18 or 17 inch wheels?

Hello all, this is my 1st post, up till now I have always found my answers in the forum.
A great forum at that I might add.

I have a KZ900 that I am going to be putting new wire spoked wheels on.
It currently has 18x3.5 rear and 18x2.5 front.
My dilemma is whether to go with 18 or 17 inch wheels.
Whatever size I get the front will be 3.5 wide and rear 5.5 wide.
The nice thing with the 17s is the wide selection of sport bike tires/compounds available. The 18s have a limited selection mostly sport touring and touring.

Any feedback / suggestions?

Thanks!

Are you upgrading your forks also? Or just putting a smaller diameter wheel on a forks/frame designed for a different geometry (e.g. 19" wheel)?

I was planning to build the front end around the wheel/tire combo. The bike I road raced in the early ‘80s and has modified police forks, I also have some ZX and late model GSXR forks as a backup if those don’t work out. The steering head is still at the stock angle, if I needed too raise front of the bike up, regardless of which forks I use, my thoughts were to make short extensions for the top of the tubes, these would thread into the tubes in place of the cap, I shouldn’t have to raise it more than an inch with the 17s. The rear has forward mounted shocks that raise the rear about ½ inch.

The old wheels were going on another KZ900 that will be a period sport bike with crusty old race / performance parts from the ‘70s to early ‘80s. On this one the frame will be left alone, no braces, forward mount shocks, etc.

Z_One check out my bike in projects (my 1974 z1-900 conversion) I have 17" wheels on my bike this seems to be the hot new thing along with the modern forks, swing-arm the beifits of a better ride, tire selection and brakes is hard to beat thats my 2-cents.

I put 17" wheels w/radial tires on my '73 Z1-900. The handling/braking improved as a result -- not just because of the 17" wheels and radial tires but also because of the frame mods, Works rear shocks, modified front forks, '79-'80 KZ1000 front brake calipers, and a '78 KZ1000 rear caliper/disc.

I think a lot of what we do is for appearnace first. The changes that are made to the geometry are not taken into consideration by MOST. I fall into this category too, since I know so little about the bike's geometry and what is better or even right... Since you are asking and there are some really qualified memebers here, I would like to see some feedback as to possible alternatives and implications to handling, steering and weight distribution.

I know that I really like my Pirelli Sport Demons that I just added SEE this post Just a few miles on them, but a noticable difference (better) in corning, whiched I never liked on this bike (in comparison to newer sportbikes... :dry: )