The basics are the same as a bicycle puncture. Tube Tire Flat Tire Cases and Repair Methods and Precautions

Even if you are driving at the same pace as usual on the same road as usual, one day you will suddenly encounter a "flat tire. It is sometimes said that you are more likely to step on a nail because you are driving close to the roadside, but there are also times when foreign objects are lying around even in the middle of the lane, and to put it bluntly, it is an aspect of luck. Tube tires, which are common on spoked-wheel vehicles, have the weakness of easily losing all their air at once when you step on a nail, but they also have the advantage of being easy to fix if you have experience in bicycle puncture repair.

What are the main causes and patterns of tube tire punctures?

A screw is stuck in the tread surface. I can only describe it as bad luck, but as you can see from the damage to the head where it rubbed against the road surface, it was lucky that it didn't immediately lose air and run for a while after the screw was picked up.

As soon as I pulled it out, all the air that was left in the tube was released. The screw was 40 mm long, and the centrifugal force of the spinning tire did not blow it out, so it seemed to buy time to completely deflate.

Whether it's a tubeless or tube tire, a puncture can occur if you step on a nail, glass, or piece of metal. A hole in the tread surface will release the air inside the tire, but the process differs slightly depending on whether the tire has a tube or not. A tubeless tire, which literally has no tube, may be able to run with minimal air leakage until the punctured nail is removed, since the inner surface of the tire and the inner surface of the wheel rim are one air chamber. This is like a nail being a plug. Tube tires, on the other hand, are kept in shape by the air in the tube inside the tire. In other words, the inner surface of the tire and the tube are in close contact but in two layers. If a nail or a piece of glass gets stuck here and passes through the tread surface of the tire and punctures the tube, the air in the tube leaks onto the inner surface of the tire even if there is still a foreign object on the tread surface, causing the tire to lose air in a shorter time than a tubeless tire, in some cases all at once, affecting its handling stability. Riders who have experienced a flat tire on a bicycle will know the feeling of a tire losing air all at once. There are other causes of punctures besides nails and foreign objects. One such cause is a rim puncture (snake bite), which occurs when the tire is caught between the rim and the ground when riding over a bump, damaging both tubes at the same time. This tends to occur when the tire pressure is lowered when driving off-road models on forest roads. In addition, the type of tube fixed with a nut, which is often seen in tires for moped scooters, the valve is misaligned with the valve hole in the wheel, causing deterioration at the base and damage to the valve due to stress concentration. In addition, rim bands that set on the rim of a spoked wheel can shift or break, resulting in punctures caused by direct contact of the spoke nipple with the tube. Since the basic construction of a tube tire is the same for both bicycles and motorcycles, these cases can commonly occur. However, while a special repair kit is required to repair a puncture in a tubeless tire, the same tools can be used to repair a punctured tube in both bikes and motorcycles. Therefore, riders who have done DIY puncture repair in their bicycle days can use the same procedure to repair a punctured tube tire on a motorcycle.

Flat tire repair kits can be purchased at home improvement stores.

The tire lever is plastic and the bug rubber is for bicycles, as this is a flat tire repair kit for bicycles. The rubber patches and glue are the same as the ones you can buy at a home improvement store, but for the purpose of fixing a puncture in a tube, there is no difference between a bike and a bicycle.

To repair a puncture in a tubeless tire, you should have a bicycle puncture repair kit, which can be purchased at any home improvement store. A typical puncture repair kit may include rubber patches (multiple sizes), rubber glue, sandpaper, tire levers, and in some cases, a simple pump and CO₂ inflator. However, tire levers in bicycle puncture repair kits are generally made of resin only for bicycles such as mom-and-pop cars and light cars, so tire levers for bikes are required to repair bike tires. Also, as explained earlier, tube tires and tubeless tires have different puncture mechanisms and require different tools for repair. If a motorcycle supply store has a puncture repair kit for tubeless tires and one for tubular tires, be sure to purchase the kit for tubular tires. If the puncture repair kit has multiple rubber patches of different sizes, you must use different patches depending on the size of the hole. Using an oversized patch for a small hole may result in poor adhesion to the surrounding area. Also, rubber glue is not just a rubber-based adhesive. Some glues are vulcanizing glue, which chemically bonds the patch to the tube by the heat generated when the patch is run after repair. Sandpaper is essential to remove contaminants from the tube surface and to ensure the roughness of the bonding surface. An inflator or air compressor may be available for home repairs, but if you plan to work on the road, such as while touring, you should carry a portable air pump or CO₂ inflator along with your repair kit.

Be careful not to damage the tube with the tire lever!

The bead didn't fall off after the puncture and loss of air, so remove the wheel from the chassis and use a bead breaker to drop it off.

The bead is hard, so use a tire lever to flip it up. A protector was used to prevent damage to the rim, but the protector may pinch the tube on the inside of the wheel, so push the tube in (away from the protector and tire lever) beforehand.

The specific repair procedure is basically the same for both bicycles and motorcycles. It depends on the situation whether you want to remove the wheel from the vehicle or work on it while it is still attached to the vehicle body. If you have a flat rear tire with a center stand, you may be able to pull out the tube without removing the tire, but it is often easier to work on bikes with only a side stand by removing the wheel. Next, use the tire lever to remove the bead from the rim and pull out the tube by flipping one side. If the tire is almost the same size as a bicycle, such as a Super Cub, you may be able to flip the bead and pull out the tube using your fingertips without using the tire lever, but it is safer to use the tire lever for medium-sized or larger vehicles with a hard bead. In this case, be careful not to make a new hole in the tube by inserting the tire lever through the gap between the rim and the bead. Many puncture repair failures have been caused by damage to the tube caused by the tire lever. After pulling out the tube, locate the hole by lightly inflating it and soaking it in water, or by probing for air leaks with your ears or fingers. Once located, the area around the hole is sanded to improve adhesion, and a thin, even layer of rubber glue is applied. The key is to allow the rubber glue to dry for a certain amount of time, and then crimp the patch when it is semi-dry (some repair agent manufacturers may indicate complete dryness). After crimping, press firmly to ensure complete adhesion. Then lightly inflate the tube again to make sure there are no leaks, and place the tube back into the tire. It is effective to slightly inflate the tube during this process to prevent it from twisting or biting. Also, when using the tire lever to fit the bead, be careful not to damage the tube. Finding the puncture hole and applying the patch is the easy part, but if the tube and tire bite or re-puncture when restoring the tube and tire, you will have to go through the process twice, which is not pleasant, so each step must be done carefully.

If the tube is pulled out without displacing the wheel and tire, it is easier to locate the hole in the tube by relying on scratches on the tread surface. However, even if you find a hole that appears to have been opened by a screw, there may be other holes, so inflate the tube by itself and check the entire tube.

Roughen the surface by rubbing with sandpaper around the hole area and over a larger area than the patch to be attached, and apply rubber glue. As with rubber adhesives such as Bond G17, wait until the surface is semi-dry or completely dry before applying the patch, since adhesive strength cannot be obtained if the surface is wet.

The patch used was the type sandwiched between a transparent film and aluminum foil; the aluminum foil was peeled off, leaving the transparent film in place, and the patch was applied to the puncture hole, then crimped with a hammer or tire lever before the film was removed. If the rubber glue used is vulcanized adhesive, it will adhere more strongly when heated by running.

Let's review some important points to keep in mind when repairing.

Fill the tube with air by itself and check for leaks from the repaired part and holes elsewhere before assembling it on the wheel. When fitting the bead, it is best to have some air in the tube to prevent it from twisting or becoming uneven, but be careful not to have the inflated tube near the rim or bead as you risk damaging it with the tire lever.

As any rider who experienced puncture repair as a bicycle boy knows, the most important precaution in the operation is not to complete the repair without removing the cause of the puncture. It may seem obvious, but there have been instances of failure such as when a tire was restored with a foreign object remaining between the inner surface of the tire and the tube, only to have it punctured again as soon as it was inflated, or when the lever went missing from a large vehicle after the rider thought he had managed to fit the bead of the tire with the tire lever, and upon closer inspection found that it had become caught inside the tire, along with the bead. There is also a joke-like story of a large car bead that somehow managed to fit with a tire lever, but the lever went missing. It is also important to wait until the solvent has volatilized and the glue has become tacky, rather than applying the patch immediately after the glue has been applied. Furthermore, if the tube is severely damaged or if there is a hole at the base of the valve, patch repair is not an option, and tube replacement is a prerequisite. During assembly, the bead must be pressed in evenly to avoid tube bite, and finally, the air pressure must be accurately controlled to the specified value. Especially when driving on highways with on-road vehicles, the condition of the tire directly affects safety, so it is essential to check the reliability after repair. Even if emergency repairs during touring allow the vehicle to continue driving, it is advisable to carry out permanent repairs or tube replacement as soon as possible. It is important to ensure that these basic items are not neglected when repairing a puncture in a tube tire.