Don't know if anyone has tried this and I couldn't find a thread about it.
I thought my ZZ was turning too quick and tried puting 2 steering springs on and that didn't seem to help much. So I went back to 1 spring and put a tiny piece of tape over the steering spring.
At first the tape was as far up, to the little tabs the end of the spring goes under, and it was too stiff. Would not turn. So I moved it back a little and it seemed to slow down the steering. It did take me about 3-4 adjustment to get it where I liked.
i put tape over the front tires...it goes straight when i need to..i can make VERY small adjustments at high speed if i need to...and it'll steer when i'm at a dead stop