Width
Nominal tyre width (section width) in millimetres. This is one of the notation options; in addition to it, there may also be a designation in inches, for more details, see "Width" above.
Width — whether in millimetres or inches — is one of the parameters that determine compatibility with a particular rim (the other parameter is the fit diameter, see above about it). The main criterion for choosing a tyre in width is the manufacturer's recommendations for a given motorcycle model. It is highly undesirable to deviate from these recommendations: although some types of motorcycles (for example, road bikes) allow a width deviation of +/— 10 mm on the rear wheel, such a wheel will still function in a mode that differs from the standard one. On the front wheel, no deviations are allowed at all.
Profile
Tyre profile height. This parameter is specified as a percentage of the profile width (see above).
The higher the profile, the better the motorcycle can carry heavy weight and increased loads when driving on rough roads and the lower its stability at high speeds. Therefore, for high-speed driving on high-quality flat tracks, hard-surface motorcycle tracks, etc. use ultra-low-profile rubber, with a profile height of up to 60%. For most east european roads, given their overall quality, rather low-profile tyres are recommended — 60 — 80%. And tyres with a profile height of more than 80% should be chosen when the key points are not speed, but cross-country ability and resistance to stress.
Now on the market there are tyres with the following profile height:
40%,
50%,
55%,
60%,
65%,
70%,
75%,
80%,
90%,
100%.
Rim diameter
Tyre inner diameter. This value must correspond to the rim diameter of the wheel on which the rubber is planned to be installed — otherwise the installation will not be possible. You can find out the size of the wheel from the documentation for the motorcycle, from the markings on it, according to the characteristics of the old rubber (if the tyres are bought for replacement), in extreme cases, you can measure the diameter of the disk yourself.
Now on the market tyres with the following diameters:
10",
11",
12",
13",
14",
15",
16",
17",
18",
19",
21".
Load index
The load index indicates
the maximum weight load that the tyre can safely carry in normal operation. To shorten the marking, this parameter is denoted by a two-digit number; you can translate this designation into a specific weight in kilograms using special tables.
This value must not be exceeded — otherwise the tyre may burst at any time due to off-design loads. At the same time, when choosing motor tyres for this parameter, it is worth remembering that the load is distributed unevenly between the front and rear wheels. However, the task is facilitated by the fact that motorcycle manufacturers can indicate the minimum or recommended load indices for the front and rear axles in the documentation for their equipment.
Design
The design of the tire depends on the arrangement of the cord threads - a special fiber that gives the rubber base additional strength and rigidity.
-
Radial. In radial models, the cord fibers are located across the tire, parallel to its radius. Such tires are not as prone to heating up as diagonal tires, so they can easily provide a high speed rating (see below). At the same time, radial models are poorly adapted to high weight loads, and their profile is generally flatter and lowered. Therefore, a similar design is found mainly in high-speed tires for sports and road use (see “In the direction”), intended for sport bikes and other relatively light equipment. However, enduro class models can also use this option; but among cross-country ones it is practically not used.
-
Diagonal. In bias-ply tires, the fibers are arranged in the form of a characteristic grid, intersecting each other at an angle of about 40–60°. Such tires heat up more when driving than radial tires, which is why they are poorly suited for high-speed driving. On the other hand, the bias-ply design makes it possible to create high-profile tires with a high load index that can withstand driving well on uneven roads. Therefore, this particular option is used in road tires designed for heavy equipment such as choppers and cruisers, as well as in cross-country models.
