Two days ago, I wrote to RANS' e-mail address for bicycles (as opposed to aviation), asking whether the RANS aluminum 20 in. fork would work on (i.e., be stoung enough for) a conventional bike. I have not heard back.
But, in any case, my first choice for a replacement fork would be high-quality steel, not aluminum or exotics.
So, does anyone know of a source for a 20 in., curved (non-BMX), chromoly replacement fork with a 1 1/8 in. threadless steerer ? ....