Soft steering springs give slow, predictable steering, limit understeer and are relatively easy for a newbie in a big car-park. Stiff steering springs give a much better response at speed, making the bike more flickable but can make the bike understeer more in the corners, meaning you have to back off the steering at the transmitter more to tighten the line. This is counter-intuitive to a car driver, and possibly the hardest thing to get used to when you first race an RC bike. Ask me how I know this…
The best advice I had early on with steering set-up was this: use a long travel steering arm and stiff springs to get good response at speed. Make the springs a loose fit at rest with 1-2mm clearance at the straight ahead to allow the bike to track straight and mean you don’t have to back off the steering as much in a corner, reducing understeer.
A bike with this setup can be tuned quickly and easily to the track by increasing or decreasing the steering throw – use less when you want a calmer bike, more when you need quicker response.
Some riders prefer to use less travel or a shorter steering arm, with more compressed springs to give a faster response – this also works OK, but I personally find the bike too twitchy like this, my reflexes aren’t fast enough!
Either way works, it’s down to what you prefer at the end of the day.