Rim diameter
The tyre diameter is the diameter of the rim for which it is designed. This is one of the main parameters (along with the width) that determines compatibility with a particular ATV: the tyre diameter must match the size of the disk. This size must be indicated in the documents for the machine, in addition, it can be applied to the disk itself.
The most widespread among modern ATVs are tyres with a diameter of
12 " and
14", smaller sizes are somewhat less common —
10",
9",
8", and even
7" or less.
Width
Nominal tyre width; measured along sidewalls in uninflated/unloaded condition. This is one of the parameters on which the possibility of installation on a particular ATV (along with the rim diameter) depends. However, the requirements for the width are somewhat softer than for the diameter: on stock ("native") disks, tyres with an excess of the recommended width by 1", on some non-stock disks — up to 2" are allowed. These nuances are described in more detail in special sources. However, for maximum warranty, it is better not to deviate from the recommendations specified in the documents for the ATV or wheels, and use tyres with the width that is directly recommended by the manufacturer.
The tyre width options that are relevant for modern ATVs are
7",
8",
9",
10",
11",
12".
Tyre height
The nominal height of the tyre, in other words, its outer diameter in an uninflated / unloaded state.
The main meaning of this parameter is compatibility with a particular ATV: the optimal tyre heights are usually indicated in the documents for the machine or the disks installed on it. At the same time, in some cases, it is allowed to increase the height by 1" when using stock ("native") disks and by 2" on some non-stock ones; however, it is still best not to deviate from the manufacturer's recommendations.
As for the specific height values, they are strongly related to the bore diameter. So, all tyres with a diameter of up to 10 "have a small height —
22" or less. The minimum figure for models for 12" wheels is
25", for 14" wheels —
26" ; in both of these varieties, there are also products with a height of
27 ",
28" and even
29" or more.
Also note that its patency and ability to overcome various irregularities depend on the height of the tyre. With the same seat diameter (see above), a larger overall height gives a greater sidewall height: for example, in tyres with a diameter of 12 "and a height of 25" on both sidewalls there will be 25" — 12" \u003d 13", that is, 6 each, 5" (about 16.5 cm) per sidewall, and with an overall height of 28"
...the height of the sidewall is already 8" (about 20 cm). And here it is worth remembering that for inflatable wheels, the height of the vertical obstacle to be overcome, ideally, should not exceed the height of the sidewall.Ply Rating
The ply rating (Ply Rating, PR) to which this tyre model corresponds.
Ply Rating is a comprehensive indicator that describes the ability of a tyre to withstand high loads in terms of weight, traction and pressure (including when hitting various obstacles). This parameter is important primarily for tyres operating under increased load conditions — and tyres for ATVs are most often used in this way. PR is indicated as a number indicating how many layers of cotton cord the strength of this tyre corresponds to (such a cord was used in tyres of the old design, now it is no longer used). Accordingly, the larger the number in the designation, the stronger and more reliable the tyre. On the other hand, increasing the ply rate increases the weight and cost of the product. Thus, some models are produced in several PR variants to choose from (for such models, the rating options are indicated in the notes to this paragraph).
The minimum ply rating found in modern ATV tyres is
2PR. However,
4PR and
6PR models are more popular.
8PR is already considered a very solid value, and the most “hardy” products correspond to 10PR. The optimal PR values can be indicated in the documents for the ATV, and recommendations on this matter for different situations can be found in special sources.
