tyre shops like Binter, i think can get a better tyre for 400 bucks at this places plus free alightment and stuff

[totoseow]

i had a run flat puncture in sepang. thick big fat nail went thru the middle of my front left. warning came on...i slowed down from the 1.1km stretch at more than 175kmh to 50kmh b4 turn one...n cruised the whole 4.5km back....when i got out..i hear a loud hissing sound...with no options but to drive to nearest town to patch...as i din carry a spare.

5myr patch job...n i went back to do a sprint run. finally...left sepang n flew back in 2.5 hours hitting 245kmh. continued to drive for another 1 mth...on those tires no problem..no more warnings no top up nothing.

i say these patches r very effective...IF the puncture is right in the middle. the RFs are strong at the side wall. if u rip the sides that is another story...otherwise i say patch it if its a nail...n life goes on..even at 245kmh..

[yky]

Yes, I believe that some ( myself included ) are not well informed as to what makes a tyre be classified as being 'runflat'...so don't know what to do if tyre puncture..take the official recommended path and change a new tyre. I am now slightly wiser. Thanks man. i will tell my friend that patching is the way to go for simple nails and screw injuries.

Rodney, I suppose my car is heavy lah or maybe my butt not sensitive enuff. Its ok. I am already very happy with the new found smoothness / quietness and 'softness' of the gearchanges and engine already.

[apache]

Originally Posted by totoseow

i had a run flat puncture in sepang. thick big fat nail went thru the middle of my front left. warning came on...i slowed down from the 1.1km stretch at more than 175kmh to 50kmh b4 turn one...n cruised the whole 4.5km back....when i got out..i hear a loud hissing sound...with no options but to drive to nearest town to patch...as i din carry a spare.

5myr patch job...n i went back to do a sprint run. finally...left sepang n flew back in 2.5 hours hitting 245kmh. continued to drive for another 1 mth...on those tires no problem..no more warnings no top up nothing.

i say these patches r very effective...IF the puncture is right in the middle. the RFs are strong at the side wall. if u rip the sides that is another story...otherwise i say patch it if its a nail...n life goes on..even at 245kmh..

Thanks a lot bro Totoseow !
I was also told by PML officially to change the tire whenever it is punctured. However, the sales associates did hinted to me that I can repair it if it is nail punctured. So, your experience provided the living proof that we can repair the tyre.