What are the signs that indicate wear limit?
There are three main factors that affect the lifespan of motorcycle tires:
1. The tread (surface of the tire) has reached its limit of wear.
2. The tire’s material has deteriorated.
3. Damage such as a puncture due to an accident while driving.
Of these, especially 1 and 2, you should always check your tires and see what their current condition is so that you can determine when they need to be replaced.
First, to know whether the tread (tire surface) has reached its limit of wear, check the “slip sign.”
Slip signs are raised areas in the tire grooves that serve as a guide to the remaining tread depth. As you know, as tires wear down, the grooves disappear and they are no longer able to perform their intended functions, such as grip. If slip signs appear on the tire surface, it is a sign that the remaining tread depth has reached 0.8 mm (the minimum tread depth for motorcycle tires as stipulated by the Road Transport Vehicle Act). This means that the tire has reached its limit of wear.
A slip sign is a raised area in the grooves of a tire.
To find out where the slip sign is located, check the mark on the tire sidewall (side of the tire). The mark is usually a “▲” mark, and although it varies depending on the tire size, it is usually located in 4 to 6 places. Note that, although this also varies depending on the tire size, in some cases the letters “TWI” are engraved instead of the “▲” mark.
The location of the slip sign can be identified by the “▲” mark on the sidewall (side of the tire).
If slip signs appear on any of the front or rear tires, it is dangerous to continue driving, so replace them with new tires. Also, when it comes to timing, it is better to replace the tires before the slip signs appear on the surface, rather than after they appear. It is safer to replace the tires when you think, “I’ll probably start seeing signs if I drive a little longer,” because it is before they reach their limit.
As mentioned at the beginning, tires are a very important part of a motorcycle for safe riding. Be sure to replace them as soon as possible.
Tires should be replaced before signs of slippage appear on the surface.
Even if there is a groove, if the deterioration is severe, replace it.
Even if your tires show no signs of slipping and have sufficient tread, they may need to be replaced. This is due to the “deterioration of tire materials” mentioned above.
For example, if the tire has cracks in the tread or sidewall due to aging, tires are, of course, made of rubber. As time passes after manufacture, the rubber hardens and cracks occur. Driving in this condition is extremely dangerous as it can cause the tire to burst while driving.
Tires with cracks should also be replaced.
Also, even if there are no cracks, it is a big no-no to not change your tires for, say, 10 years. This is also because the rubber has hardened, which means there is a high possibility that the grip has decreased. In particular, if you drive on slippery roads in rainy weather in this condition, the risk of falling increases significantly, making it dangerous.
Other dangers include external damage to the tread surface or sidewall that reaches the cords in the tire’s internal structure, or cracks in the rubber. These cases can also lead to tire damage, so replace the tire with a new one.
If you are unsure about this condition, we recommend that you consult a motorcycle shop or tire retailer that has expertise in tires.
What to do if you get a flat tire while driving
And then there’s the third case, “damage such as a puncture caused by an accident while driving.” This is when the tire itself is fine, but suddenly punctures while driving because the driver runs over a sharp object such as a nail on the road.
There have been cases where people have stepped on sharp objects such as nails on the road, causing flat tires.
Recently, more and more bikes are being fitted with tubeless tyres. If you have one of these models and you run over something sharp while riding and get a puncture, you can repair it on the spot if you carry an emergency puncture repair kit.
However, in this case, even if you are able to ride to some extent, it is only a “temporary fix.” Depending on the condition of the puncture, it is not possible to know for sure whether it is safe or not, so it is dangerous to continue riding as it is. As soon as possible, go to the nearest motorcycle shop or a store that specializes in tire changes and have a professional check it.
And unless an expert inspects it and says it’s okay, it’s safe to replace it. It’s probably best to think of this as reaching the end of its life.
Repairs using an emergency puncture repair kit should be considered only as a temporary measure.
If you don’t have a puncture repair kit, or if the tire is so badly damaged that you can’t continue riding even after first-aid repairs with the puncture repair kit, you’ll need to call the Japan Automobile Federation (JAF) or the road service included in your voluntary insurance to get rescue. Even in such cases, you should still go to the nearest motorcycle shop or a store that specializes in tire changes as soon as possible to have a professional check the tire and, if necessary, change it.
Daily inspections are important to prevent tire problems
Unless a tire suddenly gets punctured by a nail or something else while driving, it is important to check the condition of your tires on a daily basis to see if there are any signs of slipping, cracks, or scratches.
If possible, it’s best to check before each ride. Also, make sure your tire pressure is at the correct level. If you don’t drive with the correct tire pressure, it can cause abnormal wear, with uneven wear occurring in specific areas of the tread.
Incidentally, tire pressure can be dangerous if it’s too low or too high compared to the specified value. Low pressure causes the shoulders of the tread to wear out faster, while high pressure causes the center of the tread to wear out faster, both of which are prone to abnormal wear. These factors can lead to the risk of the tire getting a flat or bursting while driving. Unlike stepping on a sharp object like a nail, as mentioned earlier, this can be prevented by checking in advance. We highly recommend that you practice this.
Tire pressure can be dangerous if it is too low or too high.
In addition, tire pressure also changes depending on the weather and temperature of the day. Therefore, if possible, it is safer to check the tire pressure before each ride and adjust it to the appropriate pressure for the conditions of the day.
The proper tire pressure for your vehicle can be found by looking in the owner’s manual or on a sticker attached to the chain case, etc. The proper tire pressure varies depending on the type of motorcycle and engine displacement. Also, some models require higher tire pressure when riding with two people. We recommend that you always check the specified tire pressure and conditions for your vehicle in advance and check them frequently.
The proper tire pressure is also written on a sticker attached to the chain case, etc.
How you store your bike can affect the lifespan of your tires
To extend the life of your tires, it’s a good idea to pay attention to how you store your bike. If possible, storing it indoors in a garage or other location will protect it from rain, wind, and direct sunlight, which will help prolong the life of not only your tires but also your bike’s paint.
However, if you can only park your bike outdoors, we recommend that you cover it with a motorcycle cover. Tires are particularly susceptible to the effects of ultraviolet rays and heat from sunlight. Therefore, if you expose them to ultraviolet rays for a long period of time or leave them on hot asphalt for a long time, the rubber will deteriorate and become more susceptible to the cracks mentioned above.
If you can only park outdoors, we recommend using a motorcycle cover.
Of course, motorcycle covers will deteriorate if used outdoors for a long time. If you continue to use a motorcycle cover that is worn and torn, it will no longer protect the motorcycle or tires, so it also needs to be replaced regularly.
As we’ve said many times before, the tires on a motorcycle that runs on just two wheels, front and rear, are extremely important for safe and stable riding. That’s why it’s so important to always know the current condition of your tires. We hope you’ll regularly carry out the checkpoints introduced here and enjoy a safe and secure motorcycle life.
