I've noticed over the course of owning my 85, that each and every time I ever experience a high speed wobble of any sort, it was always, and I repeat here - always - traced back to the back tire. New tire=wobble be gone. That's just my experience. I never rode hard enough in the twisties back then to ever worry about bracing - forks, or frame. I always made due with the OEM setup. Still do to this day. So, when I ask questions regarding fork bracing, I really am in the learning mode and want to know why they should, or should not, work.
Regarding tires. Over the years since new, my 85 always wore OEM Dunlops, and I usually average around 2K miles for each rear tire. Since buying my 09, and relegating my 85 to what amounts to a daily to/from work rider, last time I needed rear rubber, I decided to save a bit of money and at the same time, try to achieve a bit better mileage out of it by getting my first (OEM size) Shinko for the bike. Less than 400 miles later, that darn Shinko has developed the absolute WORST lateral run-out I have ever witnessed in a tire. I can feel that sucker wanting to wobble 100% of the time. But since I only do 12 miles round trip to work, and don't always get to ride, weather permitting, I have put up with it for over a year now. If I ever wanted to take that bike down to the AR twisties, I'd have to change back to my old faithful Dunlops beforehand. NOTHING WORSE THAN A GEN 1 VMAX IN A LONG, FAST SWEEPER WITH A BACK TIRE CONTAINING LATERAL RUNOUT. Wobbling in a sweeper at over 60-100mph ain't no fun!
I wonder since you don't ride it that often if the reason you see lateral run out. Maybe its soft enough that it settles while the bike sits in one spot for periods of time.
I have heard of people getting a bad Shinko ( which I have heard the same thing about other major name tires ), but I can only say I have run atleast 10 sets of Shinko's on my last few bikes and never had one shimmy shake or problem UNTIL the front tire had mileage on it. And by Mileage I mean usually 6000-8000 miles. Which is almost the life of the tire for the softer tires. 10,000 is when I changed the last one, and I only stretched it out because I was taking a trip and I had that planned, or I would have changed it sooner.
The Busa rear tire only lasted around 800 miles, but that was alot of power being put down on that tire and it was expected to do alot.
The Shinko on the rear of the Vmax NEVER gave me a problem ever, it was ALWAYS the front that gave me shake. I don't think you could really feel the shake of a rear tire comparably to the front tire ( thats not even a "I dont think" , thats a definite no, you can't feel the same shake from the front to rear tire , its totally different feeling ).
I just want to check, you meant the rear tire correct? Not the front tire?
And my other thought would be the middle strip on the Shinko does grab WAY differently than the stock Dunlop does. That strip in the Shinko you will feel on certain roads as it "crowns" the road. So that might what you felt?
I bought a 97 Vmax last year and it had Metzler tires on it. Those were the worst tires I ever had on a Vmax. They were so hard, that when you got on it in 1st gear it would break loose and slide you all over. It may be cool if you want to do smoke shows and rolling burnouts in second gear, but it was terrible for any sort of traction. I almost dumped the bike with the Metzler LOL. When I rode my 99 home ( with the Shinko ), I was utterly amazed at how even just coasting through a turn it gripped that much better than the Metzler.
So the Shinko's are SUPER soft, you don't get the mileage and you go through them fast. But if you want uber traction then thats the price you pay for it. And I will say that if I had something like a stock Dunlap or Metzler on my 99 when I was racing it, I would probably not have broken drive shafts as much as I did, because I am sure the tire would have spun and not gripped like the Shinko did.
Todd