An approach to the choice of tires for the leading axis

In a real motorsport 70% of sports car performance depends on the right choice of tires.

These sports tires have a lot of parameters and are the subject of a separate study .

In Rc Drift everything is much easier , but it is only at first glance.

Today are a lot of drift tires on the market, and selection of the correct onece could take time and money. In order to choose the right tire for your chassis and surfaces need to know the physics of the process , imagine that you are expecting from the tires and be able to check it.

Physical model of grip

The main characteristic of the tire - grip.

 The almost full list of factors affecting the grip:

 1) softness of the plastic compound - in direct ratio

 2) contact patch - in direct ratio

 3) weight from chassis - in direct ratio

 4) temperature (tire, ground, air et. cet.) - in direct ratio

 5) rotational speed - inversely

The "ideal" drifting tires

The tire must provide a constant and maximum grip. The main reception to send the rear axle slippage are increased wheel spining.

So the tire must be predictable at different levels wheel spining. Take a look at the picture. 

Green: A good grip from the start, but after 12000 rpm line went to the top. The cause overheating of the tire. Good but inconstant grip.Verdict too soft for such weight load. 

Blue: The ideal tire under the conditions. The grip uniformly decreases with increasing rpm. 

The graph is smooth and flat. The maximum and constant grip in these conditions. Verdict "ideal" tire. 

Red: The grip is unpredictably. Perhaps some technology tdefect of tire. Verdict - not use in any case. 

Purple: Another example of the ideal tire, really stable grip, but not the best possible! Verdict - use on more gripy surfaces.

An approach to a reasonable choice of tires

If you are lucky and you have the track near you. So follow the tire regulations rules of the track. 

If you are like I, was not so lucky you will have to choose tires by yourself. Here's how I did it.

This is just a DESCRIPTION OF THE METHOD if the tire did not satisfied me maybe they will satisfied you - need to check!

Materials and method:

Chassis - GRK global RWD. Full equipped (without shell) rear motor chassis.

Surface - very fine asphalt

Rear axis load - 550/550 gram

FDR - 10.5

Telemetry: SSL From Sanwa combo (Sanwa MT4S+SuperVortexTypeD) 

Traction measurement - No name electronic weigher.

List tires(based on recommendations rc drift communities from facebook and Vkontakte) 

Special thanks to Ds Racing for free samples!

• HPI T-Drift (4406)
• "T-Drift" no name Chinese
• Raikoudrift D20 (35900)
• D-racing FF zero 
• MST gold dot (101025)
• MST red dot (101024)
• Speedline CR-0 (770)
• Speedline CR-1 (771)
• Speedline CR-2 (772)
• Tamiya DriftTech

Results:

Conclusions:

1)The method works well

2)For my GRK global rwd On the surface used the best option for the rear axle is a Tamiya DriftTech 

( unfortunately they are available in 24 mm only) or MST gold dot.

3) All tires overheating(T- Drift, MST red , DS- races )

 Maybe re-testing at a lower load on the rear axle, or front motor chassis , 

 or on the more slippery surface.

 4)Speedline Cr-0 and Raikoudrift D20 - perhaps suitable for this chassis on the carpet .

5)Speedline Cr-1 and Cr-2  will not apply to the rear axle , under any circumstances.

6)The original T-Drift and his Chinese clone - have different properties.