what's a good size tire to use? i've been looking on ebay and seeing high pressure 20" tires from about 1.35"-2.3". just from trying to look at g-bike pics it looks like they're around the 2" range. nothing i have around the house is more than the usual 40-60lb range, except a 1.5" 100psi i got for a specific bike that i don't want to take off, and a flea market find (hoffman 110psi 1.9") i put on the poseur 'cause it had white letters like the occ tire. since i'll have to buy them i might as well be looking for the best size. thanks.