是可以，但是如果沒氣跑了很久就不行了

Feature: Can you repair run-flat tires?

By Paul Williams; photos courtesy Bridgestone

Run-flat tires are becoming more common as original equipment on new vehicles. They save space, weight, and are designed to increase safety. But owners of vehicles with run-flat tires are asking, “In the event of a puncture, can a run-flat tire be repaired?”

The answers are “yes,” “no,” and “maybe,” depending on who you ask. For the definitive answer, read on.

The use of Bridgestone run-flat tires on the BMW 3 Series was the first large-scale, original equipment (OE) application of these tires in the North American market. At the time, there was a directive from tire-supplier Bridgestone to retailers not to repair damaged run-flat tires, instead sending them back to headquarters for inspection. Mark Kuykendall, Bridgestone’s Engineering Manager for Bridgestone Light Vehicle and Truck Tires, explained, “Initially, we didn’t want the tires repaired because we didn’t have sufficient field data.”

In other words, although the tires had been tested in controlled situations, there wasn’t data from thousands of applications over time upon which to base general conclusions concerning the effectiveness of run-flat tire repairs. Being cautious, Bridgestone requested that retailers fit a new tire, and send damaged/worn tires back for inspection, ultimately determining that the tires can safely be repaired.

Consequently, Bridgestone issued a Repair Procedure in May, 2005 for run-flat tires.

The procedure specifies that the inside of the tire must be professionally inspected (which means the tire must be off the wheel), and if it passes, then a patch/plug combination will effect a satisfactory repair.

This is confirmed by local Ottawa tire retailer, Fri*****y Tire. Manager Francis Peori states that his shop has successfully repaired many run-flat tires using the patch/plug method. “No problem at all,” says Mr. Peori, who has consulted with representatives of the major brands that make run-flat tires, including Bridgestone.

As an aside, it’s possible that the initial directive by Bridgestone not to repair its run-flat tires has circulated more widely than expected, leading to the mistaken conclusion that run-flat tires are not to be repaired, period. This conclusion is obsolete.

In some situations, however the tire won’t pass inspection and can’t be repaired. Contributing factors would be excessive heat compromising the structure of the tire (run-flats do run hotter than conventional tires), excessive load, and/or running the tire with no pressure for too long at excessive speeds.

How long is too long, and what’s too fast? The International Standards Organization (ISO) indicates that for a tire to be called “run-flat” it must be able to run at 80 km/h for 80 kilometres with no pressure. Beyond these minimums, your chances of successfully repairing the tire decrease.

Another indication of whether the tire can be repaired is via the car’s Tire Pressure Monitoring System (TPMS), which is part of the run-flat specification.

The TPMS system is informed by sensors in the wheels, and typically generates a two-stage warning consisting of a visual (light) and audible phase. When the light comes on, Mr. Kuykendall suggests, it means the pressure is low; when the audible warning sounds, indicating that the pressure is minimal or gone; you effectively have a “flat” tire (although it won’t look flat, as the sidewall provides support).

In both cases, adding air to the tire may help. If the tire pressure is low, adding air may temporarily solve the problem; if the pressure is gone, the tire may still hold some air for a while, which may extend the time you have to get to a garage or retailer. Carrying a small foot pump or 12-volt compressor in the car is a good idea for owners of vehicles with run-flat tires, therefore, especially if you drive in remote areas.

Mr. Kuykendall cautions against the use of aerosol products to inflate and/or repair a tire. Aerosol products are “90-percent water,” he says. Put that in your tire and you’ll ruin your TPMS wheel sensor (which may cost as much as a new tire to replace).

As far as repair sealants are concerned, Mr. Kuykendall’s opinion is that once a sealant goes in, the tire is unrepairable. However, temporary repair products such as Slime Spair are recommended by their manufacturers as TPMS-friendly, and plug/patch repairable.

In conclusion, the answer to the question, “Can run-flat tires be repaired?” is “Yes”. A run-flat tire can be repaired as long as it passes inspection by an authorized retailer who uses a plug/patch method (following the manufacturer’s recommended repair procedure). Opinions to the contrary are out of date.

Note that no tire, run-flat or conventional, can be repaired if the sidewall is perforated.

Other run-flat tire questions

Q: Can I mount a non run-flat (conventional) tires on a run-flat rim?

A: The rims for run-flat tires are different than those for conventional tires. You can use a conventional tire on a run-flat rim, but the TPMS will no longer work.

Q: Can I mount run-flat tires on a non run-flat (conventional) rim?

A: You cannot mount a run-flat tire on a conventional rim. The rim is different.

Q: Can I change my wheels and tires to non-run flat?

A: You can choose to buy a set of conventional rims and conventional tires and replace your run-flat rim/tires of the appropriate size. However, your TPMS will no longer work, and you’ll be without a spare tire, jack and lug wrench. You may also alter the handling behaviour or your vehicle.

Q: What about carrying a space-saver spare?

A: You could do this. You’d also need a jack, lug wrench, and a secure place to store the wheel/tire. Chances are you’d be better off heading to a repair facility and fixing your tire if required.

Q: In the event of a puncture, what about towing/flat-bedding?

A: Vehicles under warranty often include road-side assistance, which means that towing/flat-bedding is an option. However, the run-flat tire really is designed to get you to a tire retailer or service facility without having to use these resources. If you don’t have Navigation in your vehicle, the least expensive portable GPS unit will point you to the nearest service center or dealer.

所有跟帖： 

• 我車上有個jump starter/compressor.發現胎壓不夠後加足了氣才開到修車鋪。 -其樂無窮- ♂ (74 bytes) () 04/03/2014 postreply 09:34:16

• 那應該沒有問題 -soccer88- ♂ (0 bytes) () 04/03/2014 postreply 15:59:57