I had a lot of false neutrals when I started riding a brick, I was doing a few things wrong. Taking up the slack before changing helped, but as mentioned, if the revs drop too much, the synchros have to work too hard. My biggest mistake, I was changing gears before the revs got high enough. If your previous bike was a cruiser for example, you might be changing too early. Bricks love high revs, and I thinks you will too if you give it a try and get used to it. After a while you might even forget you had a false neutral issue.