Tires 101: An Introduction: Difference between revisions
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[[Category:Tires]] | [[Category:Tires]] | ||
==The Mystical Art of Tire Reading== | |||
It's black, it's round, and it goes on the wheel. | |||
Tires are a mysterious thing. Think about it: A reinforced bladder with about thirty pounds of air is all that keeps your motorcycle from rolling on its bare metal rims. That thin bit of rubber is what lets you get out there and enjoy a good ride. Obviously, it pays to know about your tires. | Tires are a mysterious thing. Think about it: A reinforced bladder with about thirty pounds of air is all that keeps your motorcycle from rolling on its bare metal rims. That thin bit of rubber is what lets you get out there and enjoy a good ride. Obviously, it pays to know about your tires. | ||
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The most apparent difference between tires is the size and the aspect ratio. These are indicated by the numbers on the side of the tire, usually something along the lines of "120/80V-16" or "4.50H-16". There is also an alphanumeric system that would look something like "MR80H-16". So what do all these numbers mean? | The most apparent difference between tires is the size and the aspect ratio. These are indicated by the numbers on the side of the tire, usually something along the lines of "120/80V-16" or "4.50H-16". There is also an alphanumeric system that would look something like "MR80H-16". So what do all these numbers mean? | ||
====Metric sizing==== | |||
Let's take a look at the most common designation, the metric system for tires. This is the one that reads "120/80V-16". This type of designation is the one that's most commonly used nowadays, and would break down as follows: | Let's take a look at the most common designation, the metric system for tires. This is the one that reads "120/80V-16". This type of designation is the one that's most commonly used nowadays, and would break down as follows: | ||
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The last number is the diameter of the wheel that the tire is intended for. In this case, we are talking about a 16 inch rim for the tire. | The last number is the diameter of the wheel that the tire is intended for. In this case, we are talking about a 16 inch rim for the tire. | ||
====American sizing==== | |||
The second example above reads "4.50H-16". This is the so called American system, and reads as follows: | The second example above reads "4.50H-16". This is the so called American system, and reads as follows: | ||
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The American system is a little quirky when it comes to aspect ratio. Generally, a tire is a high profile tire, with about a 90% aspect ratio, unless the width is indicated with a ".10" or ".60" designation. This indicates a lower profile tire, on the order of 75-85 percent. Thus, a 4.5 inch tire with an 85 percent aspect ration would be shown as a 4.60. A 4.0 inch low profile tire would be a 4.10. | The American system is a little quirky when it comes to aspect ratio. Generally, a tire is a high profile tire, with about a 90% aspect ratio, unless the width is indicated with a ".10" or ".60" designation. This indicates a lower profile tire, on the order of 75-85 percent. Thus, a 4.5 inch tire with an 85 percent aspect ration would be shown as a 4.60. A 4.0 inch low profile tire would be a 4.10. | ||
====British sizing==== | |||
The last method of tire designation is the British system, which we showed above as "MR80S-16". This breaks down like so: | The last method of tire designation is the British system, which we showed above as "MR80S-16". This breaks down like so: | ||
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Since the British system uses an alpha code for the tire width, a table is included below to indicate what metric and American widths are included. The table also includes the recommended rim widths for those tire widths. | Since the British system uses an alpha code for the tire width, a table is included below to indicate what metric and American widths are included. The table also includes the recommended rim widths for those tire widths. | ||
==Speed Ratings== | |||
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==Tire Size Conversions== | |||
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==Interpreting the sidewall data== | |||
Okay, so we've got the codes... but what does it mean? How does a 130/80-16 differ from a 120/80-16, if both can fit on the same size rim? | Okay, so we've got the codes... but what does it mean? How does a 130/80-16 differ from a 120/80-16, if both can fit on the same size rim? | ||
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All in all, this means that a wider tire will tend to steer more heavily, but will also offer more traction. A larger rim will also steer slower, as will a broad, relatively flat tire. | All in all, this means that a wider tire will tend to steer more heavily, but will also offer more traction. A larger rim will also steer slower, as will a broad, relatively flat tire. | ||
==Buying the right size== | |||
So, what does all this mean when it comes time to go out and buy the tire? Well, it means a lot. First of all, in many cases the tire selection may be limited by the wheels on the bike, or the age and style of the bike. An excellent example of these limitations is found when attempting to find tires for a pre-1994 EX500, or for a Ninja 600 (NOT the ZX-6). Both of these bikes have relatively narrow 16 inch rims, but they are also meant to be more sporting motorcycles. The selection of quality rubber for these bikes is pretty limited. You will find the same thing when you go looking for tires for the Ninja 250. | So, what does all this mean when it comes time to go out and buy the tire? Well, it means a lot. First of all, in many cases the tire selection may be limited by the wheels on the bike, or the age and style of the bike. An excellent example of these limitations is found when attempting to find tires for a pre-1994 EX500, or for a Ninja 600 (NOT the ZX-6). Both of these bikes have relatively narrow 16 inch rims, but they are also meant to be more sporting motorcycles. The selection of quality rubber for these bikes is pretty limited. You will find the same thing when you go looking for tires for the Ninja 250. | ||
In other cases, while the hardware may be capable of supporting a more current tire, the optimal sizes are not available. A good example of this is the 1986 VF1000R, that has a 2.75x16.0 inch front wheel and a 3.50x17.0 inch rear wheel. The fitment of rear tires is not a problem -- any of the quality 140, 150, or 160 width radials will fit nicely. The slightly narrow front, however, really works best with a bias-ply tire. As for the EX250, there are good tires available, but they're not necessarily the "perfect" size. That's where the above charts come in handy. (See also the [[What tire makes are available that fit the 250?|Tire Models Page]]). | In other cases, while the hardware may be capable of supporting a more current tire, the optimal sizes are not available. A good example of this is the 1986 VF1000R, that has a 2.75x16.0 inch front wheel and a 3.50x17.0 inch rear wheel. The fitment of rear tires is not a problem -- any of the quality 140, 150, or 160 width radials will fit nicely. The slightly narrow front, however, really works best with a bias-ply tire. As for the EX250, there are good tires available, but they're not necessarily the "perfect" size. That's where the above charts come in handy. (See also the [[What tire makes are available that fit the 250?|Tire Models Page]]). | ||
==Radials== | |||
And that brings us to an important matter for tire buyers -- should I buy a radial tire? The answer is a firm "maybe". (The answer for EX 250 owners is a firm "uhh, forget it.") First of all, it helps to know the difference between a radial and a bias ply tire. To understand the difference, it helps to know a little bit about tire construction. | And that brings us to an important matter for tire buyers -- should I buy a radial tire? The answer is a firm "maybe". (The answer for EX 250 owners is a firm "uhh, forget it.") First of all, it helps to know the difference between a radial and a bias ply tire. To understand the difference, it helps to know a little bit about tire construction. | ||
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Okay, so what does it mean? Well, a bias-ply tire requires a minimum of two layers to support the sidewall and the tread. The layers are fairly stiff, and essentially must scissor against each other to flex. This makes the tire run hotter. A radial tire needs only one ply, and thus is not only softer, but runs much cooler, and weighs less to boot. Advantages all around -- lighter, cooler, more compliant. This means that not only can you run a softer compound for radials, but it will provide better grip since it can conform to the road better. Great! | Okay, so what does it mean? Well, a bias-ply tire requires a minimum of two layers to support the sidewall and the tread. The layers are fairly stiff, and essentially must scissor against each other to flex. This makes the tire run hotter. A radial tire needs only one ply, and thus is not only softer, but runs much cooler, and weighs less to boot. Advantages all around -- lighter, cooler, more compliant. This means that not only can you run a softer compound for radials, but it will provide better grip since it can conform to the road better. Great! | ||
But wait! There's a catch -- radial tires require wider rims to support the same tire width. That means that a 120/80 bias ply tire would work on a 2.5 inch rim, but a 120/80 radial would need a 3.0 inch rim to support it properly. Why does a radial need a wider rim? In simplest terms, a radial tends to have a softer sidewall, and a wider rim with a similar aspect radial puts less load on the sidewall, causing it to distort less under load. Most radials are designed for wider wheels, and putting them on a narrower rim will distort the cross-section of the tire and affect the handling of the bike -- almost always negatively. | But wait! There's a catch -- radial tires require wider rims to support the same tire width. That means that a 120/80 bias ply tire would work on a 2.5 inch rim, but a 120/80 radial would need a 3.0 inch rim to support it properly. Why does a radial need a wider rim? In simplest terms, a radial tends to have a softer sidewall, and a wider rim with a similar aspect radial puts less load on the sidewall, causing it to distort less under load. Most radials are designed for wider wheels, and putting them on a narrower rim will distort the cross-section of the tire and affect the handling of the bike -- almost always negatively. | ||