Well there are a couple things. About the multi piece vs one piece wheels is rigidity and wieght. Single piece wheels are much more ridgid. This makes a difference in wheel integrity but not much else. Mostly its wieght. Multi piece wheels require more and thicker parts to keep the wheel hole and in one piece. So you just end up with more wieght and less strength, and in my opinion those ugly ass rivits on the outside of the rim. As for 18"vs 19"... (im saying this assuming your keeping the correct wheel spin ratios) 18 will always be a smoother ride than 19 because your using more rubber. One thing to consider is wieght, of the rim and the rubber. The point is not always to keep the wieght to a minimum but to have good wieght distribution, on wheels this means getting rid of centerfugal inertia. What I mean by this is usually people think about the wieght of the wheel, but the rubber actually can be much heavier than the new aluminum alloys good wheels use today. The wieght of the thicker wall 18 inch tire may be heavier/lighter/same as the weight of the thinner yet larger circumference 19 inch tire. Im not sure which is, best i can say is go to tire store and get some measurments. But if the 19 inch is lighter then your keeping more wieght (the metal wheel) to the inside resulting in less centerfugal inertia = wheels can spin faster, like getting a lighter flywheel. Well i probly didnt explain it as good as i can, if i explained it good at all, but i gave it a try. Im goin back to imitating pauly shore now.
FReeee MAHI MAhI
<span style='font-family:Geneva'><span style='font-size:14pt;line-height:100%'><span style='color:red'>Fox</span></span> <span style='color:gray'>the Pirate</span>
Diplomacy is saying "nice doggy" until you find a rock.</span>
I live my life one quarter mile at a time, and for those 23 or more seconds I'm free.