18 inch rear wheel Vs 19 inch rear wheel ?

[kiwikx500]

In what areas are one better than the other over  ?

[Paul]

19's are better on a MX track, 18's are better in rocky areas like open desert races. The extra sidewall on the 18 helps to avoid pinch flats.

[gowen]

19s are lighter. That is the only effect I know of.

[alan]

You can run a 560 Paddle with an 18!

[Danger4u2]

So, what you guys are saying is 18" doesn't handle any better than the 19", the 18" just has more tire options.
Is that correct?

Danger

[gowen]

19 handles better than an 18. It is a lower profile. 18 gives in corners at a track. It depends on the ride.

[kiwikx500]

Very interesting,i thought the 18 would be lighter and it would be better around a tight motorcross track - looks like i might be best changing to a 19 inch in time (prefer original anyway) if the only main advantage of the 18 is in a rocky desert - none of them around here - as murphys law would have it,its the front hub that really needs replacing with its shot spokes,the 18 rear in good condition,cheers

[gowen]

18in. tires have more rubber and are taller, so have horrible give in the corners compared to 19s. I noticed a huge difference with I changed to an 18 on my 500. Not in weight but in corners. I'm a 19 fan for MX and for outdoors peroid.

[Polar-Bus]

In what areas are one better than the other over  ?

I've run both, and generally speaking 18's are preferred by enduro guys for a more forgiving ride over rocky terrain. 18's generally offer a larger "aspect ratio" which means more flex in the sidewall. 19's are stiffer, and more accurate feel railing through rutted berms. At my amatuer level of riding, i don't notice a huge difference between the 2, but there is different behavior. 

[Paul]

When I raced Open Pro out here in the desert I ran a 20" front and an 18" rear. Gotta love the sidewall in a 125+ mile race over the nastiest crap in the desert I don't MX so I don't have a need for a 19".