18" vs 19"

[dprider]

Hey. Quick q. What effect does rear wheel size have on overall performance? Ex.: 19" on an MX vs 18" on enduros?
If I'm getting an MXer(yz) but riding offroad/scrambles/enduro comps it doesn't make sense to make the 19" to 18" swap unless there is a good enough reason. :coocoo:

 

[2 strokes for life]

I am not sure but i think an 18 rear wheel is less prone to pinch flats and the side walls are more supported so less objects penitrait through the tire.

 

[RM_guy]

Both the 18 and 19" rear wheel have the same outside diameter tire so gearing is not affected. The 19" wheel uses a tire that has a shorter and therefore stiffer side wall that doesn't let the rear end wallow around in turns. It gives a more precise feel. It is also a bit lighter due to less rubber and that reduces unsprung weight that can greatly help the suspension.

The trade off is that it is more susceptible to pinch flats since there is less room for the tire to compress before it hits the rim. Real diehards will have both an 18" and 19" wheel to swap out depending on what they are riding. Most of us aren't quite that diehard and just run the 19" in both MX and woods without a huge problem. You can always use a heavy duty tube is you're concerned about flats or just boost up the air pressure for real rocky or high speed riding.

 

[SpeedyManiac]

I find the 19" rear tire handles weird in the woods, especially on bumpy roots and rocks.

 

[RM_guy]

Yeah, another thing about the 18". With the longer sidewalls it soaks up hits more readily. A 19" wheel needs more air to prevent pinch flats so it makes it hard and less forgiving than the 18" which can get away with less air.

 

[OHIOMOTOXER]

MAN am I out of it....

Last bike I had had a 17 inch rear tire......

Just kidding, I've had much newer bikes since that 1980 390 Husqvarna.

Ive raced with them all even the Honda 23 inch front wheel.....couldnt tell much difference in any of them.....but then again I'm just a hare scrambles rider.

That 17 with a terraflex did really lay down a nice foot print though.