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unusual question about run flats
- Thread starter wildbill
- Start date
it does in the ukaquazi said:i thought the flat tyre sensor worked off the abs and not a TPM?
In the US, you'd bugger the TPM, but Gannet's right, in the UK it works off ABS. If that's true down your way, go for it, but the whole idea of run-flat is to not have to use the tire goo. I got a small puncture in my tire-slow leak. Drove it 25 miles home and had it repaired the next day (off the tire patch, not a plug so they could inspect the inside of the tire).
Aside the pressure sensor that may or may not be an issue depending on which system is fitted, then an interesting question. The idea of course is a cumulative mileage of 50 miles at 50mph mas as over time the side wall deteriorates and renders the tyre useless.
If you didn't drive it and the puncture is in a repairable point and the garage is prepared to clean out the tyre and rim, then I see no reason why it would not save the tyre
If you didn't drive it and the puncture is in a repairable point and the garage is prepared to clean out the tyre and rim, then I see no reason why it would not save the tyre
cj10jeeper said:Aside the pressure sensor that may or may not be an issue depending on which system is fitted, then an interesting question. The idea of course is a cumulative mileage of 50 miles at 50mph mas as over time the side wall deteriorates and renders the tyre useless.
If you didn't drive it and the puncture is in a repairable point and the garage is prepared to clean out the tyre and rim, then I see no reason why it would not save the tyre
Correct, if those guidelines are followed, tyre can be fitted back on and be just as reliable.
wildbill said:just wondering if you were unlucky enough to score a puncture on run-flats and immediately filled it with tyre foam - would that move save the life of the run -flat tyre???
i ran my run flats once over a 130km trip going home by filling up the tires everytime i saw a gas station. on the first station pressure was 14 ran it about 5kms, stopped, re gassed, ran it again.
the next day i went to the service shop, they did not see any damage, just a small puncture and patched it. drove with the tire for another 10000 kms and changed it since the tread is already at the time to change indicator.
Z4rro said:Just an opinion, but why on earth would you repair a puncture in a tyre that's on a pretty powerful sports car? I think I value life a bit too much to do it. :thumbsdown:
I don't know enough about tyre technolgy to say, but my instinct is to agree, similarly low tread or cheap tyres. If a repaired tyre failed and you had an accident, would an insurance company try to reduce its liability?
Z4rro said:Just an opinion, but why on earth would you repair a puncture in a tyre that's on a pretty powerful sports car? I think I value life a bit too much to do it. :thumbsdown:
I think the answer to all this is degree and location. A small nail hole in the tread can be easily repaired with no detriment to the tyre or safety whatsoever. A puncture in the sidewall renders the tyre useless and dangerous, but could no doubt be repaired to some degree if you found someone willing.
As for references to driving with it deflated then using again - that's real dangerous. When it runs on the sidewall it wears it out really quick, hence the 50mile limit. If reused the tyre is really weak, but of course may well hold air and seem OK. I picked up some alloys with a damaged rft and it had handsfull of rubber beads when I took the 'scrap' tyre off to refurb the rim, where the inside had cracked and split with prior owner driving it deflated. :thumbsdown:
Personally I'd not repair tyres on a high performance car at all, but that's really down to an individuals judgement and value system.
As CJ said, if there had been any damage to the sidewalls, I would have gotten a new tire for that wheel. Slow leaks from a small nail hole in the tread are another matter. The repair would have to be an off-wheel one so the inside can be inspected thoroughly. I drove it gingerly for a few days to make sure there were no leaks.
Haven't seen this mentioned yet ........ but I carry a small compressor in the boot that runs off the 12v lighter socket. Think I got it from Halfords.
I used it for years on my range rover, pumping up the air suspension (was manually over ridden) and it works really well.
With the average puncture on the road, I'd keep inflating it till I got to a repair station.
Not at all sure that repairing a RFT after its actually been "run flat" is a good idea.
I used it for years on my range rover, pumping up the air suspension (was manually over ridden) and it works really well.
With the average puncture on the road, I'd keep inflating it till I got to a repair station.
Not at all sure that repairing a RFT after its actually been "run flat" is a good idea.
The owner manual states if the tyre is fully deflated, the car can still travel 155 miles at max. 50 mph with driver only.
My car had a puncture on Tuesday, the bolt was found on 3/4 tread area. BMW dealer checked for any structural damage to the sidewall of the tyre, and said it was safe to repair it. Because I only travelled about 40 miles on my own after the warning light came up, and the tyre was not fully deflated (only slow puncture). So I think the dealer was right to fix my tyre.
My car had a puncture on Tuesday, the bolt was found on 3/4 tread area. BMW dealer checked for any structural damage to the sidewall of the tyre, and said it was safe to repair it. Because I only travelled about 40 miles on my own after the warning light came up, and the tyre was not fully deflated (only slow puncture). So I think the dealer was right to fix my tyre.
When I bought my car, foolishly, I didn't check the pressures. You wouldn't expect to from a trader.
The next day after having done about 100 miles of various fast ish driving my warning thing came on. Stopped and checked tyres. 9psi, 12psi, 15psi and 20psi or something similar. Nice!
So I refilled and they lasted another few months till replaced.
When I took them off they looked fine inside.
I think you could drive on them flat (ish) for about 1000 miles at reasonable speeds and be ok in most cases. The low numbers are just BMW covering their arses I think?!
Best off without anyway, they cause more problems than they solve imo! Cost more, and if they slow leak they can be run low/flat for a LOT longer than you think (on the UK system they can go flat over weeks and you never know).
Dave
The next day after having done about 100 miles of various fast ish driving my warning thing came on. Stopped and checked tyres. 9psi, 12psi, 15psi and 20psi or something similar. Nice!
So I refilled and they lasted another few months till replaced.
When I took them off they looked fine inside.
I think you could drive on them flat (ish) for about 1000 miles at reasonable speeds and be ok in most cases. The low numbers are just BMW covering their arses I think?!
Best off without anyway, they cause more problems than they solve imo! Cost more, and if they slow leak they can be run low/flat for a LOT longer than you think (on the UK system they can go flat over weeks and you never know).
Dave
I did some research on the internet after my Zed had a rear tyre puncture this week.
From Bridgestone Europe
Q: What is the threshold pressure below which a tyre is deemed to have been Runflat?
A: The international standard ISO 16992:2006 states that below 70 kPa (10.15 psi) an RFT tyre is deemed to have been run flat.
Q: Can I repair a punctured Bridgestone Runflat tyre?
A: Bridgestone RFT tyres marked "Do Not Repair" must be replaced if punctured, and cannot be repaired.
I had the tyre pressure set at 43.5 psi before it had the slow puncture, and was driving less than 50 miles at max. 50 mph to the dealer. So I think my repaired RF tyre (3rd generation) is still safe to use.
From Bridgestone Europe
Q: What is the threshold pressure below which a tyre is deemed to have been Runflat?
A: The international standard ISO 16992:2006 states that below 70 kPa (10.15 psi) an RFT tyre is deemed to have been run flat.
Q: Can I repair a punctured Bridgestone Runflat tyre?
A: Bridgestone RFT tyres marked "Do Not Repair" must be replaced if punctured, and cannot be repaired.
I had the tyre pressure set at 43.5 psi before it had the slow puncture, and was driving less than 50 miles at max. 50 mph to the dealer. So I think my repaired RF tyre (3rd generation) is still safe to use.