16\" rear vs 18\" on 79' KZ650

Hello!
Question; what is the difference in handling/performance between a 16" rear and a 18" on a 79KZ650?
If you could give me a clue as to the gear ratio conversion that would be cool too. Thanks!

Not a KZ650, but very close:

My KZ750H has a 16" rear wheel, and my KZ750E has an 18" rear wheel.

The 16" tire is much fatter than the 18", so the outside diameter and overall height of the two tires are virtually the same. The 16" seems to have a greater contact patch, and is more sure-footed on uneven freeway surfaces (i.e., grooves, and lines between concrete pads). The 18" allows me to lean over more quickly, and allows the steering to be more responsive in the twisties. BUT, there is not a great deal of difference between the two.
/

I agree with apeman.
I have 16 on my 79 1000LTD, and 18 on the 77 650.
I like the smoother ride on the 79 for longer distances, and I like the 650's ride for in town.

Interesting thread - I just picked up a 650 with a 16" rear wheel and happen to have an extra 18" rear wheel. I'd like to change it because I like the look of the 18" much better. I also think it handles better and you can go with a lower profile tire on the 18, which also looks good. (to me anyway) Keep us posted and show us some pictures. We LOVE pictures here!!

I agree too. 18" is better looking and works better in my opinion. I'll have to admit though all my miles have been with 18" rear wheels except for about 200 on the KZ1000ST (17"), and 200 on a 900LTD (16"). I know that 900LTD was inferior in ever way imaginable to a standard KZ900 or 1000 and at least some of it was due to the 16" wheel in my opinion at least. The ST is a fabulous bike though. I'd have to do some measuring, but a stock 4.00-18 would be a 100% aspect tire and any 16" regardless of the width will be at the maximum a 90% and more likely a 80% aspect tire so the circumference should be much less on a 16" tire. So a 4.00 on a 18" wheel would stand about 22" high give or take, and a 5 1/2" wide 16" would stand about 20 1/2" high. I'm too lazy and old to compute the difference 1 1/2" height would make, but I would guess 500-600 additional rpms at highway speed.

Post edited by: RonKZ650, at: 2007/10/09 23:07

Thanks all!
Nothing is simple, I have decided to replace the 16" wheel wth the 18" rear wheel from my running parts bike as well as the rear fender and stock lights that were taken off by previous ownwer (Cafe Style). I like chrome, and an upright riding position, old I guess!
Bike is in a repair shop in Oregon, pics forthcoming.