The factory "brace" is really just a fender bracket, but better than nothing at all, I guess. I shudder when I see bikes with no fender, and no brace either. Regardless of how many discs you have, as Mick says, a fork brace will stop the fork legs from "walking".
I've got one on my Suzuki GS1000S, which is probably the best handling Jap bike from the 1970's anyway, so no big difference when just tooling around, but it does feel a little more "planted", particularly when pushed hard thru the twisties under brakes.
They were very popular with Kawasakis back in the day, for many years the words "Kawasaki" and "handling" were mutually exclusive. Cheers, Terry.
