D660
For the manufacture of concrete and for construction, sand and crushed stone are needed. Both are mined in quarries. The extracted rock for subsequent processing or use is transported on a special transport - an on-road dump truck. What makes this technique different from other trucks?
First of all, there is a difference in carrying capacity - at least 10 tons of bulk cargo is placed in an extensive body of a dump truck. Well, now let's imagine how a load of this weight is distributed. Of course, about 90% of the load falls not somewhere, but on the driving wheels - the rear wheels, which are located directly under the body's center of gravity. And mind you, this does not include the weight of the truck itself!
Well, the next question arises - what should be the tires that will withstand such a load for a long time? There are such tires, this is the D660. We will talk about these tires in this review.
Very durable tires at a glance
The D660 is a radial directional all-season tire designed to fit the drive wheels of a dump truck. The characteristic "radial directional" means that the tires must be positioned on certain sides of the vehicle and not otherwise. The fact that they should be mounted on the drive wheels means that these tires will perform best on the rear (not steering) wheels. The difference between these tires and steering tires is that they are designed to provide maximum traction and provide maximum traction to move the truck.
D660 is one of the most promising and technologically advanced truck tires produced by General Tire. General Tire is a US pneumatic tire manufacturer. Since the 1980s, General Tire has become part of the Continental AG concern and manufactures its tires using American and European technologies. Of course, this has benefited the quality of the products.
How tire grip is ensured
Dump trucks are used alternately on asphalt and unpaved surfaces. Conclusion - tires should drive equally efficiently on different surfaces. For this, a special cross-country tread is used in the design of the D660 tires. The tread is formed by three radial strips of blocks, separated by grooves, which provide engagement and drainage.
Since the tires are designed for use on asphalt and rough terrain, the tread height (dividing groove depth) is 30 mm. This is practically the standard for off-road tires with an aggressive pro-rector pattern. The advantage of such a tread is not only that it goes well on the road and off-road. The D660 tires, thanks to their pronounced tread, perfectly ride on dry, wet, and snowy surfaces. This is what makes these tires all season.
How tire strength is ensured
Conventional truck tires under the enormous pressure of the weight of a road dump truck would simply burst. How is the high durability of these tires ensured and why do they remain intact throughout the entire service life? It turns out it's all about the design of the tire and the choice of manufacturing materials.
Like most modern tires, the D660 is a technically challenging multi-layer tire. Each layer performs a specific function and is accordingly made of the appropriate material. For example, to last as long as possible, the tread is made of an extra dense rubber that does not wear off for a long time.
The layer to which the tread blocks are directly attached is more elastic since it does not come into contact with the road surface. The rest of the layers are reinforced with metal wire and metal belts to withstand significant loads. These layers are made of rubber with the addition of polymer fillers, which increase the strength and density of the material without increasing the weight of the tire.
Tire reinforcement
Reinforcement is made of wire weaving, which is located across the tire with a diagonal deviation. Another element in the tire construction is steel belts (belts), which run along the center rib and ensure that the tire adheres evenly to the road surface. This advantage translates not only into the durability of the tire but also more even wear of the tread, as a result of which the tire does not require replacement for longer periods.
The wire reinforcement of the tire is connected to metal cords located along the inner radius of the tire, that is, where the tire rests on the rim. Such a reinforcement scheme is not new and is used on almost all car tires, but in D660, weaving is done tightly and with a wire of a larger diameter. Thanks to the lateral and longitudinal reinforcement, the tire retains its shape even when the truck is fully loaded.
Like all modern General Tire truck tires, the D660 features reinforced sidewalls. This is a very important point since when unloading the contents of the body, the dump truck does not caustically run into obstacles such as curbs. Thus, the reinforced sidewalls extend the tire life.
Why are these tires good?
Summing up the story about the design features of the D660 tires, let's try to determine the advantages and disadvantages. There are many advantages and among them:
- Resistant to high internal pressure. However, this is not surprising when you consider what kind of cargo the dump truck transports.
- Excellent grip. Thanks to the pronounced tread, the tire literally clings to the road surface and drives the dump truck.
- Equally high performance on a variety of road surfaces, including asphalt and dirt. This is again due to the tread pattern and its increased height.
- The protector remains clean. The bottom of the grooves dividing the tread blocks in these tires are not made even - there are technological reliefs here. As a result, the soil and especially small stones, falling into the tread gaps, do not linger there for a long time.
- It becomes possible to increase the vehicle load in comparison with other tires. On average, thanks to the use of the D660, a tipper body can carry 10-15% more cargo than conventional truck tires.
- Durability. Thanks to specially selected tread materials and reinforced sidewalls, these tires can last for about 2 years. In comparison, conventional heavy-duty truck tires have a service life of about a year.
Are there any disadvantages? As such, there are no shortcomings, but you need to remember that this is an all-season rubber, which in winter in extreme icy conditions can hardly be compared with a special winter tire. Just keep this in mind when operating.
Some technical characteristics
- Let's start with the sizes. D660 tires are available in 2 sizes - 11R24.5 and 11R22.5. Perhaps these are the most common sizes, and therefore these tires are likely to fit most dump trucks.
- Load index - "N". This indicates that the tire is adapted to long-term high loads.
- With a tread height of 1.3 inches, this is an almost off-road tire that will provide maximum traction on the ground.
- The weight of one tire is 136 and 127 lbs, depending on the size.
- The maximum permissible speed is 70 mph, which is more than enough for dump trucks.
Let's summarize
D660is an all-season tire designed for tipper drive wheels. The tire is universal in the sense that it is suitable for installation on-road and mining dump trucks. The tire demonstrates excellent driving characteristics and has a long service life. Conclusion - these are excellent tires from a manufacturer with a good reputation.