AT405 Radial

 

New 38 Inch Tire

The most advanced species have survived because of their adaptability. They owe their advantage to chance.
-Charles Darwin

Arctic Trucks is now introducing to the Icelandic market the first big off road tire specially made for driving on snow and wet conditions.

 

AT405 radial is like the name suggests a radial tire and it measures 38 inches high.

The design in based on experience gained by Icelandic 4 wheelers through the years. Preparations began for real in the year 2000 and design, prototype building and testing has continued to this day.

The tire is manufactured by the fourth largest tire manufacturer in China.

A total of 800 have been put on sale in Iceland and it is not clear at this moment if or when it will be introduced to the international market. That will depend on how Icelandic off road enthusiasts like the tire in comparison to other 38 inch tires.

AT405 Radial

 

Key Points

  • Designed from the ground up as a winter tire
  • Siped from the factory
  • Stands 38.1" tall (Mudder is 37.55")
  • Same tread width as the old Dick Cepek (27cm)
  • Designed for 12"-14" wide tires
  • 6 layers of cords (Load Range C), bearing 1365 kg pr tire
  • Rubber characteristics are resistant to temperature changes
  • Tread is between all terrain and mud terrain with 55% rubber/space (Mudder 45%, Cepek 60%)
  • Equal coarseness over the tread width
  • Directional pattern with open pathways for flow of water and ice
  • Spike distribution is irregular and therefore uses each spike better
  • Irregular space between rubber cubes causes significant noise reduction

AT405 Radial

 

Details

AT405 Radial

  • Tire is curved over the tread making the tire wear even and sit better
  • Tread thrust angle is 14° - same as in most new winter tires
  • Tread depth is 17mm or 2mm more than other tires in this size
  • Spike holes are designed for 4x4 spikes

 

AT405 tires are made in multi-molds

AT405 Radial

For many years big off road tires have almost exclusively been made in sandwich molds. Where two forms are laid together with only one seam at the middle of the tire. Multi-molds are more expensive but they insure better results because the weight distribution will be even.

 

Traction in snow and ice, self-cleaning of water and snow

AT405 Radial

With 12mm deep w-patterned sipes the AT405 gives especially good traction in slippery conditions and snow. Medium soft rubber helps giving a better grip.

Technical measurements

AT405 Radial

Driving at the speed of 90 km/h shows the AT405 measured the noise level at 83.5 dB compared to the Mudder at 87.1 dB.

AT405 Radial

Tire heating with too little air in the tires shows that this happens closer to the tread on the AT405 tire than in other comparable tires. This should mean better cooling when driving on snow.

 

AT405 Radial

Mudder

Here you can see how these tires chance shape differently even though they have equal air pressure.

 

AT405 Radial

Mudder

A simple wear experiment shows how a duct tape deteriorates at different locations on similar tires. You would think that even wear of the tape indicated even wear of the tire and how well it sits on the surface.

 

AT405 Radial

Mudder

Here you can see how these tires form tracks in the snow.

 

AT405 Radial

At 3 psi you can see how the AT405 floats on the snow. Notice how all tread - all the way to the stripes on the sides - is working as intended.

Walk Analyzes

AT405 Radial

AT405 Radial

Freyr and the team tested how various tires touch the surface and how they behave using different air pressure. The measurements where carried out using special equipment from prosthetics company Össur.

 

20 psi in a non moving tire (below).

Dick Cepec                 Mudder                        AT405

Dick Cepec                 Mudder                        AT405

Dick Cepec                 Mudder                        AT405

3 psi in a non moving tire (above).

AT405 Radial

 

Mudder

AT405 Radial

2 psi in a non moving tire. Mudder and AT405. Notice how the tires have completely lost their ability to support the vehicle.

 

Rubber hardness

This graph shows how various types of rubber behave according to temperature changes. Yellow line is for the relatively hard prototype of the AT405 and the pink line is for the rubber that is used in the final production version.

In other words - the AT405 rubber blend stays softer in colder weather than comparable tires.

 

Warning

Arctic Trucks would like to point out the following:

Driving with too little pressure in tires can damage it and cause accidents.

All use of tires with lower air pressure than is recommended by the manufacturer is at the responsibility of the buyer/user.

Buyer/user is fully responsible for accidents and/or damage caused by neglecting to observe air pressure in tires.

 

 

Thrandur Arnthorsson
Thrandur is the chief-editor and owner of 4x4 Off Roads and an 4x4 off road enthusiast. Living in Iceland he loves to share the coolest 4x4 trucks and supporting more offroad freedom. Thrandur is the author of the Udemy course How to modify your cool 4x4 truck!.

Based on promotional material from Arctic Trucks.

 

 

 

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