Magic Number!
 

Woo Hoo! I found my magic number! I started out at 32-15 on my MTB that I converted and was riding around on the road. Yea, it was way too low but I've developed a monster spin. Or at least that's my excuse. But I could spin out at will on any part of my 50 mile ride, it was time for a change. Dropped the rear to 13 (still too low, but it's what I have around) and checked a few things and guess what? No more derailer needed! I'm just a normal SS bike now. I'm so happy and the bike rides 10000 times smoother. Now if I'm right, as long as I keep the front + rear in increments of 4 teeth from this magic number of 45 then it will always fit. Right?
I'm so happy, makes me want to get a fixed hub. I can't wait to go for a ride this weekend. :D