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CBR600FV

Run-flat repairs?

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Question to the forum regarding legality of repairing a run-flat. I realise the risk of internal damage to the reinforced sidewalls in the event of running on low or no pressure but not happy to replace a tyre that only done 3k miles. I got home yesterday to a warning @ 33 psi. Overnight pressure had dropped to near enough zero so inflated to 40psi. Pressure is dropping quite quickly (10 psi in 90 mins) I am confident that there cannot be any internal sidewall damage so would be happy with an internal plug/patch.Out of interest, the tyre with zero pressure showed no signs of sidewall deformation even with the car weight, so sensors definitely required. 

Also, i always though that TPMS sensors only became active when the wheels were rolling so as to save the internal battery, but the BMW screen showed live readings as the tyre was inflated???

Thoughts??

N.S. Rear.jpg

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I've had a few RFT tyres repaired in the past however a lot of places won't do it as it's against their policy. 

 

Kwik fit and BMW won't go near them for example. 

 

They're covering the risk of the tyre being driven on while flat and then it could compromise the sidewalls so should be replaced in that case. 

 

If you know the car hasn't been driven while flat then you've got that peace of mind yourself, however I personally wouldn't do it if the car was sitting on the flat tyre overnight. 

 

I've only done this with a slow puncture highlighted by TPMS and never left long enough to go flat.

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I’ve had a couple of runflats repaired. Most big firms like ATS etc just refuse to do it, they never gave any reason regarding legality, just wouldn’t do it. I think some of them say you can never be sure it hasn’t been driven on flat, stupid thing to say if it’s only been you driving it, but maybe just covering them selfs. 
 

As said as long as you know it hasn’t be driven on flat & where you have the screw stuck in that picture it would be fine to have repaired, as long as you can find someone to do it....

 

 

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18 minutes ago, CBR600FV said:

Also, i always though that TPMS sensors only became active when the wheels were rolling so as to save the internal battery, but the BMW screen showed live readings as the tyre was inflated???


That is interesting, I was just wondering how long they stayed on / how long the batteries are likely to last.
Think I prefer then using wheel speed instead really, they still alarm very quickly, long before you have lost any significant amount of air. 

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1 hour ago, JDX-90 said:

I've had a few RFT tyres repaired in the past however a lot of places won't do it as it's against their policy. 

 

Kwik fit and BMW won't go near them for example. 

 

They're covering the risk of the tyre being driven on while flat and then it could compromise the sidewalls so should be replaced in that case. 

 

If you know the car hasn't been driven while flat then you've got that peace of mind yourself, however I personally wouldn't do it if the car was sitting on the flat tyre overnight. 

 

I've only done this with a slow puncture highlighted by TPMS and never left long enough to go flat.

Same here, use my local family-owned tyre place, they repair them no questions.  I've only had ones with slow punctures repaired though.

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2 hours ago, JDX-90 said:

If you know the car hasn't been driven while flat then you've got that peace of mind yourself, however I personally wouldn't do it if the car was sitting on the flat tyre overnight


I think there must be thousands of people who have come out in the morning to find a flat tyre and then taken it in for repair (I certainly have!). Mostly non-RoFs of course but a RoF can’t possibly be any less safe surely.

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55 minutes ago, Boba said:


I think there must be thousands of people who have come out in the morning to find a flat tyre and then taken it in for repair (I certainly have!). Mostly non-RoFs of course but a RoF can’t possibly be any less safe surely.

 

Yes I'm sure many people have.

 

The bigger issue is definitely driving on the sidewall while flat but if the weight of the car is on the sidewall with no air in the tyre for a prolonged period of time this can cause creases in the rubber.

 

It will come down to personal choice but I wouldn't be confident that the safety hasn't been compromised in that situation.

 

I'm sure there are experts out there which will have views on both sides but for me it won't be as structurally sound as it was before it was placed under that type of strain.

 

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59 minutes ago, Boba said:


I think there must be thousands of people who have come out in the morning to find a flat tyre and then taken it in for repair (I certainly have!). Mostly non-RoFs of course but a RoF can’t possibly be any less safe surely.


Each to their own but I wouldn’t have a problem with that either. A runflat is probably actually better than a non runflat in that instance as it hasn’t totally collapsed. 
 

Its the heat built up you get in the side walls (using runflats for their intended purpose) that really damages them. If you look inside one that has done a good few miles flat the sidewalls are all broken up, the slightly dangerous part being the outside of the side walls still looks fine...

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^ I do agree with above that it's probably less of an issue on run flats being flat overnight, as long as they haven't been driven on. 

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Morning Forum, Out of interest I took 2 piccies this morning, one is with the offending tyre with zero pressure, the other with 40 psi. Can anyone tell which is which? Just shows how little sidewall deformation there is with runflats. 

Runflat A.jpg

Runflat B.jpg

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20 minutes ago, CBR600FV said:

Morning Forum, Out of interest I took 2 piccies this morning, one is with the offending tyre with zero pressure, the other with 40 psi. Can anyone tell which is which? Just shows how little sidewall deformation there is with runflats. 

Runflat A.jpg

Runflat B.jpg

Same picture?

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They do look the same but that's the whole point of the run flats, they sit on the side wall and inflation won't effect that. 

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Pics were taken in the same position, I renamed them runflat A & runflat B for my reference. Piccy "info" tells me what time they were taken.

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Exact same marks on tyres and maker’s name etc. in exact same positions and identical lighter-coloured spots on the ground in the exact same relative position to the wheels. Leg-pull?

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No, absolutely not a leg pull, as I said taken 21 minutes apart, was just trying to show the negligible sidewall deformation with zero pressure. If the forum doesn't belive me then go & let your runflats down & witness for yourselves........:D

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Oh right, I misunderstood, I thought it was 2 different wheels no the same one just reinflated . Yes I agree that they do look the same with or without pressure which is what they should of course. Pretty reassuring as I keep mine on RoFs to guard against blow outs at speed.

Edited by Boba

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48 minutes ago, Boba said:

Oh right, I misunderstood, I thought it was 2 different wheels no the same one just reinflated . Yes I agree that they do look the same with or without pressure which is what they should of course. Pretty reassuring as I keep mine on RoFs to guard against blow outs at speed.

Same understanding.

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Yep and having had a tyre go from full pressure to 0 in about 10 seconds, I was very thankful I had run flats on!

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11 hours ago, Carrman2018 said:

Same picture?

 

FYI: Agreed, fat finger error, the images are identical when compared at a binary level.

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8 hours ago, DarkHorse said:

 

FYI: Agreed, fat finger error, the images are identical when compared at a binary level.

 

either it's a mistake or somehow, OP has managed to get

 

1. Identical lighting

2. Identical positioning of camera lens+subject

3. Taken 21 minutes apart but the water on the floor hasn't dried up even 1 iota

4. Pixel by pixel, the exact same image

 

I'm very sceptical about them being 2 separate photos. There may be two separate photos - but this is 1 image repeated twice by all accounts

 

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Apologies to the forum, Photo Editor has been sacked, New photos taken within the last hour or so. I was only trying to show how negligible the tyre wall deformation is with zero pressure compared with normal or higher pressure.

ROF a.jpg

ROF b.jpg

ROF c.jpg

ROF d.jpg

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Certain tyre manufacturers do endorse repairs of rft provided they have not been run on flat.

 

these are Michelin, Dunlop, Bridgestone and Goodyear.  Other manufacturers do not endorse repairing rfts.

 

I got my Michelin rft repaired by a local family run business, who confirmed they believed my story that the tyre had not been run on flat when they inspected the inside of the tyre.

 

Trick is finding a tyre fitter who will do the repair.

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Too much time on your hands there OP! :D

Nice watch! Tbf even alone another angle between the two photos dispels the 'it's the same photo' issue.

 

I've repaired run flats (which have not actually run flat) in the past without any issues. Local place will check if it's been compromised as much as possible but will patch up eventually anyway

 

 

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