New Tires

I'm looking to go with 110/90V-16 up front and 120/90V-18 in the back. I was going to go with 120/80V-16 up front and 130/80V-18 in the back but I'm afraid going up two sizes is a bit much.

Any issues with either size?

I'm going with the Metzeler Lasertecs; I have a set on my bike now, and I have no complaints.

 

IIRC (correct me if I'm wrong), the OE sizes for the mini-'Ceptor are 100/90-16-F & 110/90-16-R.

One of that bike's best and most admired qualities is it's light and nimble handling.
Wider tires, especially at the front, negate this and cause heavier and slower steering and transitions.
Admittedly, even a 130mm rear is still relatively narrow, but it's substantially wider than stock.

It seems the primary reason that most riders want wider tires is for more grip at extreme lean angles.
In this case, I can vouch that the stock size tires, especially with excellent Metzeler Lasertecs is quite sufficient.
*I rode the heck out of a VF500 years ago on comparatively much harder and less grippy tires (Dunlop K391's) and never really needed more.

The other consideration is the optimum tire width for a given rim width.
Too wide a tire for a certain rim width does weird things to the tires' profile, and can actually have the undesired result of less contact patch available at a given lean angle, and often results in a wide band of unuseable tread at the extreme edges ("chicken strips") - You simply cannot utilize the full tread width without dragging such hard parts as say, the bar ends and mirrors..., or perhaps also removing your centerstand, footpegs, exhaust system and outer case covers... ;-)

Personally, If I were you, I'd be curious to consider up to 1 size wider than than OE fitment (110/90-16-F, 120/90-16-R), but no more.

Another consideration, especially at the front, is that these sizes are not only slightly wider, but also slightly taller than the stock tires.
This can cause issues of altering the ride height/chassis attitude causing some undesired handling woes, as well as simply physically interfering with the front fender both at the sides and the top (overall diameter - rubbing the underside of the fender).
The rear tire should clear, as there is no "hugger" to be concerned about, but many older bikes have very narrow swingarms, as well as possible interference with the chain and/or brake stay arm, etc.

Frankly, I think the best solution would be to stay with the stock size front (the Metzeler ME33 front is an OUTSTANDING tire, and will provide all the grip you really need), and perhaps bump up 1 size in the rear (120/90-16).

Keep in mind, that with the 500's 16-inch front wheel the handling is already quick, bordering on twitchy, and raising the rear ride height via a taller rear tire relative to the front will likely push the handling even further towards the squirelly end of the spectrum.
If you find the resulting steering to be too quick for your tastes, you can offset this easily and cheaply (*free*!!) by lowering the fork stanchion tubes in the triple clamps a bit, effectively raising the front end a bit to match the raised rear end.
I'd start with about 6mm, maybe up to about 10mm to restore the original handling qualities.
*You can always measure the actual OD's of the old tire and new tire to determine the precise amount, but it doesn't need to be an exact science for street work - close enough for your tastes is good enough.

Of course, all of this grand experiment is limited by just what size tires are even available in 16's any more...

 

Very good info, thank you!

Standard:
Front Tire: 100/90-16
Rear Tire: 110/90-18

Mine:
Front Tire: 110/90-16
Rear Tire: 120/90-18

 

D'Oh!!
That's what I meant...

Mea Culpa

I'm assuming you've had no clearance problems with the wider front??
Good to know for others considering this mod.

 

I ended up going with Metzeler Lasertec tires.

Front: 110/90-16
Rear: 120/90-18

I got them for $202 shipped to my front door. They should be here next week and going on the bike with a new chain and sprockets first week in March.