Are Firestone Runflats Really "Run Flats?"
11-22-2009, 11:53 AM
#1
Drifting
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St. Jude Donor '09 & '11
Are Firestone Runflats Really "Run Flats?"
I recently replaced the original GY runflats on my 05 C6 with Firestone wide oval runflats at 14,000 miles. I have about 1000 miles on the Firestones - no complaints - they are smooth, quiet and I can't notice any difference in the handling characteristics. However, yesterday I pulled out of the driveway and heard a thump thump sound immediately. I didn't even get up to 20 mph. Tire indicator said I had a left rear flat so I went back to my garage. Sure enough it was flat (O air pressure). This experience makes me think the Firestone runflats might not be very driveable at 50 mph when flat. Anyone had any experience with running on flat Firestones yet? Now to find a place to get it fixed!
11-22-2009, 12:57 PM
#3
Moderator
I hope you got Road Hazard warranty when you bought your Firestone's. The wide ovals for the Corvette are marked on the sidewalls "Do not repair". Per the Firestone policy, these tires are not repairable and must be replaced:
WHAT IS THE REPAIRABLE AREA OF AN RFT (RUN FLAT) TIRE?
No tire, regardless of its design or quality, is indestructible. RFT tires can be ultimately rendered unusable due to a puncture or other road hazard as well as from improper run-flat or low pressure operation. Some punctures may be repaired under certain circumstances, with restrictions and subject to prescribed procedures.
When driven flat or with low pressure, factors affecting reparability include vehicle speed, load, handling and maneuvering; the amount of inflation pressure lost; and ambient temperature. In any situation, the extent and location of direct damage from a puncturing object or other road hazard are also critical factors.
RFT tires are not repairable in any of the following situations:
If the tire is described as, "Do Not Repair" on the sidewall.
If the tire was operated with inflation pressure less than 15 psi (100 kPa).
Abrasion or other damage is present on the exterior tread, sidewall or bead areas.
Abrasion, wrinkling, or separation is present on the tire interior.
Any condition or damage is present that disqualifies repair of a conventional tire.
Run-Flat Certified Retailers will fully inspect your tire, inside and out, to determine if the tire can be repaired. Tire damage is not always visible from the outside and the tire must be removed from the wheel for a complete inspection.
No tire, regardless of its design or quality, is indestructible. RFT tires can be ultimately rendered unusable due to a puncture or other road hazard as well as from improper run-flat or low pressure operation. Some punctures may be repaired under certain circumstances, with restrictions and subject to prescribed procedures.
When driven flat or with low pressure, factors affecting reparability include vehicle speed, load, handling and maneuvering; the amount of inflation pressure lost; and ambient temperature. In any situation, the extent and location of direct damage from a puncturing object or other road hazard are also critical factors.
RFT tires are not repairable in any of the following situations:
If the tire is described as, "Do Not Repair" on the sidewall.
If the tire was operated with inflation pressure less than 15 psi (100 kPa).
Abrasion or other damage is present on the exterior tread, sidewall or bead areas.
Abrasion, wrinkling, or separation is present on the tire interior.
Any condition or damage is present that disqualifies repair of a conventional tire.
Run-Flat Certified Retailers will fully inspect your tire, inside and out, to determine if the tire can be repaired. Tire damage is not always visible from the outside and the tire must be removed from the wheel for a complete inspection.
11-22-2009, 02:40 PM
#5
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I recently replaced the original GY runflats on my 05 C6 with Firestone wide oval runflats at 14,000 miles. I have about 1000 miles on the Firestones - no complaints - they are smooth, quiet and I can't notice any difference in the handling characteristics. However, yesterday I pulled out of the driveway and heard a thump thump sound immediately. I didn't even get up to 20 mph. Tire indicator said I had a left rear flat so I went back to my garage. Sure enough it was flat (O air pressure). This experience makes me think the Firestone runflats might not be very driveable at 50 mph when flat. Anyone had any experience with running on flat Firestones yet? Now to find a place to get it fixed!
How ever slight that might be considering it's a run flat tire, that would cause the thumping.
There wouldn't be a flat spot to cause thumping, if the tire lost air while the car was being driven, or didn't sit around a while first.
11-22-2009, 04:32 PM
#6
Drifting
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St. Jude Donor '09 & '11
It has a screw in it. Thankfully I did purchase Road Hazard insurance for them. And I think I agree the thumping may have been because the car was sitting for a while with a flat (I didn't know it). Thanks for the responses guys.
11-22-2009, 04:33 PM
#7
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C7 of the Year - Unmodified Finalist 2021
Mine say RFT on them so if they are classifed as run-flat I would assume that there are tests that would have to be met to be legally allowed to advertise the tires as such.
11-22-2009, 06:22 PM
#8
Race Director
While they are run flats, they cannot be legally repaired thanks to Firestone's problem in the past. That is a big reason why Michelin is getting my money when the time comes.
11-22-2009, 07:29 PM
#9
Melting Slicks
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St. Jude Donor '06-'07-'10, '15. '22-'23
I just looked at mine and I don't see any "Do Not Repair" warning, that must be something new. This is my second set of Firestones. I did get a bolt through one a while ago but it went into the sidewall so repair was a non-issue anyway. I didn't know they were no longer repairing punctures in the tread! 
11-23-2009, 06:57 AM
#10
Le Mans Master
I was not aware of the "Do not repair" warning and it isn't clear to me that is what is meant by the warning. It is part of the safety info on the sidewall outside just below the treadwear etc. ratings and to the right of the rotation arrow. It says that serious injury may occur if... and proceeds to list things like driving faster than 55mph or more than 50 miles but then says the injury might be caused by tire damage due to driving when flat followed by do not repair and do not reinflate. Does that mean NEVER repair or just do not repair if there is damage?
Zymurgy's quoting of Firestone's policy would help answer this if it didn't also say the tire was unrepairable if operated below 15psi. Why bother with all those other clauses if it is unrepairable if ever operated below 15psi? It appears that Firestone's lawyers were given a little too much freedom.
Zymurgy's quoting of Firestone's policy would help answer this if it didn't also say the tire was unrepairable if operated below 15psi. Why bother with all those other clauses if it is unrepairable if ever operated below 15psi? It appears that Firestone's lawyers were given a little too much freedom.
11-23-2009, 09:15 AM
#11
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I was not aware of the "Do not repair" warning and it isn't clear to me that is what is meant by the warning. It is part of the safety info on the sidewall outside just below the treadwear etc. ratings and to the right of the rotation arrow. It says that serious injury may occur if... and proceeds to list things like driving faster than 55mph or more than 50 miles but then says the injury might be caused by tire damage due to driving when flat followed by do not repair and do not reinflate. Does that mean NEVER repair or just do not repair if there is damage?
Zymurgy's quoting of Firestone's policy would help answer this if it didn't also say the tire was unrepairable if operated below 15psi. Why bother with all those other clauses if it is unrepairable if ever operated below 15psi? It appears that Firestone's lawyers were given a little too much freedom.
Zymurgy's quoting of Firestone's policy would help answer this if it didn't also say the tire was unrepairable if operated below 15psi. Why bother with all those other clauses if it is unrepairable if ever operated below 15psi? It appears that Firestone's lawyers were given a little too much freedom.
11-23-2009, 10:03 AM
#14
Drifting
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St. Jude Donor '09 & '11
Well, I just checked with the local Firestone dealer. They will not repair their runflats because they say it would compromise the speed rating. Guess you need to be sure to buy road hazard protection if you buy Firestones.
11-23-2009, 12:44 PM
#15
Pro
Sounds like Firestone is playing games.
11-23-2009, 02:24 PM
#17
Moderator
Goodyear run flats will maintain their speed rating if repaired properly:
Goodyear Speed-Rated Tire Repair Limits
II. DETAILED POLICY - Puncture Repair of Goodyear Speed-Rated Tires
The puncture must be confined to the tread area only.
(See "Repair Area", item III-B).
Restrictions on the number and size of repairs must be followed.
(See "Puncture Repair Limits" table, item III-C).
A detailed repair procedure must be followed.
(See "Repair Procedure", item III-E).
A Goodyear speed-rated new tire repaired in strict accordance with items II-A, B & C, will retain its speed rating.
III. REPAIR PROCEDURE FOR SPEED-RATED TIRES
GENERAL
The objective of the puncture repair is to seal the tire against loss of inflation pressure and to prevent damage to the carcass from moisture. In all puncture repairs approved by Goodyear, the hole must be filled with a plug, and a patch covering the hole must be applied according to repair material manufacturer instructions to the inside of the tire. Never repair tires which are worn below 2/32" tread depth.
NOTE: No tire is to be repaired without first being removed from the rim.
REPAIR AREA
Repairing is limited to the tread area only within the outside grooves. No repairs are allowed in the tread area beyond the outside grooves or sidewall.
PUNCTURE REPAIR LIMITS
TIRE SPEED...............MAX. NUMBER...........MAX REPAIR
(SPEED SYMBOL)................................. ....DIAMETER
130 mph and over ...........1......................1/4 in. (6mm)
(H, V, Z)
II. DETAILED POLICY - Puncture Repair of Goodyear Speed-Rated Tires
The puncture must be confined to the tread area only.
(See "Repair Area", item III-B).
Restrictions on the number and size of repairs must be followed.
(See "Puncture Repair Limits" table, item III-C).
A detailed repair procedure must be followed.
(See "Repair Procedure", item III-E).
A Goodyear speed-rated new tire repaired in strict accordance with items II-A, B & C, will retain its speed rating.
III. REPAIR PROCEDURE FOR SPEED-RATED TIRES
GENERAL
The objective of the puncture repair is to seal the tire against loss of inflation pressure and to prevent damage to the carcass from moisture. In all puncture repairs approved by Goodyear, the hole must be filled with a plug, and a patch covering the hole must be applied according to repair material manufacturer instructions to the inside of the tire. Never repair tires which are worn below 2/32" tread depth.
NOTE: No tire is to be repaired without first being removed from the rim.
REPAIR AREA
Repairing is limited to the tread area only within the outside grooves. No repairs are allowed in the tread area beyond the outside grooves or sidewall.
PUNCTURE REPAIR LIMITS
TIRE SPEED...............MAX. NUMBER...........MAX REPAIR
(SPEED SYMBOL)................................. ....DIAMETER
130 mph and over ...........1......................1/4 in. (6mm)
(H, V, Z)
Goodyear Run Flat Repair Procedure
REPAIR PROCEDURE
1. CAREFULLY REMOVE THE TIRE COMPLETELY FROM THE RIM.
2. Locate the puncture on the inside of the tire and circle with crayon.
3. Remove puncturing object if it is still in the tire.
4. Carefully inspect tire on a good tire spreader, with ample light, which will show any cracks, breaks, punctures, damaged or broken beads.
5. Check liner for cuts, cracks, or holes which may cause the tubeless liner to lose air.
6. Check the injury with an inspection awl:
(a)Determine size and angle of injury.
(b)Check for ply or belt separation.
7. Reject any tire that has separation, loose cords, damaged bead(s), or any other non-repairable injury.
8. If the hole is simple and round, steps 9 through 17 of the puncture repair procedure will be successful.
NOTE: If the hole shows evidence of fabric splitting, such an injury cannot be properly repaired using this puncture repair procedure. Such an injury must be skived out and repaired as a section (reinforced) repair, which will maintain the serviceability of the tire, but will invalidate the tire's speed rating. If a section repair is necessary, the customer must be advised, before the repair is made, that the tire will lose its speed rating, and must not exceed operation at normal highway speeds.
9. Use a pre-buff cleaner and a scraper to remove contaminants from the liner in the area to be buffed around the injury.
10. Use a 7/32"carbide cutter for 1/4" repairs to clean out the puncture.
(a)Make sure that the drill follows the direction of the puncturing object.
(b)Always drill from inside to outside of tire.
11. Using chemical vulcanizing cement, lightly coat at least 1/2 of the tapered end of the repair plug. Install the plug in the prepared puncture according to the manufacturer's instructions. Trim the liner side of the plug slightly higher than the surface of the liner without stretching the plug.
12. Center the patch (or patch template) over the injury without removing the backing. Adhere to patch or template instructions, as to positioning as related to bead location. Mark around the outside edge of the patch, approximately 1/4" larger than the patch.
13. Buff the liner and plug at the puncture location. The buffed area should be slightly larger than the patch. The buffed surface should be finely grained (RMA 1 or 2 texture) and even for proper bonding. Use care to prevent burning the rubber with the buffing tool. Do not buff through the liner. Do not buff into the marking crayon.
14. Clean the buffing dust from the tire using only a vacuum or brush. Do not use gasoline or other petroleum solvents on the buffed area.
15. Coat the buffed liner surface and the patch with one evenly applied coat of chemical vulcanizing cement in accordance with the recommendations of the repair materials manufacturer. Allow the cement to dry thoroughly. Do not touch the cemented areas.
16. Install the patch with the beads of the tire in the relaxed position. Position the patch over the puncture according to the markings on the patch. Stitch the entire patch starting from the center, keeping the strokes close together to avoid trapping air under the patch.
17. Cut off the protruding end of the plug about 1/8" above the tread surface.
18. FINAL INSPECTION - The repair must seal the inner liner and fill the injury. After remounting and inflating check the repair, both beads and valve with a soap solution to assure a complete seal.
REPAIR PROCEDURE
1. CAREFULLY REMOVE THE TIRE COMPLETELY FROM THE RIM.
2. Locate the puncture on the inside of the tire and circle with crayon.
3. Remove puncturing object if it is still in the tire.
4. Carefully inspect tire on a good tire spreader, with ample light, which will show any cracks, breaks, punctures, damaged or broken beads.
5. Check liner for cuts, cracks, or holes which may cause the tubeless liner to lose air.
6. Check the injury with an inspection awl:
(a)Determine size and angle of injury.
(b)Check for ply or belt separation.
7. Reject any tire that has separation, loose cords, damaged bead(s), or any other non-repairable injury.
8. If the hole is simple and round, steps 9 through 17 of the puncture repair procedure will be successful.
NOTE: If the hole shows evidence of fabric splitting, such an injury cannot be properly repaired using this puncture repair procedure. Such an injury must be skived out and repaired as a section (reinforced) repair, which will maintain the serviceability of the tire, but will invalidate the tire's speed rating. If a section repair is necessary, the customer must be advised, before the repair is made, that the tire will lose its speed rating, and must not exceed operation at normal highway speeds.
9. Use a pre-buff cleaner and a scraper to remove contaminants from the liner in the area to be buffed around the injury.
10. Use a 7/32"carbide cutter for 1/4" repairs to clean out the puncture.
(a)Make sure that the drill follows the direction of the puncturing object.
(b)Always drill from inside to outside of tire.
11. Using chemical vulcanizing cement, lightly coat at least 1/2 of the tapered end of the repair plug. Install the plug in the prepared puncture according to the manufacturer's instructions. Trim the liner side of the plug slightly higher than the surface of the liner without stretching the plug.
12. Center the patch (or patch template) over the injury without removing the backing. Adhere to patch or template instructions, as to positioning as related to bead location. Mark around the outside edge of the patch, approximately 1/4" larger than the patch.
13. Buff the liner and plug at the puncture location. The buffed area should be slightly larger than the patch. The buffed surface should be finely grained (RMA 1 or 2 texture) and even for proper bonding. Use care to prevent burning the rubber with the buffing tool. Do not buff through the liner. Do not buff into the marking crayon.
14. Clean the buffing dust from the tire using only a vacuum or brush. Do not use gasoline or other petroleum solvents on the buffed area.
15. Coat the buffed liner surface and the patch with one evenly applied coat of chemical vulcanizing cement in accordance with the recommendations of the repair materials manufacturer. Allow the cement to dry thoroughly. Do not touch the cemented areas.
16. Install the patch with the beads of the tire in the relaxed position. Position the patch over the puncture according to the markings on the patch. Stitch the entire patch starting from the center, keeping the strokes close together to avoid trapping air under the patch.
17. Cut off the protruding end of the plug about 1/8" above the tread surface.
18. FINAL INSPECTION - The repair must seal the inner liner and fill the injury. After remounting and inflating check the repair, both beads and valve with a soap solution to assure a complete seal.
11-23-2009, 03:16 PM
#18
Team Owner
Goodyear run flats will maintain their speed rating if repaired properly:
11-23-2009, 08:46 PM
#19
Moderator
Yes, I agree. If you read the information I posted, the limit is 1 repair of a maximum of 1/4". And it has to be a patch and plug.
