What is steering dual rate? As the name implies it has something to do with rate of your steering! Also, ‘dual’ for two???
Many, if not all, radios these days come with a ton of features. One of those is Dual Rate (DR). The term dual rate is a little misleading. I’ve not seen a car/ truck radio where there are two (dual) steering rates. The control for the DR is of the knob variety (potentiometer) meaning you have a ‘range’ of steering rates. By varying the knob position (like the volume on a radio radio) you change the rate and affect the truck’s steering. This steering rate affects both left and right steering.
What Dual Rate affects is the amount of throw your servos have when you fully turn/move the wheel/ stick left or right. Normally, without DR, turning the wheel control full in either direction will result in the servo moving fully in that direction and causing the wheels to turn (max throw). Adjusting the DR will reduce the amount of travel from the servo when the control wheel is turned all the way.
For example, let’s say max throw for our truck causes the servo to move 60 degrees in either direction. Adjusting the DR knob will make it such that the max throw is now going to be less than 60 degrees. How much less than 60 degrees depends on the radio model and what the DR knob is set at.
What this boils down to is turning radius. Say at full throw, without DR, your truck has a turning radius of 2 feet. With DR turned on, your truck’s turning radius will now be larger than 2 feet! It may be 2.5 feet or 7 feet wide depending on your setting.
As stated, this steering rate adjustment affects both left and right steering equally. The response is still a linear proportional response – if you turn your control 50% the output will be 50% of the ‘new rate’. What is ultimately affected is how much the servo moves when the control is turned all the way.
Now, why would you want to have a wider turning radius? To reduce the trucks responsiveness. At low speed there isn’t an issue with a very tight turning radius. However, at higher speeds attempting to make tight turns could lead to traction rolls (the truck rolling over on its roof) from the over steer if there is adequate traction. Adjusting the DR (giving a wider turn radius) can reduce traction rolls.
A good tip is to adjust the DR so that you can comfortably make it around your tightest corner. Of course, you could always just not turn the wheel so hard!
So dual rate is a bit confusing but if you think of it in terms of turning radius it’ll make more sense. It comes down to preference whether you’ll use it or not. Some like the ability to have full steering throw and just adjust their use of the control instead of using DR. DR is great for reducing the trucks steering response. Something that could reduce the steering response and give you access to full throw is Expo! Hmmm….