Some New Run Flat Information
06-29-2006, 06:02 AM
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I had an interesting chat with a technical rep. from Bridgestone.
He mentioned the following:-
RFT technology is no good for poor road surfaces. The side wall as the RF re-inforcing allowing very little sidewall flex. If you hit a pot hole, area of the road that has been dug up with sharp edges et. etc. the area just after the tread but before the reinforcing takes a lot of strain and can be damaged causing bulging. This has happened to me twice in 2 months. Non RFT tyres have alot more flex and are able to absorb the hit much better.
Bmw asked them and other manufacturers to drive the car with all 4 tyres totally empty. Bridgestone put on 4 new RFT's and drove 400km's (240 miles) and found that after close internal inspection the tyres will still in very good condition and ok for inflation and continued use.
However they also found that if the new tyres were first inflated to allow the side walls to stretch, then totally deflated and driven that the disatnce was decreased to 200km with small signs of damage.
After a slow or fast puncture the main reason for not allowing repairs is more that when removing the tyre from the rim the tyre shop can damage the side wall re-inforcing if they are not careful. It's not so much that the side walls can be damaged if the car is driven with a flat providing the distance and speed are minimal.
I am tired of having to replace bulged tyres so as soon as all my tyres need replacing I will be going for non RFT tyres.
Streak
He mentioned the following:-
RFT technology is no good for poor road surfaces. The side wall as the RF re-inforcing allowing very little sidewall flex. If you hit a pot hole, area of the road that has been dug up with sharp edges et. etc. the area just after the tread but before the reinforcing takes a lot of strain and can be damaged causing bulging. This has happened to me twice in 2 months. Non RFT tyres have alot more flex and are able to absorb the hit much better.
Bmw asked them and other manufacturers to drive the car with all 4 tyres totally empty. Bridgestone put on 4 new RFT's and drove 400km's (240 miles) and found that after close internal inspection the tyres will still in very good condition and ok for inflation and continued use.
However they also found that if the new tyres were first inflated to allow the side walls to stretch, then totally deflated and driven that the disatnce was decreased to 200km with small signs of damage.
After a slow or fast puncture the main reason for not allowing repairs is more that when removing the tyre from the rim the tyre shop can damage the side wall re-inforcing if they are not careful. It's not so much that the side walls can be damaged if the car is driven with a flat providing the distance and speed are minimal.
I am tired of having to replace bulged tyres so as soon as all my tyres need replacing I will be going for non RFT tyres.
Streak
06-29-2006, 01:47 PM
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Originally Posted by streak' post='305059' date='Jun 29 2006, 05:02 PM
RFT technology is no good for poor road surfaces. The side wall as the RF re-inforcing allowing very little sidewall flex. If you hit a pot hole, area of the road that has been dug up with sharp edges et. etc. the area just after the tread but before the reinforcing takes a lot of strain and can be damaged causing bulging.
Also note that the RF's weigh about + 50 %! :thumbsdown:
A Finnish carmagazine did a test on RF winter wheels.
They did hold on for some 300 + km's as empty.
Those who care, get RF's, but otherwise - forget about the RF's. :thumbsdown: :thumbsdown:
06-29-2006, 01:59 PM
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I just replaced my front passenger side Dunlop Runflat last week because of a bulge. BMW would not cover it under warrenty and said I must have hit a pothole (which I don't recall).
I almost replaced all four tires and got bigger wheels, but in the last minute I decided to just put another RF on and wait for all four tires to need replacing before changing to non-RF's with bigger wheels.
I almost replaced all four tires and got bigger wheels, but in the last minute I decided to just put another RF on and wait for all four tires to need replacing before changing to non-RF's with bigger wheels.
06-29-2006, 11:20 PM
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finally getting rid of my garbage RF's this next week, getting Toyo T1-R's so excited, going with a 245/40/18 Front and 255/35/18 rear. Can't wait.
06-30-2006, 12:13 AM
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Originally Posted by 530i SMG' post='305370' date='Jun 30 2006, 12:20 AM
finally getting rid of my garbage RF's this next week, getting Toyo T1-R's so excited, going with a 245/40/18 Front and 255/35/18 rear. Can't wait.
06-30-2006, 12:16 AM
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Originally Posted by rodybmw' post='305222' date='Jun 29 2006, 02:59 PM
I just replaced my front passenger side Dunlop Runflat last week because of a bulge. BMW would not cover it under warrenty and said I must have hit a pothole (which I don't recall).
I almost replaced all four tires and got bigger wheels, but in the last minute I decided to just put another RF on and wait for all four tires to need replacing before changing to non-RF's with bigger wheels.
I almost replaced all four tires and got bigger wheels, but in the last minute I decided to just put another RF on and wait for all four tires to need replacing before changing to non-RF's with bigger wheels.
06-30-2006, 04:01 AM
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Originally Posted by streak' post='305059' date='Jun 29 2006, 05:02 PM
I had an interesting chat with a technical rep. from Bridgestone.
He mentioned the following:-
RFT technology is no good for poor road surfaces. The side wall as the RF re-inforcing allowing very little sidewall flex. If you hit a pot hole, area of the road that has been dug up with sharp edges et. etc. the area just after the tread but before the reinforcing takes a lot of strain and can be damaged causing bulging. This has happened to me twice in 2 months. Non RFT tyres have alot more flex and are able to absorb the hit much better.
Bmw asked them and other manufacturers to drive the car with all 4 tyres totally empty. Bridgestone put on 4 new RFT's and drove 400km's (240 miles) and found that after close internal inspection the tyres will still in very good condition and ok for inflation and continued use.
However they also found that if the new tyres were first inflated to allow the side walls to stretch, then totally deflated and driven that the disatnce was decreased to 200km with small signs of damage.
After a slow or fast puncture the main reason for not allowing repairs is more that when removing the tyre from the rim the tyre shop can damage the side wall re-inforcing if they are not careful. It's not so much that the side walls can be damaged if the car is driven with a flat providing the distance and speed are minimal.
I am tired of having to replace bulged tyres so as soon as all my tyres need replacing I will be going for non RFT tyres.
Streak
He mentioned the following:-
RFT technology is no good for poor road surfaces. The side wall as the RF re-inforcing allowing very little sidewall flex. If you hit a pot hole, area of the road that has been dug up with sharp edges et. etc. the area just after the tread but before the reinforcing takes a lot of strain and can be damaged causing bulging. This has happened to me twice in 2 months. Non RFT tyres have alot more flex and are able to absorb the hit much better.
Bmw asked them and other manufacturers to drive the car with all 4 tyres totally empty. Bridgestone put on 4 new RFT's and drove 400km's (240 miles) and found that after close internal inspection the tyres will still in very good condition and ok for inflation and continued use.
However they also found that if the new tyres were first inflated to allow the side walls to stretch, then totally deflated and driven that the disatnce was decreased to 200km with small signs of damage.
After a slow or fast puncture the main reason for not allowing repairs is more that when removing the tyre from the rim the tyre shop can damage the side wall re-inforcing if they are not careful. It's not so much that the side walls can be damaged if the car is driven with a flat providing the distance and speed are minimal.
I am tired of having to replace bulged tyres so as soon as all my tyres need replacing I will be going for non RFT tyres.
Streak
06-30-2006, 04:12 AM
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However, on our wonderful, pot hole free Florida roads the RFs are great. Now at 26000 miles, with plenty tread left and still quiet and grippy. No complaints here. But again I think it has to do with the roads. Bridgestone Protenzas
06-30-2006, 08:36 AM
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I will give a report on how is goes.
I will give a report on how is goes.