I have a question about suspension forks that have a pre-load knob only on one side. I believe having it on one side only is not uncommon, and the other side is often equipped with a lock-out knob. My question is: why is there a pre-load knob only on one side. Particularly for rather simple (low-end) coil suspension forks having only one knob seems to imply that you are pre-loading only one of the two coils in the fork, while the other spring would remain unchanged.
1) Is this assumption (that only one of the two coils gets pre-loaded) correct?
2) Why is it done like this? (Would this be done to have the "sag distance" still be covered by the other coil?)
3) Doesn't pre-loading only one of the two coils cause an unfavorable asymmetry?